X Tutup
/* * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. * * * * * * * * * * * * * * * * * * * * */ package java.net; import java.io.IOException; import java.io.InvalidObjectException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Serializable; import java.nio.ByteBuffer; import java.nio.CharBuffer; import java.nio.charset.CharsetDecoder; import java.nio.charset.CharsetEncoder; import java.nio.charset.CoderResult; import java.nio.charset.CodingErrorAction; import java.nio.charset.CharacterCodingException; import java.text.Normalizer; import sun.nio.cs.ThreadLocalCoders; import java.lang.Character; // for javadoc import java.lang.NullPointerException; // for javadoc /** * Represents a Uniform Resource Identifier (URI) reference. * *

Aside from some minor deviations noted below, an instance of this * class represents a URI reference as defined by * RFC 2396: Uniform * Resource Identifiers (URI): Generic Syntax, amended by RFC 2732: Format for * Literal IPv6 Addresses in URLs. The Literal IPv6 address format * also supports scope_ids. The syntax and usage of scope_ids is described * here. * This class provides constructors for creating URI instances from * their components or by parsing their string forms, methods for accessing the * various components of an instance, and methods for normalizing, resolving, * and relativizing URI instances. Instances of this class are immutable. * * *

URI syntax and components

* * At the highest level a URI reference (hereinafter simply "URI") in string * form has the syntax * *
* [scheme{@code :}]scheme-specific-part[{@code #}fragment] *
* * where square brackets [...] delineate optional components and the characters * {@code :} and {@code #} stand for themselves. * *

An absolute URI specifies a scheme; a URI that is not absolute is * said to be relative. URIs are also classified according to whether * they are opaque or hierarchical. * *

An opaque URI is an absolute URI whose scheme-specific part does * not begin with a slash character ({@code '/'}). Opaque URIs are not * subject to further parsing. Some examples of opaque URIs are: * *

* * * *
{@code mailto:java-net@java.sun.com}
{@code news:comp.lang.java}
{@code urn:isbn:096139210x}
* *

A hierarchical URI is either an absolute URI whose * scheme-specific part begins with a slash character, or a relative URI, that * is, a URI that does not specify a scheme. Some examples of hierarchical * URIs are: * *

* {@code http://java.sun.com/j2se/1.3/}
* {@code docs/guide/collections/designfaq.html#28}
* {@code ../../../demo/jfc/SwingSet2/src/SwingSet2.java}
* {@code file:///~/calendar} *
* *

A hierarchical URI is subject to further parsing according to the syntax * *

* [scheme{@code :}][{@code //}authority][path][{@code ?}query][{@code #}fragment] *
* * where the characters {@code :}, {@code /}, * {@code ?}, and {@code #} stand for themselves. The * scheme-specific part of a hierarchical URI consists of the characters * between the scheme and fragment components. * *

The authority component of a hierarchical URI is, if specified, either * server-based or registry-based. A server-based authority * parses according to the familiar syntax * *

* [user-info{@code @}]host[{@code :}port] *
* * where the characters {@code @} and {@code :} stand for * themselves. Nearly all URI schemes currently in use are server-based. An * authority component that does not parse in this way is considered to be * registry-based. * *

The path component of a hierarchical URI is itself said to be absolute * if it begins with a slash character ({@code '/'}); otherwise it is * relative. The path of a hierarchical URI that is either absolute or * specifies an authority is always absolute. * *

All told, then, a URI instance has the following nine components: * *

* * * * * * * * * * *
ComponentType
scheme{@code String}
scheme-specific-part    {@code String}
authority{@code String}
user-info{@code String}
host{@code String}
port{@code int}
path{@code String}
query{@code String}
fragment{@code String}
* * In a given instance any particular component is either undefined or * defined with a distinct value. Undefined string components are * represented by {@code null}, while undefined integer components are * represented by {@code -1}. A string component may be defined to have the * empty string as its value; this is not equivalent to that component being * undefined. * *

Whether a particular component is or is not defined in an instance * depends upon the type of the URI being represented. An absolute URI has a * scheme component. An opaque URI has a scheme, a scheme-specific part, and * possibly a fragment, but has no other components. A hierarchical URI always * has a path (though it may be empty) and a scheme-specific-part (which at * least contains the path), and may have any of the other components. If the * authority component is present and is server-based then the host component * will be defined and the user-information and port components may be defined. * * *

Operations on URI instances

* * The key operations supported by this class are those of * normalization, resolution, and relativization. * *

Normalization is the process of removing unnecessary {@code "."} * and {@code ".."} segments from the path component of a hierarchical URI. * Each {@code "."} segment is simply removed. A {@code ".."} segment is * removed only if it is preceded by a non-{@code ".."} segment. * Normalization has no effect upon opaque URIs. * *

Resolution is the process of resolving one URI against another, * base URI. The resulting URI is constructed from components of both * URIs in the manner specified by RFC 2396, taking components from the * base URI for those not specified in the original. For hierarchical URIs, * the path of the original is resolved against the path of the base and then * normalized. The result, for example, of resolving * *

* {@code docs/guide/collections/designfaq.html#28} *              *     (1) *
* * against the base URI {@code http://java.sun.com/j2se/1.3/} is the result * URI * *
* {@code https://docs.oracle.com/javase/1.3/docs/guide/collections/designfaq.html#28} *
* * Resolving the relative URI * *
* {@code ../../../demo/jfc/SwingSet2/src/SwingSet2.java}    (2) *
* * against this result yields, in turn, * *
* {@code http://java.sun.com/j2se/1.3/demo/jfc/SwingSet2/src/SwingSet2.java} *
* * Resolution of both absolute and relative URIs, and of both absolute and * relative paths in the case of hierarchical URIs, is supported. Resolving * the URI {@code file:///~calendar} against any other URI simply yields the * original URI, since it is absolute. Resolving the relative URI (2) above * against the relative base URI (1) yields the normalized, but still relative, * URI * *
* {@code demo/jfc/SwingSet2/src/SwingSet2.java} *
* *

Relativization, finally, is the inverse of resolution: For any * two normalized URIs u and v, * *

* u{@code .relativize(}u{@code .resolve(}v{@code )).equals(}v{@code )}  and
* u{@code .resolve(}u{@code .relativize(}v{@code )).equals(}v{@code )}  .
*
* * This operation is often useful when constructing a document containing URIs * that must be made relative to the base URI of the document wherever * possible. For example, relativizing the URI * *
* {@code https://docs.oracle.com/javase/1.3/docs/guide/index.html} *
* * against the base URI * *
* {@code http://java.sun.com/j2se/1.3} *
* * yields the relative URI {@code docs/guide/index.html}. * * *

Character categories

* * RFC 2396 specifies precisely which characters are permitted in the * various components of a URI reference. The following categories, most of * which are taken from that specification, are used below to describe these * constraints: * *
* * * * * * * * * * * * * * * * *
alphaThe US-ASCII alphabetic characters, * {@code 'A'} through {@code 'Z'} * and {@code 'a'} through {@code 'z'}
digitThe US-ASCII decimal digit characters, * {@code '0'} through {@code '9'}
alphanumAll alpha and digit characters
unreserved    All alphanum characters together with those in the string * {@code "_-!.~'()*"}
punctThe characters in the string {@code ",;:$&+="}
reservedAll punct characters together with those in the string * {@code "?/[]@"}
escapedEscaped octets, that is, triplets consisting of the percent * character ({@code '%'}) followed by two hexadecimal digits * ({@code '0'}-{@code '9'}, {@code 'A'}-{@code 'F'}, and * {@code 'a'}-{@code 'f'})
otherThe Unicode characters that are not in the US-ASCII character set, * are not control characters (according to the {@link * java.lang.Character#isISOControl(char) Character.isISOControl} * method), and are not space characters (according to the {@link * java.lang.Character#isSpaceChar(char) Character.isSpaceChar} * method)  (Deviation from RFC 2396, which is * limited to US-ASCII)
* *

The set of all legal URI characters consists of * the unreserved, reserved, escaped, and other * characters. * * *

Escaped octets, quotation, encoding, and decoding

* * RFC 2396 allows escaped octets to appear in the user-info, path, query, and * fragment components. Escaping serves two purposes in URIs: * * * * These purposes are served in this class by three related operations: * * * * These operations are exposed in the constructors and methods of this class * as follows: * * * * *

Identities

* * For any URI u, it is always the case that * *
* {@code new URI(}u{@code .toString()).equals(}u{@code )} . *
* * For any URI u that does not contain redundant syntax such as two * slashes before an empty authority (as in {@code file:///tmp/} ) or a * colon following a host name but no port (as in * {@code http://java.sun.com:} ), and that does not encode characters * except those that must be quoted, the following identities also hold: * 
 *     new URI(u.getScheme(),
 *             u.getSchemeSpecificPart(),
 *             u.getFragment())
 *     .equals(u)
* in all cases, * 
 *     new URI(u.getScheme(),
 *             u.getUserInfo(), u.getAuthority(),
 *             u.getPath(), u.getQuery(),
 *             u.getFragment())
 *     .equals(u)
* if u is hierarchical, and * 
 *     new URI(u.getScheme(),
 *             u.getUserInfo(), u.getHost(), u.getPort(),
 *             u.getPath(), u.getQuery(),
 *             u.getFragment())
 *     .equals(u)
* if u is hierarchical and has either no authority or a server-based * authority. * * *

URIs, URLs, and URNs

* * A URI is a uniform resource identifier while a URL is a uniform * resource locator. Hence every URL is a URI, abstractly speaking, but * not every URI is a URL. This is because there is another subcategory of * URIs, uniform resource names (URNs), which name resources but do not * specify how to locate them. The {@code mailto}, {@code news}, and * {@code isbn} URIs shown above are examples of URNs. * *

The conceptual distinction between URIs and URLs is reflected in the * differences between this class and the {@link URL} class. * *

An instance of this class represents a URI reference in the syntactic * sense defined by RFC 2396. A URI may be either absolute or relative. * A URI string is parsed according to the generic syntax without regard to the * scheme, if any, that it specifies. No lookup of the host, if any, is * performed, and no scheme-dependent stream handler is constructed. Equality, * hashing, and comparison are defined strictly in terms of the character * content of the instance. In other words, a URI instance is little more than * a structured string that supports the syntactic, scheme-independent * operations of comparison, normalization, resolution, and relativization. * *

