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ObjectOutputStream.java
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2474 lines (2288 loc) · 89.7 KB
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/*
* Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*
*
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*
*/
package java.io;
import java.io.ObjectStreamClass.WeakClassKey;
import java.lang.ref.ReferenceQueue;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import static java.io.ObjectStreamClass.processQueue;
import java.io.SerialCallbackContext;
import sun.reflect.misc.ReflectUtil;
/**
* An ObjectOutputStream writes primitive data types and graphs of Java objects
* to an OutputStream. The objects can be read (reconstituted) using an
* ObjectInputStream. Persistent storage of objects can be accomplished by
* using a file for the stream. If the stream is a network socket stream, the
* objects can be reconstituted on another host or in another process.
*
* <p>Only objects that support the java.io.Serializable interface can be
* written to streams. The class of each serializable object is encoded
* including the class name and signature of the class, the values of the
* object's fields and arrays, and the closure of any other objects referenced
* from the initial objects.
*
* <p>The method writeObject is used to write an object to the stream. Any
* object, including Strings and arrays, is written with writeObject. Multiple
* objects or primitives can be written to the stream. The objects must be
* read back from the corresponding ObjectInputstream with the same types and
* in the same order as they were written.
*
* <p>Primitive data types can also be written to the stream using the
* appropriate methods from DataOutput. Strings can also be written using the
* writeUTF method.
*
* <p>The default serialization mechanism for an object writes the class of the
* object, the class signature, and the values of all non-transient and
* non-static fields. References to other objects (except in transient or
* static fields) cause those objects to be written also. Multiple references
* to a single object are encoded using a reference sharing mechanism so that
* graphs of objects can be restored to the same shape as when the original was
* written.
*
* <p>For example to write an object that can be read by the example in
* ObjectInputStream:
* <br>
* <pre>
* FileOutputStream fos = new FileOutputStream("t.tmp");
* ObjectOutputStream oos = new ObjectOutputStream(fos);
*
* oos.writeInt(12345);
* oos.writeObject("Today");
* oos.writeObject(new Date());
*
* oos.close();
* </pre>
*
* <p>Classes that require special handling during the serialization and
* deserialization process must implement special methods with these exact
* signatures:
* <br>
* <pre>
* private void readObject(java.io.ObjectInputStream stream)
* throws IOException, ClassNotFoundException;
* private void writeObject(java.io.ObjectOutputStream stream)
* throws IOException
* private void readObjectNoData()
* throws ObjectStreamException;
* </pre>
*
* <p>The writeObject method is responsible for writing the state of the object
* for its particular class so that the corresponding readObject method can
* restore it. The method does not need to concern itself with the state
* belonging to the object's superclasses or subclasses. State is saved by
* writing the individual fields to the ObjectOutputStream using the
* writeObject method or by using the methods for primitive data types
* supported by DataOutput.
*
* <p>Serialization does not write out the fields of any object that does not
* implement the java.io.Serializable interface. Subclasses of Objects that
* are not serializable can be serializable. In this case the non-serializable
* class must have a no-arg constructor to allow its fields to be initialized.
* In this case it is the responsibility of the subclass to save and restore
* the state of the non-serializable class. It is frequently the case that the
* fields of that class are accessible (public, package, or protected) or that
* there are get and set methods that can be used to restore the state.
*
* <p>Serialization of an object can be prevented by implementing writeObject
* and readObject methods that throw the NotSerializableException. The
* exception will be caught by the ObjectOutputStream and abort the
* serialization process.
*
* <p>Implementing the Externalizable interface allows the object to assume
* complete control over the contents and format of the object's serialized
* form. The methods of the Externalizable interface, writeExternal and
* readExternal, are called to save and restore the objects state. When
* implemented by a class they can write and read their own state using all of
* the methods of ObjectOutput and ObjectInput. It is the responsibility of
* the objects to handle any versioning that occurs.
*
* <p>Enum constants are serialized differently than ordinary serializable or
* externalizable objects. The serialized form of an enum constant consists
* solely of its name; field values of the constant are not transmitted. To
* serialize an enum constant, ObjectOutputStream writes the string returned by
* the constant's name method. Like other serializable or externalizable
* objects, enum constants can function as the targets of back references
* appearing subsequently in the serialization stream. The process by which
* enum constants are serialized cannot be customized; any class-specific
* writeObject and writeReplace methods defined by enum types are ignored
* during serialization. Similarly, any serialPersistentFields or
* serialVersionUID field declarations are also ignored--all enum types have a
* fixed serialVersionUID of 0L.