An instance of the {@link URL} class, by contrast, represents the * syntactic components of a URL together with some of the information required * to access the resource that it describes. A URL must be absolute, that is, * it must always specify a scheme. A URL string is parsed according to its * scheme. A stream handler is always established for a URL, and in fact it is * impossible to create a URL instance for a scheme for which no handler is * available. Equality and hashing depend upon both the scheme and the * Internet address of the host, if any; comparison is not defined. In other * words, a URL is a structured string that supports the syntactic operation of * resolution as well as the network I/O operations of looking up the host and * opening a connection to the specified resource. * * * @author Mark Reinhold * @since 1.4 * * @see RFC 2279: UTF-8, a * transformation format of ISO 10646,
RFC 2373: IPv6 Addressing * Architecture,
RFC 2396: Uniform * Resource Identifiers (URI): Generic Syntax,
RFC 2732: Format for * Literal IPv6 Addresses in URLs,
URISyntaxException */ public final class URI implements Comparable, Serializable { // Note: Comments containing the word "ASSERT" indicate places where a // throw of an InternalError should be replaced by an appropriate assertion // statement once asserts are enabled in the build. static final long serialVersionUID = -6052424284110960213L; // -- Properties and components of this instance -- // Components of all URIs: [:][#] private transient String scheme; // null ==> relative URI private transient String fragment; // Hierarchical URI components: [//][?] private transient String authority; // Registry or server // Server-based authority: [@][:] private transient String userInfo; private transient String host; // null ==> registry-based private transient int port = -1; // -1 ==> undefined // Remaining components of hierarchical URIs private transient String path; // null ==> opaque private transient String query; // The remaining fields may be computed on demand private volatile transient String schemeSpecificPart; private volatile transient int hash; // Zero ==> undefined private volatile transient String decodedUserInfo = null; private volatile transient String decodedAuthority = null; private volatile transient String decodedPath = null; private volatile transient String decodedQuery = null; private volatile transient String decodedFragment = null; private volatile transient String decodedSchemeSpecificPart = null; /** * The string form of this URI. * * @serial */ private volatile String string; // The only serializable field // -- Constructors and factories -- private URI() { } // Used internally /** * Constructs a URI by parsing the given string. * *

This constructor parses the given string exactly as specified by the * grammar in RFC 2396, * Appendix A, except for the following deviations:

* * * * @param str The string to be parsed into a URI * * @throws NullPointerException * If {@code str} is {@code null} * * @throws URISyntaxException * If the given string violates RFC 2396, as augmented * by the above deviations */ public URI(String str) throws URISyntaxException { new Parser(str).parse(false); } /** * Constructs a hierarchical URI from the given components. * *

If a scheme is given then the path, if also given, must either be * empty or begin with a slash character ({@code '/'}). Otherwise a * component of the new URI may be left undefined by passing {@code null} * for the corresponding parameter or, in the case of the {@code port} * parameter, by passing {@code -1}. * *

This constructor first builds a URI string from the given components * according to the rules specified in RFC 2396, * section 5.2, step 7:

* *
    * *

  1. Initially, the result string is empty.

    2. * *

  2. If a scheme is given then it is appended to the result, * followed by a colon character ({@code ':'}).

    3. * *

  3. If user information, a host, or a port are given then the * string {@code "//"} is appended.

    4. * *

  4. If user information is given then it is appended, followed by * a commercial-at character ({@code '@'}). Any character not in the * unreserved, punct, escaped, or other * categories is quoted.

    5. * *

  5. If a host is given then it is appended. If the host is a * literal IPv6 address but is not enclosed in square brackets * ({@code '['} and {@code ']'}) then the square brackets are added. *

    6. * *

  6. If a port number is given then a colon character * ({@code ':'}) is appended, followed by the port number in decimal. *

    7. * *

  7. If a path is given then it is appended. Any character not in * the unreserved, punct, escaped, or other * categories, and not equal to the slash character ({@code '/'}) or the * commercial-at character ({@code '@'}), is quoted.

    8. * *

  8. If a query is given then a question-mark character * ({@code '?'}) is appended, followed by the query. Any character that * is not a legal URI character is quoted. *

    9. * *

  9. Finally, if a fragment is given then a hash character * ({@code '#'}) is appended, followed by the fragment. Any character * that is not a legal URI character is quoted.

    10. * *
* *

The resulting URI string is then parsed as if by invoking the {@link * #URI(String)} constructor and then invoking the {@link * #parseServerAuthority()} method upon the result; this may cause a {@link * URISyntaxException} to be thrown.

* * @param scheme Scheme name * @param userInfo User name and authorization information * @param host Host name * @param port Port number * @param path Path * @param query Query * @param fragment Fragment * * @throws URISyntaxException * If both a scheme and a path are given but the path is relative, * if the URI string constructed from the given components violates * RFC 2396, or if the authority component of the string is * present but cannot be parsed as a server-based authority */ public URI(String scheme, String userInfo, String host, int port, String path, String query, String fragment) throws URISyntaxException { String s = toString(scheme, null, null, userInfo, host, port, path, query, fragment); checkPath(s, scheme, path); new Parser(s).parse(true); } /** * Constructs a hierarchical URI from the given components. * *

If a scheme is given then the path, if also given, must either be * empty or begin with a slash character ({@code '/'}). Otherwise a * component of the new URI may be left undefined by passing {@code null} * for the corresponding parameter. * *

This constructor first builds a URI string from the given components * according to the rules specified in RFC 2396, * section 5.2, step 7:

* *
    * *

  1. Initially, the result string is empty.

    2. * *

  2. If a scheme is given then it is appended to the result, * followed by a colon character ({@code ':'}).

    3. * *

  3. If an authority is given then the string {@code "//"} is * appended, followed by the authority. If the authority contains a * literal IPv6 address then the address must be enclosed in square * brackets ({@code '['} and {@code ']'}). Any character not in the * unreserved, punct, escaped, or other * categories, and not equal to the commercial-at character * ({@code '@'}), is quoted.

    4. * *

  4. If a path is given then it is appended. Any character not in * the unreserved, punct, escaped, or other * categories, and not equal to the slash character ({@code '/'}) or the * commercial-at character ({@code '@'}), is quoted.

    5. * *

  5. If a query is given then a question-mark character * ({@code '?'}) is appended, followed by the query. Any character that * is not a legal URI character is quoted. *

    6. * *

  6. Finally, if a fragment is given then a hash character * ({@code '#'}) is appended, followed by the fragment. Any character * that is not a legal URI character is quoted.

    7. * *
* *

The resulting URI string is then parsed as if by invoking the {@link * #URI(String)} constructor and then invoking the {@link * #parseServerAuthority()} method upon the result; this may cause a {@link * URISyntaxException} to be thrown.

* * @param scheme Scheme name * @param authority Authority * @param path Path * @param query Query * @param fragment Fragment * * @throws URISyntaxException * If both a scheme and a path are given but the path is relative, * if the URI string constructed from the given components violates * RFC 2396, or if the authority component of the string is * present but cannot be parsed as a server-based authority */ public URI(String scheme, String authority, String path, String query, String fragment) throws URISyntaxException { String s = toString(scheme, null, authority, null, null, -1, path, query, fragment); checkPath(s, scheme, path); new Parser(s).parse(false); } /** * Constructs a hierarchical URI from the given components. * *

A component may be left undefined by passing {@code null}. * *

This convenience constructor works as if by invoking the * seven-argument constructor as follows: * *

* {@code new} {@link #URI(String, String, String, int, String, String, String) * URI}{@code (scheme, null, host, -1, path, null, fragment);} *
* * @param scheme Scheme name * @param host Host name * @param path Path * @param fragment Fragment * * @throws URISyntaxException * If the URI string constructed from the given components * violates RFC 2396 */ public URI(String scheme, String host, String path, String fragment) throws URISyntaxException { this(scheme, null, host, -1, path, null, fragment); } /** * Constructs a URI from the given components. * *

A component may be left undefined by passing {@code null}. * *

This constructor first builds a URI in string form using the given * components as follows:

* *
    * *

  1. Initially, the result string is empty.

    2. * *

  2. If a scheme is given then it is appended to the result, * followed by a colon character ({@code ':'}).

    3. * *

  3. If a scheme-specific part is given then it is appended. Any * character that is not a legal URI character * is quoted.

    4. * *

  4. Finally, if a fragment is given then a hash character * ({@code '#'}) is appended to the string, followed by the fragment. * Any character that is not a legal URI character is quoted.

    5. * *
* *

The resulting URI string is then parsed in order to create the new * URI instance as if by invoking the {@link #URI(String)} constructor; * this may cause a {@link URISyntaxException} to be thrown.

* * @param scheme Scheme name * @param ssp Scheme-specific part * @param fragment Fragment * * @throws URISyntaxException * If the URI string constructed from the given components * violates RFC 2396 */ public URI(String scheme, String ssp, String fragment) throws URISyntaxException { new Parser(toString(scheme, ssp, null, null, null, -1, null, null, fragment)) .parse(false); } /** * Creates a URI by parsing the given string. * *

This convenience factory method works as if by invoking the {@link * #URI(String)} constructor; any {@link URISyntaxException} thrown by the * constructor is caught and wrapped in a new {@link * IllegalArgumentException} object, which is then thrown. * *

This method is provided for use in situations where it is known that * the given string is a legal URI, for example for URI constants declared * within in a program, and so it would be considered a programming error * for the string not to parse as such. The constructors, which throw * {@link URISyntaxException} directly, should be used situations where a * URI is being constructed from user input or from some other source that * may be prone to errors.

* * @param str The string to be parsed into a URI * @return The new URI * * @throws NullPointerException * If {@code str} is {@code null} * * @throws IllegalArgumentException * If the given string violates RFC 2396 */ public static URI create(String str) { try { return new URI(str); } catch (URISyntaxException x) { throw new IllegalArgumentException(x.getMessage(), x); } } // -- Operations -- /** * Attempts to parse this URI's authority component, if defined, into * user-information, host, and port components. * *

If this URI's authority component has already been recognized as * being server-based then it will already have been parsed into * user-information, host, and port components. In this case, or if this * URI has no authority component, this method simply returns this URI. * *

Otherwise this method attempts once more to parse the authority * component into user-information, host, and port components, and throws * an exception describing why the authority component could not be parsed * in that way. * *

This method is provided because the generic URI syntax specified in * RFC 2396 * cannot always distinguish a malformed server-based authority from a * legitimate registry-based authority. It must therefore treat some * instances of the former as instances of the latter. The authority * component in the URI string {@code "//foo:bar"}, for example, is not a * legal server-based authority but it is legal as a registry-based * authority. * *

In many common situations, for example when working URIs that are * known to be either URNs or URLs, the hierarchical URIs being used will * always be server-based. They therefore must either be parsed as such or * treated as an error. In these cases a statement such as * *

* {@code URI }u{@code = new URI(str).parseServerAuthority();} *
* *

can be used to ensure that u always refers to a URI that, if * it has an authority component, has a server-based authority with proper * user-information, host, and port components. Invoking this method also * ensures that if the authority could not be parsed in that way then an * appropriate diagnostic message can be issued based upon the exception * that is thrown.