*
* <p>Primitive data, excluding serializable fields and externalizable data, is
* written to the ObjectOutputStream in block-data records. A block data record
* is composed of a header and data. The block data header consists of a marker
* and the number of bytes to follow the header. Consecutive primitive data
* writes are merged into one block-data record. The blocking factor used for
* a block-data record will be 1024 bytes. Each block-data record will be
* filled up to 1024 bytes, or be written whenever there is a termination of
* block-data mode. Calls to the ObjectOutputStream methods writeObject,
* defaultWriteObject and writeFields initially terminate any existing
* block-data record.
*
* @author Mike Warres
* @author Roger Riggs
* @see java.io.DataOutput
* @see java.io.ObjectInputStream
* @see java.io.Serializable
* @see java.io.Externalizable
* @see <a href="../../../platform/serialization/spec/output.html">Object Serialization Specification, Section 2, Object Output Classes</a>
* @since JDK1.1
*/
public class ObjectOutputStream
extends OutputStream implements ObjectOutput, ObjectStreamConstants
{
private static class Caches {
/** cache of subclass security audit results */
static final ConcurrentMap<WeakClassKey,Boolean> subclassAudits =
new ConcurrentHashMap<>();
/** queue for WeakReferences to audited subclasses */
static final ReferenceQueue<Class<?>> subclassAuditsQueue =
new ReferenceQueue<>();
}
/** filter stream for handling block data conversion */
private final BlockDataOutputStream bout;
/** obj -> wire handle map */
private final HandleTable handles;
/** obj -> replacement obj map */
private final ReplaceTable subs;
/** stream protocol version */
private int protocol = PROTOCOL_VERSION_2;
/** recursion depth */
private int depth;
/** buffer for writing primitive field values */
private byte[] primVals;
/** if true, invoke writeObjectOverride() instead of writeObject() */
private final boolean enableOverride;
/** if true, invoke replaceObject() */
private boolean enableReplace;
// values below valid only during upcalls to writeObject()/writeExternal()
/**
* Context during upcalls to class-defined writeObject methods; holds
* object currently being serialized and descriptor for current class.
* Null when not during writeObject upcall.
*/
private SerialCallbackContext curContext;
/** current PutField object */
private PutFieldImpl curPut;
/** custom storage for debug trace info */
private final DebugTraceInfoStack debugInfoStack;
/**
* value of "sun.io.serialization.extendedDebugInfo" property,
* as true or false for extended information about exception's place
*/
private static final boolean extendedDebugInfo =
java.security.AccessController.doPrivileged(
new sun.security.action.GetBooleanAction(
"sun.io.serialization.extendedDebugInfo")).booleanValue();
/**
* Creates an ObjectOutputStream that writes to the specified OutputStream.
* This constructor writes the serialization stream header to the
* underlying stream; callers may wish to flush the stream immediately to
* ensure that constructors for receiving ObjectInputStreams will not block
* when reading the header.
*
* <p>If a security manager is installed, this constructor will check for
* the "enableSubclassImplementation" SerializablePermission when invoked
* directly or indirectly by the constructor of a subclass which overrides
* the ObjectOutputStream.putFields or ObjectOutputStream.writeUnshared
* methods.
*
* @param out output stream to write to
* @throws IOException if an I/O error occurs while writing stream header
* @throws SecurityException if untrusted subclass illegally overrides
* security-sensitive methods
* @throws NullPointerException if <code>out</code> is <code>null</code>
* @since 1.4
* @see ObjectOutputStream#ObjectOutputStream()
* @see ObjectOutputStream#putFields()
* @see ObjectInputStream#ObjectInputStream(InputStream)
*/
public ObjectOutputStream(OutputStream out) throws IOException {
verifySubclass();
bout = new BlockDataOutputStream(out);
handles = new HandleTable(10, (float) 3.00);
subs = new ReplaceTable(10, (float) 3.00);
enableOverride = false;
writeStreamHeader();
bout.setBlockDataMode(true);
if (extendedDebugInfo) {
debugInfoStack = new DebugTraceInfoStack();
} else {
debugInfoStack = null;
}
}
/**
* Provide a way for subclasses that are completely reimplementing
* ObjectOutputStream to not have to allocate private data just used by
* this implementation of ObjectOutputStream.