* * @return A URI whose authority field has been parsed * as a server-based authority * * @throws URISyntaxException * If the authority component of this URI is defined * but cannot be parsed as a server-based authority * according to RFC 2396 */ public URI parseServerAuthority() throws URISyntaxException { // We could be clever and cache the error message and index from the // exception thrown during the original parse, but that would require // either more fields or a more-obscure representation. if ((host != null) || (authority == null)) return this; defineString(); new Parser(string).parse(true); return this; } /** * Normalizes this URI's path. * *

If this URI is opaque, or if its path is already in normal form, * then this URI is returned. Otherwise a new URI is constructed that is * identical to this URI except that its path is computed by normalizing * this URI's path in a manner consistent with RFC 2396, * section 5.2, step 6, sub-steps c through f; that is: *

* *
    * *

  1. All {@code "."} segments are removed.

    2. * *

  2. If a {@code ".."} segment is preceded by a non-{@code ".."} * segment then both of these segments are removed. This step is * repeated until it is no longer applicable.

    3. * *

  3. If the path is relative, and if its first segment contains a * colon character ({@code ':'}), then a {@code "."} segment is * prepended. This prevents a relative URI with a path such as * {@code "a:b/c/d"} from later being re-parsed as an opaque URI with a * scheme of {@code "a"} and a scheme-specific part of {@code "b/c/d"}. * (Deviation from RFC 2396)

    4. * *
* *

A normalized path will begin with one or more {@code ".."} segments * if there were insufficient non-{@code ".."} segments preceding them to * allow their removal. A normalized path will begin with a {@code "."} * segment if one was inserted by step 3 above. Otherwise, a normalized * path will not contain any {@code "."} or {@code ".."} segments.

* * @return A URI equivalent to this URI, * but whose path is in normal form */ public URI normalize() { return normalize(this); } /** * Resolves the given URI against this URI. * *

If the given URI is already absolute, or if this URI is opaque, then * the given URI is returned. * *

If the given URI's fragment component is * defined, its path component is empty, and its scheme, authority, and * query components are undefined, then a URI with the given fragment but * with all other components equal to those of this URI is returned. This * allows a URI representing a standalone fragment reference, such as * {@code "#foo"}, to be usefully resolved against a base URI. * *

Otherwise this method constructs a new hierarchical URI in a manner * consistent with RFC 2396, * section 5.2; that is:

* *
    * *

  1. A new URI is constructed with this URI's scheme and the given * URI's query and fragment components.

    2. * *

  2. If the given URI has an authority component then the new URI's * authority and path are taken from the given URI.

    3. * *

  3. Otherwise the new URI's authority component is copied from * this URI, and its path is computed as follows:

    * *
      * *

    1. If the given URI's path is absolute then the new URI's path * is taken from the given URI.

      2. * *

    2. Otherwise the given URI's path is relative, and so the new * URI's path is computed by resolving the path of the given URI * against the path of this URI. This is done by concatenating all but * the last segment of this URI's path, if any, with the given URI's * path and then normalizing the result as if by invoking the {@link * #normalize() normalize} method.

      3. * *
    4. * *
* *

The result of this method is absolute if, and only if, either this * URI is absolute or the given URI is absolute.

* * @param uri The URI to be resolved against this URI * @return The resulting URI * * @throws NullPointerException * If {@code uri} is {@code null} */ public URI resolve(URI uri) { return resolve(this, uri); } /** * Constructs a new URI by parsing the given string and then resolving it * against this URI. * *

This convenience method works as if invoking it were equivalent to * evaluating the expression {@link #resolve(java.net.URI) * resolve}{@code (URI.}{@link #create(String) create}{@code (str))}.

* * @param str The string to be parsed into a URI * @return The resulting URI * * @throws NullPointerException * If {@code str} is {@code null} * * @throws IllegalArgumentException * If the given string violates RFC 2396 */ public URI resolve(String str) { return resolve(URI.create(str)); } /** * Relativizes the given URI against this URI. * *

The relativization of the given URI against this URI is computed as * follows:

* *
    * *

  1. If either this URI or the given URI are opaque, or if the * scheme and authority components of the two URIs are not identical, or * if the path of this URI is not a prefix of the path of the given URI, * then the given URI is returned.

    2. * *

  2. Otherwise a new relative hierarchical URI is constructed with * query and fragment components taken from the given URI and with a path * component computed by removing this URI's path from the beginning of * the given URI's path.

    3. * *
* * @param uri The URI to be relativized against this URI * @return The resulting URI * * @throws NullPointerException * If {@code uri} is {@code null} */ public URI relativize(URI uri) { return relativize(this, uri); } /** * Constructs a URL from this URI. * *

This convenience method works as if invoking it were equivalent to * evaluating the expression {@code new URL(this.toString())} after * first checking that this URI is absolute.

* * @return A URL constructed from this URI * * @throws IllegalArgumentException * If this URL is not absolute * * @throws MalformedURLException * If a protocol handler for the URL could not be found, * or if some other error occurred while constructing the URL */ public URL toURL() throws MalformedURLException { if (!isAbsolute()) throw new IllegalArgumentException("URI is not absolute"); return new URL(toString()); } // -- Component access methods -- /** * Returns the scheme component of this URI. * *

The scheme component of a URI, if defined, only contains characters * in the alphanum category and in the string {@code "-.+"}. A * scheme always starts with an alpha character.

* * The scheme component of a URI cannot contain escaped octets, hence this * method does not perform any decoding. * * @return The scheme component of this URI, * or {@code null} if the scheme is undefined */ public String getScheme() { return scheme; } /** * Tells whether or not this URI is absolute. * *

A URI is absolute if, and only if, it has a scheme component.

* * @return {@code true} if, and only if, this URI is absolute */ public boolean isAbsolute() { return scheme != null; } /** * Tells whether or not this URI is opaque. * *

A URI is opaque if, and only if, it is absolute and its * scheme-specific part does not begin with a slash character ('/'). * An opaque URI has a scheme, a scheme-specific part, and possibly * a fragment; all other components are undefined.

* * @return {@code true} if, and only if, this URI is opaque */ public boolean isOpaque() { return path == null; } /** * Returns the raw scheme-specific part of this URI. The scheme-specific * part is never undefined, though it may be empty. * *

The scheme-specific part of a URI only contains legal URI * characters.

* * @return The raw scheme-specific part of this URI * (never {@code null}) */ public String getRawSchemeSpecificPart() { defineSchemeSpecificPart(); return schemeSpecificPart; } /** * Returns the decoded scheme-specific part of this URI. * *

The string returned by this method is equal to that returned by the * {@link #getRawSchemeSpecificPart() getRawSchemeSpecificPart} method * except that all sequences of escaped octets are decoded.

* * @return The decoded scheme-specific part of this URI * (never {@code null}) */ public String getSchemeSpecificPart() { if (decodedSchemeSpecificPart == null) decodedSchemeSpecificPart = decode(getRawSchemeSpecificPart()); return decodedSchemeSpecificPart; } /** * Returns the raw authority component of this URI. * *

The authority component of a URI, if defined, only contains the * commercial-at character ({@code '@'}) and characters in the * unreserved, punct, escaped, and other * categories. If the authority is server-based then it is further * constrained to have valid user-information, host, and port * components.

* * @return The raw authority component of this URI, * or {@code null} if the authority is undefined */ public String getRawAuthority() { return authority; } /** * Returns the decoded authority component of this URI. * *

The string returned by this method is equal to that returned by the * {@link #getRawAuthority() getRawAuthority} method except that all * sequences of escaped octets are decoded.

* * @return The decoded authority component of this URI, * or {@code null} if the authority is undefined */ public String getAuthority() { if (decodedAuthority == null) decodedAuthority = decode(authority); return decodedAuthority; } /** * Returns the raw user-information component of this URI. * *

The user-information component of a URI, if defined, only contains * characters in the unreserved, punct, escaped, and * other categories.

* * @return The raw user-information component of this URI, * or {@code null} if the user information is undefined */ public String getRawUserInfo() { return userInfo; } /** * Returns the decoded user-information component of this URI. * *

The string returned by this method is equal to that returned by the * {@link #getRawUserInfo() getRawUserInfo} method except that all * sequences of escaped octets are decoded.

* * @return The decoded user-information component of this URI, * or {@code null} if the user information is undefined */ public String getUserInfo() { if ((decodedUserInfo == null) && (userInfo != null)) decodedUserInfo = decode(userInfo); return decodedUserInfo; } /** * Returns the host component of this URI. * *

The host component of a URI, if defined, will have one of the * following forms:

* * * * The host component of a URI cannot contain escaped octets, hence this * method does not perform any decoding. * * @return The host component of this URI, * or {@code null} if the host is undefined */ public String getHost() { return host; } /** * Returns the port number of this URI. * *

The port component of a URI, if defined, is a non-negative * integer.

* * @return The port component of this URI, * or {@code -1} if the port is undefined */ public int getPort() { return port; } /** * Returns the raw path component of this URI. * *

The path component of a URI, if defined, only contains the slash * character ({@code '/'}), the commercial-at character ({@code '@'}), * and characters in the unreserved, punct, escaped, * and other categories.

* * @return The path component of this URI, * or {@code null} if the path is undefined */ public String getRawPath() { return path; } /** * Returns the decoded path component of this URI. * *

The string returned by this method is equal to that returned by the * {@link #getRawPath() getRawPath} method except that all sequences of * escaped octets are decoded.

* * @return The decoded path component of this URI, * or {@code null} if the path is undefined */ public String getPath() { if ((decodedPath == null) && (path != null)) decodedPath = decode(path); return decodedPath; } /** * Returns the raw query component of this URI. * *

The query component of a URI, if defined, only contains legal URI * characters.

* * @return The raw query component of this URI, * or {@code null} if the query is undefined */ public String getRawQuery() { return query; } /** * Returns the decoded query component of this URI. * *

The string returned by this method is equal to that returned by the * {@link #getRawQuery() getRawQuery} method except that all sequences of * escaped octets are decoded.

* * @return The decoded query component of this URI, * or {@code null} if the query is undefined */ public String getQuery() { if ((decodedQuery == null) && (query != null)) decodedQuery = decode(query); return decodedQuery; } /** * Returns the raw fragment component of this URI. * *

The fragment component of a URI, if defined, only contains legal URI * characters.