*
* <p>If there is a security manager installed, this method first calls the
* security manager's <code>checkPermission</code> method with a
* <code>SerializablePermission("enableSubclassImplementation")</code>
* permission to ensure it's ok to enable subclassing.
*
* @throws SecurityException if a security manager exists and its
* <code>checkPermission</code> method denies enabling
* subclassing.
* @throws IOException if an I/O error occurs while creating this stream
* @see SecurityManager#checkPermission
* @see java.io.SerializablePermission
*/
protected ObjectOutputStream() throws IOException, SecurityException {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
}
bout = null;
handles = null;
subs = null;
enableOverride = true;
debugInfoStack = null;
}
/**
* Specify stream protocol version to use when writing the stream.
*
* <p>This routine provides a hook to enable the current version of
* Serialization to write in a format that is backwards compatible to a
* previous version of the stream format.
*
* <p>Every effort will be made to avoid introducing additional
* backwards incompatibilities; however, sometimes there is no
* other alternative.
*
* @param version use ProtocolVersion from java.io.ObjectStreamConstants.
* @throws IllegalStateException if called after any objects
* have been serialized.
* @throws IllegalArgumentException if invalid version is passed in.
* @throws IOException if I/O errors occur
* @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
* @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_2
* @since 1.2
*/
public void useProtocolVersion(int version) throws IOException {
if (handles.size() != 0) {
// REMIND: implement better check for pristine stream?
throw new IllegalStateException("stream non-empty");
}
switch (version) {
case PROTOCOL_VERSION_1:
case PROTOCOL_VERSION_2:
protocol = version;
break;
default:
throw new IllegalArgumentException(
"unknown version: " + version);
}
}
/**
* Write the specified object to the ObjectOutputStream. The class of the
* object, the signature of the class, and the values of the non-transient
* and non-static fields of the class and all of its supertypes are
* written. Default serialization for a class can be overridden using the
* writeObject and the readObject methods. Objects referenced by this
* object are written transitively so that a complete equivalent graph of
* objects can be reconstructed by an ObjectInputStream.
*
* <p>Exceptions are thrown for problems with the OutputStream and for
* classes that should not be serialized. All exceptions are fatal to the
* OutputStream, which is left in an indeterminate state, and it is up to
* the caller to ignore or recover the stream state.
*
* @throws InvalidClassException Something is wrong with a class used by
* serialization.
* @throws NotSerializableException Some object to be serialized does not
* implement the java.io.Serializable interface.
* @throws IOException Any exception thrown by the underlying
* OutputStream.
*/
public final void writeObject(Object obj) throws IOException {
if (enableOverride) {
writeObjectOverride(obj);
return;
}
try {
writeObject0(obj, false);
} catch (IOException ex) {
if (depth == 0) {
writeFatalException(ex);
}
throw ex;
}
}
/**
* Method used by subclasses to override the default writeObject method.
* This method is called by trusted subclasses of ObjectInputStream that
* constructed ObjectInputStream using the protected no-arg constructor.
* The subclass is expected to provide an override method with the modifier
* "final".
*
* @param obj object to be written to the underlying stream
* @throws IOException if there are I/O errors while writing to the
* underlying stream
* @see #ObjectOutputStream()
* @see #writeObject(Object)
* @since 1.2
*/
protected void writeObjectOverride(Object obj) throws IOException {
}
/**
* Writes an "unshared" object to the ObjectOutputStream. This method is
* identical to writeObject, except that it always writes the given object
* as a new, unique object in the stream (as opposed to a back-reference
* pointing to a previously serialized instance). Specifically:
* <ul>
* <li>An object written via writeUnshared is always serialized in the
* same manner as a newly appearing object (an object that has not
* been written to the stream yet), regardless of whether or not the
* object has been written previously.
*
* <li>If writeObject is used to write an object that has been previously
* written with writeUnshared, the previous writeUnshared operation
* is treated as if it were a write of a separate object. In other
* words, ObjectOutputStream will never generate back-references to
* object data written by calls to writeUnshared.