* * @return The raw fragment component of this URI, * or {@code null} if the fragment is undefined */ public String getRawFragment() { return fragment; } /** * Returns the decoded fragment component of this URI. * *

The string returned by this method is equal to that returned by the * {@link #getRawFragment() getRawFragment} method except that all * sequences of escaped octets are decoded.

* * @return The decoded fragment component of this URI, * or {@code null} if the fragment is undefined */ public String getFragment() { if ((decodedFragment == null) && (fragment != null)) decodedFragment = decode(fragment); return decodedFragment; } // -- Equality, comparison, hash code, toString, and serialization -- /** * Tests this URI for equality with another object. * *

If the given object is not a URI then this method immediately * returns {@code false}. * *

For two URIs to be considered equal requires that either both are * opaque or both are hierarchical. Their schemes must either both be * undefined or else be equal without regard to case. Their fragments * must either both be undefined or else be equal. * *

For two opaque URIs to be considered equal, their scheme-specific * parts must be equal. * *

For two hierarchical URIs to be considered equal, their paths must * be equal and their queries must either both be undefined or else be * equal. Their authorities must either both be undefined, or both be * registry-based, or both be server-based. If their authorities are * defined and are registry-based, then they must be equal. If their * authorities are defined and are server-based, then their hosts must be * equal without regard to case, their port numbers must be equal, and * their user-information components must be equal. * *

When testing the user-information, path, query, fragment, authority, * or scheme-specific parts of two URIs for equality, the raw forms rather * than the encoded forms of these components are compared and the * hexadecimal digits of escaped octets are compared without regard to * case. * *

This method satisfies the general contract of the {@link * java.lang.Object#equals(Object) Object.equals} method.

* * @param ob The object to which this object is to be compared * * @return {@code true} if, and only if, the given object is a URI that * is identical to this URI */ public boolean equals(Object ob) { if (ob == this) return true; if (!(ob instanceof URI)) return false; URI that = (URI)ob; if (this.isOpaque() != that.isOpaque()) return false; if (!equalIgnoringCase(this.scheme, that.scheme)) return false; if (!equal(this.fragment, that.fragment)) return false; // Opaque if (this.isOpaque()) return equal(this.schemeSpecificPart, that.schemeSpecificPart); // Hierarchical if (!equal(this.path, that.path)) return false; if (!equal(this.query, that.query)) return false; // Authorities if (this.authority == that.authority) return true; if (this.host != null) { // Server-based if (!equal(this.userInfo, that.userInfo)) return false; if (!equalIgnoringCase(this.host, that.host)) return false; if (this.port != that.port) return false; } else if (this.authority != null) { // Registry-based if (!equal(this.authority, that.authority)) return false; } else if (this.authority != that.authority) { return false; } return true; } /** * Returns a hash-code value for this URI. The hash code is based upon all * of the URI's components, and satisfies the general contract of the * {@link java.lang.Object#hashCode() Object.hashCode} method. * * @return A hash-code value for this URI */ public int hashCode() { if (hash != 0) return hash; int h = hashIgnoringCase(0, scheme); h = hash(h, fragment); if (isOpaque()) { h = hash(h, schemeSpecificPart); } else { h = hash(h, path); h = hash(h, query); if (host != null) { h = hash(h, userInfo); h = hashIgnoringCase(h, host); h += 1949 * port; } else { h = hash(h, authority); } } hash = h; return h; } /** * Compares this URI to another object, which must be a URI. * *

When comparing corresponding components of two URIs, if one * component is undefined but the other is defined then the first is * considered to be less than the second. Unless otherwise noted, string * components are ordered according to their natural, case-sensitive * ordering as defined by the {@link java.lang.String#compareTo(Object) * String.compareTo} method. String components that are subject to * encoding are compared by comparing their raw forms rather than their * encoded forms. * *

The ordering of URIs is defined as follows:

* * * *

This method satisfies the general contract of the {@link * java.lang.Comparable#compareTo(Object) Comparable.compareTo} * method.

* * @param that * The object to which this URI is to be compared * * @return A negative integer, zero, or a positive integer as this URI is * less than, equal to, or greater than the given URI * * @throws ClassCastException * If the given object is not a URI */ public int compareTo(URI that) { int c; if ((c = compareIgnoringCase(this.scheme, that.scheme)) != 0) return c; if (this.isOpaque()) { if (that.isOpaque()) { // Both opaque if ((c = compare(this.schemeSpecificPart, that.schemeSpecificPart)) != 0) return c; return compare(this.fragment, that.fragment); } return +1; // Opaque > hierarchical } else if (that.isOpaque()) { return -1; // Hierarchical < opaque } // Hierarchical if ((this.host != null) && (that.host != null)) { // Both server-based if ((c = compare(this.userInfo, that.userInfo)) != 0) return c; if ((c = compareIgnoringCase(this.host, that.host)) != 0) return c; if ((c = this.port - that.port) != 0) return c; } else { // If one or both authorities are registry-based then we simply // compare them in the usual, case-sensitive way. If one is // registry-based and one is server-based then the strings are // guaranteed to be unequal, hence the comparison will never return // zero and the compareTo and equals methods will remain // consistent. if ((c = compare(this.authority, that.authority)) != 0) return c; } if ((c = compare(this.path, that.path)) != 0) return c; if ((c = compare(this.query, that.query)) != 0) return c; return compare(this.fragment, that.fragment); } /** * Returns the content of this URI as a string. * *

If this URI was created by invoking one of the constructors in this * class then a string equivalent to the original input string, or to the * string computed from the originally-given components, as appropriate, is * returned. Otherwise this URI was created by normalization, resolution, * or relativization, and so a string is constructed from this URI's * components according to the rules specified in RFC 2396, * section 5.2, step 7.

* * @return The string form of this URI */ public String toString() { defineString(); return string; } /** * Returns the content of this URI as a US-ASCII string. * *

If this URI does not contain any characters in the other * category then an invocation of this method will return the same value as * an invocation of the {@link #toString() toString} method. Otherwise * this method works as if by invoking that method and then encoding the result.

* * @return The string form of this URI, encoded as needed * so that it only contains characters in the US-ASCII * charset */ public String toASCIIString() { defineString(); return encode(string); } // -- Serialization support -- /** * Saves the content of this URI to the given serial stream. * *

The only serializable field of a URI instance is its {@code string} * field. That field is given a value, if it does not have one already, * and then the {@link java.io.ObjectOutputStream#defaultWriteObject()} * method of the given object-output stream is invoked.

* * @param os The object-output stream to which this object * is to be written */ private void writeObject(ObjectOutputStream os) throws IOException { defineString(); os.defaultWriteObject(); // Writes the string field only } /** * Reconstitutes a URI from the given serial stream. * *