* </ul>
* While writing an object via writeUnshared does not in itself guarantee a
* unique reference to the object when it is deserialized, it allows a
* single object to be defined multiple times in a stream, so that multiple
* calls to readUnshared by the receiver will not conflict. Note that the
* rules described above only apply to the base-level object written with
* writeUnshared, and not to any transitively referenced sub-objects in the
* object graph to be serialized.
*
* <p>ObjectOutputStream subclasses which override this method can only be
* constructed in security contexts possessing the
* "enableSubclassImplementation" SerializablePermission; any attempt to
* instantiate such a subclass without this permission will cause a
* SecurityException to be thrown.
*
* @param obj object to write to stream
* @throws NotSerializableException if an object in the graph to be
* serialized does not implement the Serializable interface
* @throws InvalidClassException if a problem exists with the class of an
* object to be serialized
* @throws IOException if an I/O error occurs during serialization
* @since 1.4
*/
public void writeUnshared(Object obj) throws IOException {
try {
writeObject0(obj, true);
} catch (IOException ex) {
if (depth == 0) {
writeFatalException(ex);
}
throw ex;
}
}
/**
* Write the non-static and non-transient fields of the current class to
* this stream. This may only be called from the writeObject method of the
* class being serialized. It will throw the NotActiveException if it is
* called otherwise.
*
* @throws IOException if I/O errors occur while writing to the underlying
* <code>OutputStream</code>
*/
public void defaultWriteObject() throws IOException {
SerialCallbackContext ctx = curContext;
if (ctx == null) {
throw new NotActiveException("not in call to writeObject");
}
Object curObj = ctx.getObj();
ObjectStreamClass curDesc = ctx.getDesc();
bout.setBlockDataMode(false);
defaultWriteFields(curObj, curDesc);
bout.setBlockDataMode(true);
}
/**
* Retrieve the object used to buffer persistent fields to be written to
* the stream. The fields will be written to the stream when writeFields
* method is called.
*
* @return an instance of the class Putfield that holds the serializable
* fields
* @throws IOException if I/O errors occur
* @since 1.2
*/
public ObjectOutputStream.PutField putFields() throws IOException {
if (curPut == null) {
SerialCallbackContext ctx = curContext;
if (ctx == null) {
throw new NotActiveException("not in call to writeObject");
}
Object curObj = ctx.getObj();
ObjectStreamClass curDesc = ctx.getDesc();
curPut = new PutFieldImpl(curDesc);
}
return curPut;
}
/**
* Write the buffered fields to the stream.
*
* @throws IOException if I/O errors occur while writing to the underlying
* stream
* @throws NotActiveException Called when a classes writeObject method was
* not called to write the state of the object.
* @since 1.2
*/
public void writeFields() throws IOException {
if (curPut == null) {
throw new NotActiveException("no current PutField object");
}
bout.setBlockDataMode(false);
curPut.writeFields();
bout.setBlockDataMode(true);
}
/**
* Reset will disregard the state of any objects already written to the
* stream. The state is reset to be the same as a new ObjectOutputStream.
* The current point in the stream is marked as reset so the corresponding
* ObjectInputStream will be reset at the same point. Objects previously
* written to the stream will not be referred to as already being in the
* stream. They will be written to the stream again.
*
* @throws IOException if reset() is invoked while serializing an object.
*/
public void reset() throws IOException {
if (depth != 0) {
throw new IOException("stream active");
}
bout.setBlockDataMode(false);
bout.writeByte(TC_RESET);
clear();
bout.setBlockDataMode(true);
}
/**
* Subclasses may implement this method to allow class data to be stored in
* the stream. By default this method does nothing. The corresponding
* method in ObjectInputStream is resolveClass. This method is called
* exactly once for each unique class in the stream. The class name and
* signature will have already been written to the stream. This method may
* make free use of the ObjectOutputStream to save any representation of
* the class it deems suitable (for example, the bytes of the class file).
* The resolveClass method in the corresponding subclass of
* ObjectInputStream must read and use any data or objects written by
* annotateClass.
*
* @param cl the class to annotate custom data for
* @throws IOException Any exception thrown by the underlying
* OutputStream.
*/
protected void annotateClass(Class<?> cl) throws IOException {
}
/**
* Subclasses may implement this method to store custom data in the stream
* along with descriptors for dynamic proxy classes.
*
* <p>This method is called exactly once for each unique proxy class
* descriptor in the stream. The default implementation of this method in
* <code>ObjectOutputStream</code> does nothing.
*
* <p>The corresponding method in <code>ObjectInputStream</code> is
* <code>resolveProxyClass</code>. For a given subclass of
* <code>ObjectOutputStream</code> that overrides this method, the
* <code>resolveProxyClass</code> method in the corresponding subclass of
* <code>ObjectInputStream</code> must read any data or objects written by
* <code>annotateProxyClass</code>.
*
* @param cl the proxy class to annotate custom data for
* @throws IOException any exception thrown by the underlying
* <code>OutputStream</code>
* @see ObjectInputStream#resolveProxyClass(String[])
* @since 1.3
*/
protected void annotateProxyClass(Class<?> cl) throws IOException {
}
/**
* This method will allow trusted subclasses of ObjectOutputStream to
* substitute one object for another during serialization. Replacing
* objects is disabled until enableReplaceObject is called. The
* enableReplaceObject method checks that the stream requesting to do
* replacement can be trusted. The first occurrence of each object written
* into the serialization stream is passed to replaceObject. Subsequent
* references to the object are replaced by the object returned by the
* original call to replaceObject. To ensure that the private state of
* objects is not unintentionally exposed, only trusted streams may use
* replaceObject.
*
* <p>The ObjectOutputStream.writeObject method takes a parameter of type
* Object (as opposed to type Serializable) to allow for cases where
* non-serializable objects are replaced by serializable ones.
*
* <p>When a subclass is replacing objects it must insure that either a
* complementary substitution must be made during deserialization or that
* the substituted object is compatible with every field where the
* reference will be stored. Objects whose type is not a subclass of the
* type of the field or array element abort the serialization by raising an
* exception and the object is not be stored.
*
* <p>This method is called only once when each object is first
* encountered. All subsequent references to the object will be redirected
* to the new object. This method should return the object to be
* substituted or the original object.
*
* <p>Null can be returned as the object to be substituted, but may cause
* NullReferenceException in classes that contain references to the
* original object since they may be expecting an object instead of
* null.
*
* @param obj the object to be replaced
* @return the alternate object that replaced the specified one
* @throws IOException Any exception thrown by the underlying
* OutputStream.
*/
protected Object replaceObject(Object obj) throws IOException {
return obj;
}
/**
* Enable the stream to do replacement of objects in the stream. When
* enabled, the replaceObject method is called for every object being
* serialized.
*
* <p>If <code>enable</code> is true, and there is a security manager
* installed, this method first calls the security manager's
* <code>checkPermission</code> method with a
* <code>SerializablePermission("enableSubstitution")</code> permission to
* ensure it's ok to enable the stream to do replacement of objects in the
* stream.
*
* @param enable boolean parameter to enable replacement of objects
* @return the previous setting before this method was invoked
* @throws SecurityException if a security manager exists and its
* <code>checkPermission</code> method denies enabling the stream
* to do replacement of objects in the stream.
* @see SecurityManager#checkPermission
* @see java.io.SerializablePermission
*/
protected boolean enableReplaceObject(boolean enable)
throws SecurityException
{
if (enable == enableReplace) {
return enable;
}
if (enable) {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkPermission(SUBSTITUTION_PERMISSION);
}
}
enableReplace = enable;
return !enableReplace;
}
/**
* The writeStreamHeader method is provided so subclasses can append or
* prepend their own header to the stream. It writes the magic number and
* version to the stream.
*
* @throws IOException if I/O errors occur while writing to the underlying
* stream
*/
protected void writeStreamHeader() throws IOException {
bout.writeShort(STREAM_MAGIC);
bout.writeShort(STREAM_VERSION);
}
/**
* Write the specified class descriptor to the ObjectOutputStream. Class
* descriptors are used to identify the classes of objects written to the
* stream. Subclasses of ObjectOutputStream may override this method to
* customize the way in which class descriptors are written to the
* serialization stream. The corresponding method in ObjectInputStream,
* <code>readClassDescriptor</code>, should then be overridden to
* reconstitute the class descriptor from its custom stream representation.
* By default, this method writes class descriptors according to the format
* defined in the Object Serialization specification.