The {@link java.io.ObjectInputStream#defaultReadObject()} method is * invoked to read the value of the {@code string} field. The result is * then parsed in the usual way. * * @param is The object-input stream from which this object * is being read */ private void readObject(ObjectInputStream is) throws ClassNotFoundException, IOException { port = -1; // Argh is.defaultReadObject(); try { new Parser(string).parse(false); } catch (URISyntaxException x) { IOException y = new InvalidObjectException("Invalid URI"); y.initCause(x); throw y; } } // -- End of public methods -- // -- Utility methods for string-field comparison and hashing -- // These methods return appropriate values for null string arguments, // thereby simplifying the equals, hashCode, and compareTo methods. // // The case-ignoring methods should only be applied to strings whose // characters are all known to be US-ASCII. Because of this restriction, // these methods are faster than the similar methods in the String class. // US-ASCII only private static int toLower(char c) { if ((c >= 'A') && (c <= 'Z')) return c + ('a' - 'A'); return c; } // US-ASCII only private static int toUpper(char c) { if ((c >= 'a') && (c <= 'z')) return c - ('a' - 'A'); return c; } private static boolean equal(String s, String t) { if (s == t) return true; if ((s != null) && (t != null)) { if (s.length() != t.length()) return false; if (s.indexOf('%') < 0) return s.equals(t); int n = s.length(); for (int i = 0; i < n;) { char c = s.charAt(i); char d = t.charAt(i); if (c != '%') { if (c != d) return false; i++; continue; } if (d != '%') return false; i++; if (toLower(s.charAt(i)) != toLower(t.charAt(i))) return false; i++; if (toLower(s.charAt(i)) != toLower(t.charAt(i))) return false; i++; } return true; } return false; } // US-ASCII only private static boolean equalIgnoringCase(String s, String t) { if (s == t) return true; if ((s != null) && (t != null)) { int n = s.length(); if (t.length() != n) return false; for (int i = 0; i < n; i++) { if (toLower(s.charAt(i)) != toLower(t.charAt(i))) return false; } return true; } return false; } private static int hash(int hash, String s) { if (s == null) return hash; return s.indexOf('%') < 0 ? hash * 127 + s.hashCode() : normalizedHash(hash, s); } private static int normalizedHash(int hash, String s) { int h = 0; for (int index = 0; index < s.length(); index++) { char ch = s.charAt(index); h = 31 * h + ch; if (ch == '%') { /* * Process the next two encoded characters */ for (int i = index + 1; i < index + 3; i++) h = 31 * h + toUpper(s.charAt(i)); index += 2; } } return hash * 127 + h; } // US-ASCII only private static int hashIgnoringCase(int hash, String s) { if (s == null) return hash; int h = hash; int n = s.length(); for (int i = 0; i < n; i++) h = 31 * h + toLower(s.charAt(i)); return h; } private static int compare(String s, String t) { if (s == t) return 0; if (s != null) { if (t != null) return s.compareTo(t); else return +1; } else { return -1; } } // US-ASCII only private static int compareIgnoringCase(String s, String t) { if (s == t) return 0; if (s != null) { if (t != null) { int sn = s.length(); int tn = t.length(); int n = sn < tn ? sn : tn; for (int i = 0; i < n; i++) { int c = toLower(s.charAt(i)) - toLower(t.charAt(i)); if (c != 0) return c; } return sn - tn; } return +1; } else { return -1; } } // -- String construction -- // If a scheme is given then the path, if given, must be absolute // private static void checkPath(String s, String scheme, String path) throws URISyntaxException { if (scheme != null) { if ((path != null) && ((path.length() > 0) && (path.charAt(0) != '/'))) throw new URISyntaxException(s, "Relative path in absolute URI"); } } private void appendAuthority(StringBuffer sb, String authority, String userInfo, String host, int port) { if (host != null) { sb.append("//"); if (userInfo != null) { sb.append(quote(userInfo, L_USERINFO, H_USERINFO)); sb.append('@'); } boolean needBrackets = ((host.indexOf(':') >= 0) && !host.startsWith("[") && !host.endsWith("]")); if (needBrackets) sb.append('['); sb.append(host); if (needBrackets) sb.append(']'); if (port != -1) { sb.append(':'); sb.append(port); } } else if (authority != null) { sb.append("//"); if (authority.startsWith("[")) { // authority should (but may not) contain an embedded IPv6 address int end = authority.indexOf("]"); String doquote = authority, dontquote = ""; if (end != -1 && authority.indexOf(":") != -1) { // the authority contains an IPv6 address if (end == authority.length()) { dontquote = authority; doquote = ""; } else { dontquote = authority.substring(0 , end + 1); doquote = authority.substring(end + 1); } } sb.append(dontquote); sb.append(quote(doquote, L_REG_NAME | L_SERVER, H_REG_NAME | H_SERVER)); } else { sb.append(quote(authority, L_REG_NAME | L_SERVER, H_REG_NAME | H_SERVER)); } } } private void appendSchemeSpecificPart(StringBuffer sb, String opaquePart, String authority, String userInfo, String host, int port, String path, String query) { if (opaquePart != null) { /* check if SSP begins with an IPv6 address * because we must not quote a literal IPv6 address */ if (opaquePart.startsWith("//[")) { int end = opaquePart.indexOf("]"); if (end != -1 && opaquePart.indexOf(":")!=-1) { String doquote, dontquote; if (end == opaquePart.length()) { dontquote = opaquePart; doquote = ""; } else { dontquote = opaquePart.substring(0,end+1); doquote = opaquePart.substring(end+1); } sb.append (dontquote); sb.append(quote(doquote, L_URIC, H_URIC)); } } else { sb.append(quote(opaquePart, L_URIC, H_URIC)); } } else { appendAuthority(sb, authority, userInfo, host, port); if (path != null) sb.append(quote(path, L_PATH, H_PATH)); if (query != null) { sb.append('?'); sb.append(quote(query, L_URIC, H_URIC)); } } } private void appendFragment(StringBuffer sb, String fragment) { if (fragment != null) { sb.append('#'); sb.append(quote(fragment, L_URIC, H_URIC)); } } private String toString(String scheme, String opaquePart, String authority, String userInfo, String host, int port, String path, String query, String fragment) { StringBuffer sb = new StringBuffer(); if (scheme != null) { sb.append(scheme); sb.append(':'); } appendSchemeSpecificPart(sb, opaquePart, authority, userInfo, host, port, path, query); appendFragment(sb, fragment); return sb.toString(); } private void defineSchemeSpecificPart() { if (schemeSpecificPart != null) return; StringBuffer sb = new StringBuffer(); appendSchemeSpecificPart(sb, null, getAuthority(), getUserInfo(), host, port, getPath(), getQuery()); if (sb.length() == 0) return; schemeSpecificPart = sb.toString(); } private void defineString() { if (string != null) return; StringBuffer sb = new StringBuffer(); if (scheme != null) { sb.append(scheme); sb.append(':'); } if (isOpaque()) { sb.append(schemeSpecificPart); } else { if (host != null) { sb.append("//"); if (userInfo != null) { sb.append(userInfo); sb.append('@'); } boolean needBrackets = ((host.indexOf(':') >= 0) && !host.startsWith("[") && !host.endsWith("]")); if (needBrackets) sb.append('['); sb.append(host); if (needBrackets) sb.append(']'); if (port != -1) { sb.append(':'); sb.append(port); } } else if (authority != null) { sb.append("//"); sb.append(authority); } if (path != null) sb.append(path); if (query != null) { sb.append('?'); sb.append(query); } } if (fragment != null) { sb.append('#'); sb.append(fragment); } string = sb.toString(); } // -- Normalization, resolution, and relativization -- // RFC2396 5.2 (6) private static String resolvePath(String base, String child, boolean absolute) { int i = base.lastIndexOf('/'); int cn = child.length(); String path = ""; if (cn == 0) { // 5.2 (6a) if (i >= 0) path = base.substring(0, i + 1); } else { StringBuffer sb = new StringBuffer(base.length() + cn); // 5.2 (6a) if (i >= 0) sb.append(base.substring(0, i + 1)); // 5.2 (6b) sb.append(child); path = sb.toString(); } // 5.2 (6c-f) String np = normalize(path); // 5.2 (6g): If the result is absolute but the path begins with "../", // then we simply leave the path as-is return np; } // RFC2396 5.2 private static URI resolve(URI base, URI child) { // check if child if opaque first so that NPE is thrown // if child is null. if (child.isOpaque() || base.isOpaque()) return child; // 5.2 (2): Reference to current document (lone fragment) if ((child.scheme == null) && (child.authority == null) && child.path.equals("") && (child.fragment != null) && (child.query == null)) { if ((base.fragment != null) && child.fragment.equals(base.fragment)) { return base; } URI ru = new URI(); ru.scheme = base.scheme; ru.authority = base.authority; ru.userInfo = base.userInfo; ru.host = base.host; ru.port = base.port; ru.path = base.path; ru.fragment = child.fragment; ru.query = base.query; return ru; } // 5.2 (3): Child is absolute if (child.scheme != null) return child; URI ru = new URI(); // Resolved URI ru.scheme = base.scheme; ru.query = child.query; ru.fragment = child.fragment; // 5.2 (4): Authority if (child.authority == null) { ru.authority = base.authority; ru.host = base.host; ru.userInfo = base.userInfo; ru.port = base.port; String cp = (child.path == null) ? "" : child.path; if ((cp.length() > 0) && (cp.charAt(0) == '/')) { // 5.2 (5): Child path is absolute ru.path = child.path; } else { // 5.2 (6): Resolve relative path ru.path = resolvePath(base.path, cp, base.isAbsolute()); } } else { ru.authority = child.authority; ru.host = child.host; ru.userInfo = child.userInfo; ru.host = child.host; ru.port = child.port; ru.path = child.path; } // 5.2 (7): Recombine (nothing to do here) return ru; } // If the given URI's path is normal then return the URI; // o.w., return a new URI containing the normalized path. // private static URI normalize(URI u) { if (u.isOpaque() || (u.path == null) || (u.path.length() == 0)) return u; String np = normalize(u.path); if (np == u.path) return u; URI v = new URI(); v.scheme = u.scheme; v.fragment = u.fragment; v.authority = u.authority; v.userInfo = u.userInfo; v.host = u.host; v.port = u.port; v.path = np; v.query = u.query; return v; } // If both URIs are hierarchical, their scheme and authority components are // identical, and the base path is a prefix of the child's path, then // return a relative URI that, when resolved against the base, yields the // child; otherwise, return the child. // private static URI relativize(URI base, URI child) { // check if child if opaque first so that NPE is thrown // if child is null. if (child.isOpaque() || base.isOpaque()) return child; if (!equalIgnoringCase(base.scheme, child.scheme) || !equal(base.authority, child.authority)) return child; String bp = normalize(base.path); String cp = normalize(child.path); if (!bp.equals(cp)) { if (!bp.endsWith("/")) bp = bp + "/"; if (!cp.startsWith(bp)) return child; } URI v = new URI(); v.path = cp.substring(bp.length()); v.query = child.query; v.fragment = child.fragment; return v; } // -- Path normalization -- // The following algorithm for path normalization avoids the creation of a // string object for each segment, as well as the use of a string buffer to // compute the final result, by using a single char array and editing it in // place. The array is first split into segments, replacing each slash // with '\0' and creating a segment-index array, each element of which is // the index of the first char in the corresponding segment. We then walk // through both arrays, removing ".", "..", and other segments as necessary // by setting their entries in the index array to -1. Finally, the two // arrays are used to rejoin the segments and compute the final result. // // This code is based upon src/solaris/native/java/io/canonicalize_md.c // Check the given path to see if it might need normalization. A path // might need normalization if it contains duplicate slashes, a "." // segment, or a ".." segment. Return -1 if no further normalization is // possible, otherwise return the number of segments found. // // This method takes a string argument rather than a char array so that // this test can be performed without invoking path.toCharArray(). // static private int needsNormalization(String path) { boolean normal = true; int ns = 0; // Number of segments int end = path.length() - 1; // Index of last char in path int p = 0; // Index of next char in path // Skip initial slashes while (p <= end) { if (path.charAt(p) != '/') break; p++; } if (p > 1) normal = false; // Scan segments while (p <= end) { // Looking at "." or ".." ? if ((path.charAt(p) == '.') && ((p == end) || ((path.charAt(p + 1) == '/') || ((path.charAt(p + 1) == '.') && ((p + 1 == end) || (path.charAt(p + 2) == '/')))))) { normal = false; } ns++; // Find beginning of next segment while (p <= end) { if (path.charAt(p++) != '/') continue; // Skip redundant slashes while (p <= end) { if (path.charAt(p) != '/') break; normal = false; p++; } break; } } return normal ? -1 : ns; } // Split the given path into segments, replacing slashes with nulls and // filling in the given segment-index array. // // Preconditions: // segs.length == Number of segments in path // // Postconditions: // All slashes in path replaced by '\0' // segs[i] == Index of first char in segment i (0 <= i < segs.length) // static private void split(char[] path, int[] segs) { int end = path.length - 1; // Index of last char in path int p = 0; // Index of next char in path int i = 0; // Index of current segment // Skip initial slashes while (p <= end) { if (path[p] != '/') break; path[p] = '\0'; p++; } while (p <= end) { // Note start of segment segs[i++] = p++; // Find beginning of next segment while (p <= end) { if (path[p++] != '/') continue; path[p - 1] = '\0'; // Skip redundant slashes while (p <= end) { if (path[p] != '/') break; path[p++] = '\0'; } break; } } if (i != segs.length) throw new InternalError(); // ASSERT } // Join the segments in the given path according to the given segment-index // array, ignoring those segments whose index entries have been set to -1, // and inserting slashes as needed. Return the length of the resulting // path. // // Preconditions: // segs[i] == -1 implies segment i is to be ignored // path computed by split, as above, with '\0' having replaced '/' // // Postconditions: // path[0] .. path[return value] == Resulting path // static private int join(char[] path, int[] segs) { int ns = segs.length; // Number of segments int end = path.length - 1; // Index of last char in path int p = 0; // Index of next path char to write if (path[p] == '\0') { // Restore initial slash for absolute paths path[p++] = '/'; } for (int i = 0; i < ns; i++) { int q = segs[i]; // Current segment if (q == -1) // Ignore this segment continue; if (p == q) { // We're already at this segment, so just skip to its end while ((p <= end) && (path[p] != '\0')) p++; if (p <= end) { // Preserve trailing slash path[p++] = '/'; } } else if (p < q) { // Copy q down to p while ((q <= end) && (path[q] != '\0')) path[p++] = path[q++]; if (q <= end) { // Preserve trailing slash path[p++] = '/'; } } else throw new InternalError(); // ASSERT false } return p; } // Remove "." segments from the given path, and remove segment pairs // consisting of a non-".." segment followed by a ".." segment. // private static void removeDots(char[] path, int[] segs) { int ns = segs.length; int end = path.length - 1; for (int i = 0; i < ns; i++) { int dots = 0; // Number of dots found (0, 1, or 2) // Find next occurrence of "." or ".." do { int p = segs[i]; if (path[p] == '.') { if (p == end) { dots = 1; break; } else if (path[p + 1] == '\0') { dots = 1; break; } else if ((path[p + 1] == '.') && ((p + 1 == end) || (path[p + 2] == '\0'))) { dots = 2; break; } } i++; } while (i < ns); if ((i > ns) || (dots == 0)) break; if (dots == 1) { // Remove this occurrence of "." segs[i] = -1; } else { // If there is a preceding non-".." segment, remove both that // segment and this occurrence of ".."; otherwise, leave this // ".." segment as-is. int j; for (j = i - 1; j >= 0; j--) { if (segs[j] != -1) break; } if (j >= 0) { int q = segs[j]; if (!((path[q] == '.') && (path[q + 1] == '.') && (path[q + 2] == '\0'))) { segs[i] = -1; segs[j] = -1; } } } } } // DEVIATION: If the normalized path is relative, and if the first // segment could be parsed as a scheme name, then prepend a "." segment // private static void maybeAddLeadingDot(char[] path, int[] segs) { if (path[0] == '\0') // The path is absolute return; int ns = segs.length; int f = 0; // Index of first segment while (f < ns) { if (segs[f] >= 0) break; f++; } if ((f >= ns) || (f == 0)) // The path is empty, or else the original first segment survived, // in which case we already know that no leading "." is needed return; int p = segs[f]; while ((p < path.length) && (path[p] != ':') && (path[p] != '\0')) p++; if (p >= path.length || path[p] == '\0') // No colon in first segment, so no "." needed return; // At this point we know that the first segment is unused, // hence we can insert a "." segment at that position path[0] = '.'; path[1] = '\0'; segs[0] = 0; } // Normalize the given path string. A normal path string has no empty // segments (i.e., occurrences of "//"), no segments equal to ".", and no // segments equal to ".." that are preceded by a segment not equal to "..". // In contrast to Unix-style pathname normalization, for URI paths we // always retain trailing slashes. // private static String normalize(String ps) { // Does this path need normalization? int ns = needsNormalization(ps); // Number of segments if (ns < 0) // Nope -- just return it return ps; char[] path = ps.toCharArray(); // Path in char-array form // Split path into segments int[] segs = new int[ns]; // Segment-index array split(path, segs); // Remove dots removeDots(path, segs); // Prevent scheme-name confusion maybeAddLeadingDot(path, segs); // Join the remaining segments and return the result String s = new String(path, 0, join(path, segs)); if (s.equals(ps)) { // string was already normalized return ps; } return s; } // -- Character classes for parsing -- // RFC2396 precisely specifies which characters in the US-ASCII charset are // permissible in the various components of a URI reference. We here // define a set of mask pairs to aid in enforcing these restrictions. Each // mask pair consists of two longs, a low mask and a high mask. Taken // together they represent a 128-bit mask, where bit i is set iff the // character with value i is permitted. // // This approach is more efficient than sequentially searching arrays of // permitted characters. It could be made still more efficient by // precompiling the mask information so that a character's presence in a // given mask could be determined by a single table lookup. // Compute the low-order mask for the characters in the given string private static long lowMask(String chars) { int n = chars.length(); long m = 0; for (int i = 0; i < n; i++) { char c = chars.charAt(i); if (c < 64) m |= (1L << c); } return m; } // Compute the high-order mask for the characters in the given string private static long highMask(String chars) { int n = chars.length(); long m = 0; for (int i = 0; i < n; i++) { char c = chars.charAt(i); if ((c >= 64) && (c < 128)) m |= (1L << (c - 64)); } return m; } // Compute a low-order mask for the characters // between first and last, inclusive private static long lowMask(char first, char last) { long m = 0; int f = Math.max(Math.min(first, 63), 0); int l = Math.max(Math.min(last, 63), 0); for (int i = f; i <= l; i++) m |= 1L << i; return m; } // Compute a high-order mask for the characters // between first and last, inclusive private static long highMask(char first, char last) { long m = 0; int f = Math.max(Math.min(first, 127), 64) - 64; int l = Math.max(Math.min(last, 127), 64) - 64; for (int i = f; i <= l; i++) m |= 1L << i; return m; } // Tell whether the given character is permitted by the given mask pair private static boolean match(char c, long lowMask, long highMask) { if (c == 0) // 0 doesn't have a slot in the mask. So, it never matches. return false; if (c < 64) return ((1L << c) & lowMask) != 0; if (c < 128) return ((1L << (c - 64)) & highMask) != 0; return false; } // Character-class masks, in reverse order from RFC2396 because // initializers for static fields cannot make forward references. // digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | // "8" | "9" private static final long L_DIGIT = lowMask('0', '9'); private static final long H_DIGIT = 0L; // upalpha = "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" | // "J" | "K" | "L" | "M" | "N" | "O" | "P" | "Q" | "R" | // "S" | "T" | "U" | "V" | "W" | "X" | "Y" | "Z" private static final long L_UPALPHA = 0L; private static final long H_UPALPHA = highMask('A', 'Z'); // lowalpha = "a" | "b" | "c" | "d" | "e" | "f" | "g" | "h" | "i" | // "j" | "k" | "l" | "m" | "n" | "o" | "p" | "q" | "r" | // "s" | "t" | "u" | "v" | "w" | "x" | "y" | "z" private static final long L_LOWALPHA = 0L; private static final long H_LOWALPHA = highMask('a', 'z'); // alpha = lowalpha | upalpha private static final long L_ALPHA = L_LOWALPHA | L_UPALPHA; private static final long H_ALPHA = H_LOWALPHA | H_UPALPHA; // alphanum = alpha | digit private static final long L_ALPHANUM = L_DIGIT | L_ALPHA; private static final long H_ALPHANUM = H_DIGIT | H_ALPHA; // hex = digit | "A" | "B" | "C" | "D" | "E" | "F" | // "a" | "b" | "c" | "d" | "e" | "f" private static final long L_HEX = L_DIGIT; private static final long H_HEX = highMask('A', 'F') | highMask('a', 'f'); // mark = "-" | "_" | "." | "!" | "~" | "*" | "'" | // "(" | ")" private static final long L_MARK = lowMask("-_.!~*'()"); private static final long H_MARK = highMask("-_.!