*
* <p>Note that this method will only be called if the ObjectOutputStream
* is not using the old serialization stream format (set by calling
* ObjectOutputStream's <code>useProtocolVersion</code> method). If this
* serialization stream is using the old format
* (<code>PROTOCOL_VERSION_1</code>), the class descriptor will be written
* internally in a manner that cannot be overridden or customized.
*
* @param desc class descriptor to write to the stream
* @throws IOException If an I/O error has occurred.
* @see java.io.ObjectInputStream#readClassDescriptor()
* @see #useProtocolVersion(int)
* @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
* @since 1.3
*/
protected void writeClassDescriptor(ObjectStreamClass desc)
throws IOException
{
desc.writeNonProxy(this);
}
/**
* Writes a byte. This method will block until the byte is actually
* written.
*
* @param val the byte to be written to the stream
* @throws IOException If an I/O error has occurred.
*/
public void write(int val) throws IOException {
bout.write(val);
}
/**
* Writes an array of bytes. This method will block until the bytes are
* actually written.
*
* @param buf the data to be written
* @throws IOException If an I/O error has occurred.
*/
public void write(byte[] buf) throws IOException {
bout.write(buf, 0, buf.length, false);
}
/**
* Writes a sub array of bytes.
*
* @param buf the data to be written
* @param off the start offset in the data
* @param len the number of bytes that are written
* @throws IOException If an I/O error has occurred.
*/
public void write(byte[] buf, int off, int len) throws IOException {
if (buf == null) {
throw new NullPointerException();
}
int endoff = off + len;
if (off < 0 || len < 0 || endoff > buf.length || endoff < 0) {
throw new IndexOutOfBoundsException();
}
bout.write(buf, off, len, false);
}
/**
* Flushes the stream. This will write any buffered output bytes and flush
* through to the underlying stream.
*
* @throws IOException If an I/O error has occurred.
*/
public void flush() throws IOException {
bout.flush();
}
/**
* Drain any buffered data in ObjectOutputStream. Similar to flush but
* does not propagate the flush to the underlying stream.
*
* @throws IOException if I/O errors occur while writing to the underlying
* stream
*/
protected void drain() throws IOException {
bout.drain();
}
/**
* Closes the stream. This method must be called to release any resources
* associated with the stream.
*
* @throws IOException If an I/O error has occurred.
*/
public void close() throws IOException {
flush();
clear();
bout.close();
}
/**
* Writes a boolean.
*
* @param val the boolean to be written
* @throws IOException if I/O errors occur while writing to the underlying
* stream
*/
public void writeBoolean(boolean val) throws IOException {
bout.writeBoolean(val);
}
/**
* Writes an 8 bit byte.
*
* @param val the byte value to be written
* @throws IOException if I/O errors occur while writing to the underlying
* stream
*/
public void writeByte(int val) throws IOException {
bout.writeByte(val);
}
/**
* Writes a 16 bit short.
*
* @param val the short value to be written
* @throws IOException if I/O errors occur while writing to the underlying
* stream
*/
public void writeShort(int val) throws IOException {
bout.writeShort(val);
}
/**
* Writes a 16 bit char.
*
* @param val the char value to be written
* @throws IOException if I/O errors occur while writing to the underlying
* stream
*/
public void writeChar(int val) throws IOException {
bout.writeChar(val);
}
/**
* Writes a 32 bit int.
*
* @param val the integer value to be written
* @throws IOException if I/O errors occur while writing to the underlying
* stream
*/
public void writeInt(int val) throws IOException {
bout.writeInt(val);
}
/**
* Writes a 64 bit long.
*
* @param val the long value to be written
* @throws IOException if I/O errors occur while writing to the underlying
* stream
*/
public void writeLong(long val) throws IOException {
bout.writeLong(val);
}
/**
* Writes a 32 bit float.
*
* @param val the float value to be written
* @throws IOException if I/O errors occur while writing to the underlying
* stream
*/
public void writeFloat(float val) throws IOException {
bout.writeFloat(val);
}
/**
* Writes a 64 bit double.
*
* @param val the double value to be written
* @throws IOException if I/O errors occur while writing to the underlying
* stream
*/
public void writeDouble(double val) throws IOException {
bout.writeDouble(val);
}
/**
* Writes a String as a sequence of bytes.
*
* @param str the String of bytes to be written
* @throws IOException if I/O errors occur while writing to the underlying
* stream
*/
public void writeBytes(String str) throws IOException {
bout.writeBytes(str);
}
/**
* Writes a String as a sequence of chars.