~*'()"); // unreserved = alphanum | mark private static final long L_UNRESERVED = L_ALPHANUM | L_MARK; private static final long H_UNRESERVED = H_ALPHANUM | H_MARK; // reserved = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" | // "$" | "," | "[" | "]" // Added per RFC2732: "[", "]" private static final long L_RESERVED = lowMask(";/?:@&=+$,[]"); private static final long H_RESERVED = highMask(";/?:@&=+$,[]"); // The zero'th bit is used to indicate that escape pairs and non-US-ASCII // characters are allowed; this is handled by the scanEscape method below. private static final long L_ESCAPED = 1L; private static final long H_ESCAPED = 0L; // uric = reserved | unreserved | escaped private static final long L_URIC = L_RESERVED | L_UNRESERVED | L_ESCAPED; private static final long H_URIC = H_RESERVED | H_UNRESERVED | H_ESCAPED; // pchar = unreserved | escaped | // ":" | "@" | "&" | "=" | "+" | "$" | "," private static final long L_PCHAR = L_UNRESERVED | L_ESCAPED | lowMask(":@&=+$,"); private static final long H_PCHAR = H_UNRESERVED | H_ESCAPED | highMask(":@&=+$,"); // All valid path characters private static final long L_PATH = L_PCHAR | lowMask(";/"); private static final long H_PATH = H_PCHAR | highMask(";/"); // Dash, for use in domainlabel and toplabel private static final long L_DASH = lowMask("-"); private static final long H_DASH = highMask("-"); // Dot, for use in hostnames private static final long L_DOT = lowMask("."); private static final long H_DOT = highMask("."); // userinfo = *( unreserved | escaped | // ";" | ":" | "&" | "=" | "+" | "$" | "," ) private static final long L_USERINFO = L_UNRESERVED | L_ESCAPED | lowMask(";:&=+$,"); private static final long H_USERINFO = H_UNRESERVED | H_ESCAPED | highMask(";:&=+$,"); // reg_name = 1*( unreserved | escaped | "$" | "," | // ";" | ":" | "@" | "&" | "=" | "+" ) private static final long L_REG_NAME = L_UNRESERVED | L_ESCAPED | lowMask("$,;:@&=+"); private static final long H_REG_NAME = H_UNRESERVED | H_ESCAPED | highMask("$,;:@&=+"); // All valid characters for server-based authorities private static final long L_SERVER = L_USERINFO | L_ALPHANUM | L_DASH | lowMask(".:@[]"); private static final long H_SERVER = H_USERINFO | H_ALPHANUM | H_DASH | highMask(".:@[]"); // Special case of server authority that represents an IPv6 address // In this case, a % does not signify an escape sequence private static final long L_SERVER_PERCENT = L_SERVER | lowMask("%"); private static final long H_SERVER_PERCENT = H_SERVER | highMask("%"); private static final long L_LEFT_BRACKET = lowMask("["); private static final long H_LEFT_BRACKET = highMask("["); // scheme = alpha *( alpha | digit | "+" | "-" | "." ) private static final long L_SCHEME = L_ALPHA | L_DIGIT | lowMask("+-."); private static final long H_SCHEME = H_ALPHA | H_DIGIT | highMask("+-."); // uric_no_slash = unreserved | escaped | ";" | "?" | ":" | "@" | // "&" | "=" | "+" | "$" | "," private static final long L_URIC_NO_SLASH = L_UNRESERVED | L_ESCAPED | lowMask(";?:@&=+$,"); private static final long H_URIC_NO_SLASH = H_UNRESERVED | H_ESCAPED | highMask(";?:@&=+$,"); // -- Escaping and encoding -- private final static char[] hexDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' }; private static void appendEscape(StringBuffer sb, byte b) { sb.append('%'); sb.append(hexDigits[(b >> 4) & 0x0f]); sb.append(hexDigits[(b >> 0) & 0x0f]); } private static void appendEncoded(StringBuffer sb, char c) { ByteBuffer bb = null; try { bb = ThreadLocalCoders.encoderFor("UTF-8") .encode(CharBuffer.wrap("" + c)); } catch (CharacterCodingException x) { assert false; } while (bb.hasRemaining()) { int b = bb.get() & 0xff; if (b >= 0x80) appendEscape(sb, (byte)b); else sb.append((char)b); } } // Quote any characters in s that are not permitted // by the given mask pair // private static String quote(String s, long lowMask, long highMask) { int n = s.length(); StringBuffer sb = null; boolean allowNonASCII = ((lowMask & L_ESCAPED) != 0); for (int i = 0; i < s.length(); i++) { char c = s.charAt(i); if (c < '\u0080') { if (!match(c, lowMask, highMask)) { if (sb == null) { sb = new StringBuffer(); sb.append(s.substring(0, i)); } appendEscape(sb, (byte)c); } else { if (sb != null) sb.append(c); } } else if (allowNonASCII && (Character.isSpaceChar(c) || Character.isISOControl(c))) { if (sb == null) { sb = new StringBuffer(); sb.append(s.substring(0, i)); } appendEncoded(sb, c); } else { if (sb != null) sb.append(c); } } return (sb == null) ? s : sb.toString(); } // Encodes all characters >= \u0080 into escaped, normalized UTF-8 octets, // assuming that s is otherwise legal // private static String encode(String s) { int n = s.length(); if (n == 0) return s; // First check whether we actually need to encode for (int i = 0;;) { if (s.charAt(i) >= '\u0080') break; if (++i >= n) return s; } String ns = Normalizer.normalize(s, Normalizer.Form.NFC); ByteBuffer bb = null; try { bb = ThreadLocalCoders.encoderFor("UTF-8") .encode(CharBuffer.wrap(ns)); } catch (CharacterCodingException x) { assert false; } StringBuffer sb = new StringBuffer(); while (bb.hasRemaining()) { int b = bb.get() & 0xff; if (b >= 0x80) appendEscape(sb, (byte)b); else sb.append((char)b); } return sb.toString(); } private static int decode(char c) { if ((c >= '0') && (c <= '9')) return c - '0'; if ((c >= 'a') && (c <= 'f')) return c - 'a' + 10; if ((c >= 'A') && (c <= 'F')) return c - 'A' + 10; assert false; return -1; } private static byte decode(char c1, char c2) { return (byte)( ((decode(c1) & 0xf) << 4) | ((decode(c2) & 0xf) << 0)); } // Evaluates all escapes in s, applying UTF-8 decoding if needed. Assumes // that escapes are well-formed syntactically, i.e., of the form %XX. If a // sequence of escaped octets is not valid UTF-8 then the erroneous octets // are replaced with '\uFFFD'. // Exception: any "%" found between "[]" is left alone. It is an IPv6 literal // with a scope_id // private static String decode(String s) { if (s == null) return s; int n = s.length(); if (n == 0) return s; if (s.indexOf('%') < 0) return s; StringBuffer sb = new StringBuffer(n); ByteBuffer bb = ByteBuffer.allocate(n); CharBuffer cb = CharBuffer.allocate(n); CharsetDecoder dec = ThreadLocalCoders.decoderFor("UTF-8") .onMalformedInput(CodingErrorAction.REPLACE) .onUnmappableCharacter(CodingErrorAction.REPLACE); // This is not horribly efficient, but it will do for now char c = s.charAt(0); boolean betweenBrackets = false; for (int i = 0; i < n;) { assert c == s.charAt(i); // Loop invariant if (c == '[') { betweenBrackets = true; } else if (betweenBrackets && c == ']') { betweenBrackets = false; } if (c != '%' || betweenBrackets) { sb.append(c); if (++i >= n) break; c = s.charAt(i); continue; } bb.clear(); int ui = i; for (;;) { assert (n - i >= 2); bb.put(decode(s.charAt(++i), s.charAt(++i))); if (++i >= n) break; c = s.charAt(i); if (c != '%') break; } bb.flip(); cb.clear(); dec.reset(); CoderResult cr = dec.decode(bb, cb, true); assert cr.isUnderflow(); cr = dec.flush(cb); assert cr.isUnderflow(); sb.append(cb.flip().toString()); } return sb.toString(); } // -- Parsing -- // For convenience we wrap the input URI string in a new instance of the // following internal class. This saves always having to pass the input // string as an argument to each internal scan/parse method. private class Parser { private String input; // URI input string private boolean requireServerAuthority = false; Parser(String s) { input = s; string = s; } // -- Methods for throwing URISyntaxException in various ways -- private void fail(String reason) throws URISyntaxException { throw new URISyntaxException(input, reason); } private void fail(String reason, int p) throws URISyntaxException { throw new URISyntaxException(input, reason, p); } private void failExpecting(String expected, int p) throws URISyntaxException { fail("Expected " + expected, p); } private void failExpecting(String expected, String prior, int p) throws URISyntaxException { fail("Expected " + expected + " following " + prior, p); } // -- Simple access to the input string -- // Return a substring of the input string // private String substring(int start, int end) { return input.substring(start, end); } // Return the char at position p, // assuming that p < input.length() // private char charAt(int p) { return input.charAt(p); } // Tells whether start < end and, if so, whether charAt(start) == c // private boolean at(int start, int end, char c) { return (start < end) && (charAt(start) == c); } // Tells whether start + s.length() < end and, if so, // whether the chars at the start position match s exactly // private boolean at(int start, int end, String s) { int p = start; int sn = s.length(); if (sn > end - p) return false; int i = 0; while (i < sn) { if (charAt(p++) != s.charAt(i)) { break; } i++; } return (i == sn); } // -- Scanning -- // The various scan and parse methods that follow use a uniform // convention of taking the current start position and end index as // their first two arguments. The start is inclusive while the end is // exclusive, just as in the String class, i.e., a start/end pair // denotes the left-open interval [start, end) of the input string. // // These methods never proceed past the end position. They may return // -1 to indicate outright failure, but more often they simply return // the position of the first char after the last char scanned. Thus // a typical idiom is // // int p = start; // int q = scan(p, end, ...); // if (q > p) // // We scanned something // ...; // else if (q == p) // // We scanned nothing // ...; // else if (q == -1) // // Something went wrong // ...; // Scan a specific char: If the char at the given start position is // equal to c, return the index of the next char; otherwise, return the // start position. // private int scan(int start, int end, char c) { if ((start < end) && (charAt(start) == c)) return start + 1; return start; } // Scan forward from the given start position. Stop at the first char // in the err string (in which case -1 is returned), or the first char // in the stop string (in which case the index of the preceding char is // returned), or the end of the input string (in which case the length // of the input string is returned). May return the start position if // nothing matches. // private int scan(int start, int end, String err, String stop) { int p = start; while (p < end) { char c = charAt(p); if (err.indexOf(c) >= 0) return -1; if (stop.indexOf(c) >= 0) break; p++; } return p; } // Scan a potential escape sequence, starting at the given position, // with the given first char (i.e., charAt(start) == c). // // This method assumes that if escapes are allowed then visible // non-US-ASCII chars are also allowed. // private int scanEscape(int start, int n, char first) throws URISyntaxException { int p = start; char c = first; if (c == '%') { // Process escape pair if ((p + 3 <= n) && match(charAt(p + 1), L_HEX, H_HEX) && match(charAt(p + 2), L_HEX, H_HEX)) { return p + 3; } fail("Malformed escape pair", p); } else if ((c > 128) && !Character.isSpaceChar(c) && !Character.isISOControl(c)) { // Allow unescaped but visible non-US-ASCII chars return p + 1; } return p; } // Scan chars that match the given mask pair // private int scan(int start, int n, long lowMask, long highMask) throws URISyntaxException { int p = start; while (p < n) { char c = charAt(p); if (match(c, lowMask, highMask)) { p++; continue; } if ((lowMask & L_ESCAPED) != 0) { int q = scanEscape(p, n, c); if (q > p) { p = q; continue; } } break; } return p; } // Check that each of the chars in [start, end) matches the given mask // private void checkChars(int start, int end, long lowMask, long highMask, String what) throws URISyntaxException { int p = scan(start, end, lowMask, highMask); if (p < end) fail("Illegal character in " + what, p); } // Check that the char at position p matches the given mask // private void checkChar(int p, long lowMask, long highMask, String what) throws URISyntaxException { checkChars(p, p + 1, lowMask, highMask, what); } // -- Parsing -- // [:][#] // void parse(boolean rsa) throws URISyntaxException { requireServerAuthority = rsa; int ssp; // Start of scheme-specific part int n = input.length(); int p = scan(0, n, "/?#", ":"); if ((p >= 0) && at(p, n, ':')) { if (p == 0) failExpecting("scheme name", 0); checkChar(0, L_ALPHA, H_ALPHA, "scheme name"); checkChars(1, p, L_SCHEME, H_SCHEME, "scheme name"); scheme = substring(0, p); p++; // Skip ':' ssp = p; if (at(p, n, '/')) { p = parseHierarchical(p, n); } else { int q = scan(p, n, "", "#"); if (q <= p) failExpecting("scheme-specific part", p); checkChars(p, q, L_URIC, H_URIC, "opaque part"); p = q; } } else { ssp = 0; p = parseHierarchical(0, n); } schemeSpecificPart = substring(ssp, p); if (at(p, n, '#')) { checkChars(p + 1, n, L_URIC, H_URIC, "fragment"); fragment = substring(p + 1, n); p = n; } if (p < n) fail("end of URI", p); } // [//authority][?] // // DEVIATION from RFC2396: We allow an empty authority component as // long as it's followed by a non-empty path, query component, or // fragment component. This is so that URIs such as "file:///foo/bar" // will parse. This seems to be the intent of RFC2396, though the // grammar does not permit it. If the authority is empty then the // userInfo, host, and port components are undefined. // // DEVIATION from RFC2396: We allow empty relative paths. This seems // to be the intent of RFC2396, but the grammar does not permit it. // The primary consequence of this deviation is that "#f" parses as a // relative URI with an empty path. // private int parseHierarchical(int start, int n) throws URISyntaxException { int p = start; if (at(p, n, '/') && at(p + 1, n, '/')) { p += 2; int q = scan(p, n, "", "/?#"); if (q > p) { p = parseAuthority(p, q); } else if (q < n) { // DEVIATION: Allow empty authority prior to non-empty // path, query component or fragment identifier } else failExpecting("authority", p); } int q = scan(p, n, "", "?#"); // DEVIATION: May be empty checkChars(p, q, L_PATH, H_PATH, "path"); path = substring(p, q); p = q; if (at(p, n, '?')) { p++; q = scan(p, n, "", "#"); checkChars(p, q, L_URIC, H_URIC, "query"); query = substring(p, q); p = q; } return p; } // authority = server | reg_name // // Ambiguity: An authority that is a registry name rather than a server // might have a prefix that parses as a server. We use the fact that // the authority component is always followed by '/' or the end of the // input string to resolve this: If the complete authority did not // parse as a server then we try to parse it as a registry name. // private int parseAuthority(int start, int n) throws URISyntaxException { int p = start; int q = p; URISyntaxException ex = null; boolean serverChars; boolean regChars; if (scan(p, n, "", "]") > p) { // contains a literal IPv6 address, therefore % is allowed serverChars = (scan(p, n, L_SERVER_PERCENT, H_SERVER_PERCENT) == n); } else { serverChars = (scan(p, n, L_SERVER, H_SERVER) == n); } regChars = (scan(p, n, L_REG_NAME, H_REG_NAME) == n); if (regChars && !serverChars) { // Must be a registry-based authority authority = substring(p, n); return n; } if (serverChars) { // Might be (probably is) a server-based authority, so attempt // to parse it as such. If the attempt fails, try to treat it // as a registry-based authority. try { q = parseServer(p, n); if (q < n) failExpecting("end of authority", q); authority = substring(p, n); } catch (URISyntaxException x) { // Undo results of failed parse userInfo = null; host = null; port = -1; if (requireServerAuthority) { // If we're insisting upon a server-based authority, // then just re-throw the exception throw x; } else { // Save the exception in case it doesn't parse as a // registry either ex = x; q = p; } } } if (q < n) { if (regChars) { // Registry-based authority authority = substring(p, n); } else if (ex != null) { // Re-throw exception; it was probably due to // a malformed IPv6 address throw ex; } else { fail("Illegal character in authority", q); } } return n; } // [@][:] // private int parseServer(int start, int n) throws URISyntaxException { int p = start; int q; // userinfo q = scan(p, n, "/?#", "@"); if ((q >= p) && at(q, n, '@')) { checkChars(p, q, L_USERINFO, H_USERINFO, "user info"); userInfo = substring(p, q); p = q + 1; // Skip '@' } // hostname, IPv4 address, or IPv6 address if (at(p, n, '[')) { // DEVIATION from RFC2396: Support IPv6 addresses, per RFC2732 p++; q = scan(p, n, "/?#", "]"); if ((q > p) && at(q, n, ']')) { // look for a "%" scope id int r = scan (p, q, "", "%"); if (r > p) { parseIPv6Reference(p, r); if (r+1 == q) { fail ("scope id expected"); } checkChars (r+1, q, L_ALPHANUM, H_ALPHANUM, "scope id"); } else { parseIPv6Reference(p, q); } host = substring(p-1, q+1); p = q + 1; } else { failExpecting("closing bracket for IPv6 address", q); } } else { q = parseIPv4Address(p, n); if (q <= p) q = parseHostname(p, n); p = q; } // port if (at(p, n, ':')) { p++; q = scan(p, n, "", "/"); if (q > p) { checkChars(p, q, L_DIGIT, H_DIGIT, "port number"); try { port = Integer.parseInt(substring(p, q)); } catch (NumberFormatException x) { fail("Malformed port number", p); } p = q; } } if (p < n) failExpecting("port number", p); return p; } // Scan a string of decimal digits whose value fits in a byte // private int scanByte(int start, int n) throws URISyntaxException { int p = start; int q = scan(p, n, L_DIGIT, H_DIGIT); if (q <= p) return q; if (Integer.parseInt(substring(p, q)) > 255) return p; return q; } // Scan an IPv4 address. // // If the strict argument is true then we require that the given // interval contain nothing besides an IPv4 address; if it is false // then we only require that it start with an IPv4 address. // // If the interval does not contain or start with (depending upon the // strict argument) a legal IPv4 address characters then we return -1 // immediately; otherwise we insist that these characters parse as a // legal IPv4 address and throw an exception on failure. // // We assume that any string of decimal digits and dots must be an IPv4 // address. It won't parse as a hostname anyway, so making that // assumption here allows more meaningful exceptions to be thrown. // private int scanIPv4Address(int start, int n, boolean strict) throws URISyntaxException { int p = start; int q; int m = scan(p, n, L_DIGIT | L_DOT, H_DIGIT | H_DOT); if ((m <= p) || (strict && (m != n))) return -1; for (;;) { // Per RFC2732: At most three digits per byte // Further constraint: Each element fits in a byte if ((q = scanByte(p, m)) <= p) break; p = q; if ((q = scan(p, m, '.')) <= p) break; p = q; if ((q = scanByte(p, m)) <= p) break; p = q; if ((q = scan(p, m, '.')) <= p) break; p = q; if ((q = scanByte(p, m)) <= p) break; p = q; if ((q = scan(p, m, '.')) <= p) break; p = q; if ((q = scanByte(p, m)) <= p) break; p = q; if (q < m) break; return q; } fail("Malformed IPv4 address", q); return -1; } // Take an IPv4 address: Throw an exception if the given interval // contains anything except an IPv4 address // private int takeIPv4Address(int start, int n, String expected) throws URISyntaxException { int p = scanIPv4Address(start, n, true); if (p <= start) failExpecting(expected, start); return p; } // Attempt to parse an IPv4 address, returning -1 on failure but // allowing the given interval to contain [:] after // the IPv4 address. // private int parseIPv4Address(int start, int n) { int p; try { p = scanIPv4Address(start, n, false); } catch (URISyntaxException x) { return -1; } catch (NumberFormatException nfe) { return -1; } if (p > start && p < n) { // IPv4 address is followed by something - check that // it's a ":" as this is the only valid character to // follow an address. if (charAt(p) != ':') { p = -1; } } if (p > start) host = substring(start, p); return p; } // hostname = domainlabel [ "." ] | 1*( domainlabel "." ) toplabel [ "." ] // domainlabel = alphanum | alphanum *( alphanum | "-" ) alphanum // toplabel = alpha | alpha *( alphanum | "-" ) alphanum // private int parseHostname(int start, int n) throws URISyntaxException { int p = start; int q; int l = -1; // Start of last parsed label do { // domainlabel = alphanum [ *( alphanum | "-" ) alphanum ] q = scan(p, n, L_ALPHANUM, H_ALPHANUM); if (q <= p) break; l = p; if (q > p) { p = q; q = scan(p, n, L_ALPHANUM | L_DASH, H_ALPHANUM | H_DASH); if (q > p) { if (charAt(q - 1) == '-') fail("Illegal character in hostname", q - 1); p = q; } } q = scan(p, n, '.'); if (q <= p) break; p = q; } while (p < n); if ((p < n) && !at(p, n, ':')) fail("Illegal character in hostname", p); if (l < 0) failExpecting("hostname", start); // for a fully qualified hostname check that the rightmost // label starts with an alpha character. if (l > start && !match(charAt(l), L_ALPHA, H_ALPHA)) { fail("Illegal character in hostname", l); } host = substring(start, p); return p; } // IPv6 address parsing, from RFC2373: IPv6 Addressing Architecture // // Bug: The grammar in RFC2373 Appendix B does not allow addresses of // the form ::12.34.56.78, which are clearly shown in the examples // earlier in the document. Here is the original grammar: // // IPv6address = hexpart [ ":" IPv4address ] // hexpart = hexseq | hexseq "::" [ hexseq ] | "::" [ hexseq ] // hexseq = hex4 *( ":" hex4) // hex4 = 1*4HEXDIG // // We therefore use the following revised grammar: // // IPv6address = hexseq [ ":" IPv4address ] // | hexseq [ "::" [ hexpost ] ] // | "::" [ hexpost ] // hexpost = hexseq | hexseq ":" IPv4address | IPv4address // hexseq = hex4 *( ":" hex4) // hex4 = 1*4HEXDIG // // This covers all and only the following cases: // // hexseq // hexseq : IPv4address // hexseq :: // hexseq :: hexseq // hexseq :: hexseq : IPv4address // hexseq :: IPv4address // :: hexseq // :: hexseq : IPv4address // :: IPv4address // :: // // Additionally we constrain the IPv6 address as follows :- // // i. IPv6 addresses without compressed zeros should contain // exactly 16 bytes. // // ii. IPv6 addresses with compressed zeros should contain // less than 16 bytes. private int ipv6byteCount = 0; private int parseIPv6Reference(int start, int n) throws URISyntaxException { int p = start; int q; boolean compressedZeros = false; q = scanHexSeq(p, n); if (q > p) { p = q; if (at(p, n, "::")) { compressedZeros = true; p = scanHexPost(p + 2, n); } else if (at(p, n, ':')) { p = takeIPv4Address(p + 1, n, "IPv4 address"); ipv6byteCount += 4; } } else if (at(p, n, "::")) { compressedZeros = true; p = scanHexPost(p + 2, n); } if (p < n) fail("Malformed IPv6 address", start); if (ipv6byteCount > 16) fail("IPv6 address too long", start); if (!compressedZeros && ipv6byteCount < 16) fail("IPv6 address too short", start); if (compressedZeros && ipv6byteCount == 16) fail("Malformed IPv6 address", start); return p; } private int scanHexPost(int start, int n) throws URISyntaxException { int p = start; int q; if (p == n) return p; q = scanHexSeq(p, n); if (q > p) { p = q; if (at(p, n, ':')) { p++; p = takeIPv4Address(p, n, "hex digits or IPv4 address"); ipv6byteCount += 4; } } else { p = takeIPv4Address(p, n, "hex digits or IPv4 address"); ipv6byteCount += 4; } return p; } // Scan a hex sequence; return -1 if one could not be scanned // private int scanHexSeq(int start, int n) throws URISyntaxException { int p = start; int q; q = scan(p, n, L_HEX, H_HEX); if (q <= p) return -1; if (at(q, n, '.')) // Beginning of IPv4 address return -1; if (q > p + 4) fail("IPv6 hexadecimal digit sequence too long", p); ipv6byteCount += 2; p = q; while (p < n) { if (!at(p, n, ':')) break; if (at(p + 1, n, ':')) break; // "::" p++; q = scan(p, n, L_HEX, H_HEX); if (q <= p) failExpecting("digits for an IPv6 address", p); if (at(q, n, '.')) { // Beginning of IPv4 address p--; break; } if (q > p + 4) fail("IPv6 hexadecimal digit sequence too long", p); ipv6byteCount += 2; p = q; } return p; } } }

X Tutup