*
* @param str the String of chars to be written
* @throws IOException if I/O errors occur while writing to the underlying
* stream
*/
public void writeChars(String str) throws IOException {
bout.writeChars(str);
}
/**
* Primitive data write of this String in
* <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
* format. Note that there is a
* significant difference between writing a String into the stream as
* primitive data or as an Object. A String instance written by writeObject
* is written into the stream as a String initially. Future writeObject()
* calls write references to the string into the stream.
*
* @param str the String to be written
* @throws IOException if I/O errors occur while writing to the underlying
* stream
*/
public void writeUTF(String str) throws IOException {
bout.writeUTF(str);
}
/**
* Provide programmatic access to the persistent fields to be written
* to ObjectOutput.
*
* @since 1.2
*/
public static abstract class PutField {
/**
* Put the value of the named boolean field into the persistent field.
*
* @param name the name of the serializable field
* @param val the value to assign to the field
* @throws IllegalArgumentException if <code>name</code> does not
* match the name of a serializable field for the class whose fields
* are being written, or if the type of the named field is not
* <code>boolean</code>
*/
public abstract void put(String name, boolean val);
/**
* Put the value of the named byte field into the persistent field.
*
* @param name the name of the serializable field
* @param val the value to assign to the field
* @throws IllegalArgumentException if <code>name</code> does not
* match the name of a serializable field for the class whose fields
* are being written, or if the type of the named field is not
* <code>byte</code>
*/
public abstract void put(String name, byte val);
/**
* Put the value of the named char field into the persistent field.
*
* @param name the name of the serializable field
* @param val the value to assign to the field
* @throws IllegalArgumentException if <code>name</code> does not
* match the name of a serializable field for the class whose fields
* are being written, or if the type of the named field is not
* <code>char</code>
*/
public abstract void put(String name, char val);
/**
* Put the value of the named short field into the persistent field.
*
* @param name the name of the serializable field
* @param val the value to assign to the field
* @throws IllegalArgumentException if <code>name</code> does not
* match the name of a serializable field for the class whose fields
* are being written, or if the type of the named field is not
* <code>short</code>
*/
public abstract void put(String name, short val);
/**
* Put the value of the named int field into the persistent field.
*
* @param name the name of the serializable field
* @param val the value to assign to the field
* @throws IllegalArgumentException if <code>name</code> does not
* match the name of a serializable field for the class whose fields
* are being written, or if the type of the named field is not
* <code>int</code>
*/
public abstract void put(String name, int val);
/**
* Put the value of the named long field into the persistent field.
*
* @param name the name of the serializable field
* @param val the value to assign to the field
* @throws IllegalArgumentException if <code>name</code> does not
* match the name of a serializable field for the class whose fields
* are being written, or if the type of the named field is not
* <code>long</code>
*/
public abstract void put(String name, long val);
/**
* Put the value of the named float field into the persistent field.
*
* @param name the name of the serializable field
* @param val the value to assign to the field
* @throws IllegalArgumentException if <code>name</code> does not
* match the name of a serializable field for the class whose fields
* are being written, or if the type of the named field is not
* <code>float</code>
*/
public abstract void put(String name, float val);
/**
* Put the value of the named double field into the persistent field.
*
* @param name the name of the serializable field
* @param val the value to assign to the field
* @throws IllegalArgumentException if <code>name</code> does not
* match the name of a serializable field for the class whose fields
* are being written, or if the type of the named field is not
* <code>double</code>
*/
public abstract void put(String name, double val);
/**
* Put the value of the named Object field into the persistent field.
*
* @param name the name of the serializable field
* @param val the value to assign to the field
* (which may be <code>null</code>)
* @throws IllegalArgumentException if <code>name</code> does not
* match the name of a serializable field for the class whose fields
* are being written, or if the type of the named field is not a
* reference type
*/
public abstract void put(String name, Object val);
/**
* Write the data and fields to the specified ObjectOutput stream,
* which must be the same stream that produced this
* <code>PutField</code> object.
*
* @param out the stream to write the data and fields to
* @throws IOException if I/O errors occur while writing to the
* underlying stream
* @throws IllegalArgumentException if the specified stream is not
* the same stream that produced this <code>PutField</code>
* object
* @deprecated This method does not write the values contained by this