get and opt methods for accessing
* the values by name, and put methods for adding or replacing
* values by name. The values can be any of these types: Boolean,
* JSONArray, JSONObject, Number,
* String, or the JSONObject.NULL object. A
* JSONObject constructor can be used to convert an external form JSON text
* into an internal form whose values can be retrieved with the
* get and opt methods, or to convert values into a
* JSON text using the put and toString methods. A
* get method returns a value if one can be found, and throws an
* exception if one cannot be found. An opt method returns a
* default value instead of throwing an exception, and so is useful for
* obtaining optional values.
*
* The generic get() and opt() methods return an
* object, which you can cast or query for type. There are also typed
* get and opt methods that do type checking and type
* coercion for you. The opt methods differ from the get methods in that they
* do not throw. Instead, they return a specified value, such as null.
*
* The put methods add or replace values in an object. For
* example,
*
*
* myString = new JSONObject()
* .put("JSON", "Hello, World!").toString();
*
*
* produces the string {"JSON": "Hello, World"}.
*
* The texts produced by the toString methods strictly conform to
* the JSON syntax rules. The constructors are more forgiving in the texts they
* will accept:
*
, (comma) may appear just
* before the closing brace.' (single
* quote).{ } [ ] / \ : , # and if they do not look like numbers and
* if they are not the reserved words true, false,
* or null.NULL object than to use Java's null value.
* JSONObject.NULL.equals(null) returns true.
* JSONObject.NULL.toString() returns "null".
*/
public static final Object NULL = new Null();
/**
* Construct an empty JSONObject.
*/
public JSONObject() {
this.map = new HashMap"get" or
* "is" followed by an uppercase letter, the method is invoked,
* and a key and the value returned from the getter method are put into the
* new JSONObject.
*
* The key is formed by removing the "get" or "is"
* prefix. If the second remaining character is not upper case, then the
* first character is converted to lower case.
*
* For example, if an object has a method named "getName", and
* if the result of calling object.getName() is
* "Larry Fine", then the JSONObject will contain
* "name": "Larry Fine".
*
* @param bean
* An object that has getter methods that should be used to make
* a JSONObject.
*/
public JSONObject(Object bean) {
this();
this.populateMap(bean);
}
/**
* Construct a JSONObject from an Object, using reflection to find the
* public members. The resulting JSONObject's keys will be the strings from
* the names array, and the values will be the field values associated with
* those keys in the object. If a key is not found or not visible, then it
* will not be copied into the new JSONObject.
*
* @param object
* An object that has fields that should be used to make a
* JSONObject.
* @param names
* An array of strings, the names of the fields to be obtained
* from the object.
*/
public JSONObject(Object object, String names[]) {
this();
Class c = object.getClass();
for (int i = 0; i < names.length; i += 1) {
String name = names[i];
try {
this.putOpt(name, c.getField(name).get(object));
} catch (Exception ignore) {
}
}
}
/**
* Construct a JSONObject from a source JSON text string. This is the most
* commonly used JSONObject constructor.
*
* @param source
* A string beginning with { (left
* brace) and ending with }
* (right brace).
* @exception JSONException
* If there is a syntax error in the source string or a
* duplicated key.
*/
public JSONObject(String source) throws JSONException {
this(new JSONTokener(source));
}
/**
* Construct a JSONObject from a ResourceBundle.
*
* @param baseName
* The ResourceBundle base name.
* @param locale
* The Locale to load the ResourceBundle for.
* @throws JSONException
* If any JSONExceptions are detected.
*/
public JSONObject(String baseName, Locale locale) throws JSONException {
this();
ResourceBundle bundle = ResourceBundle.getBundle(baseName, locale,
Thread.currentThread().getContextClassLoader());
// Iterate through the keys in the bundle.
Enumeration
* Warning: This method assumes that the data structure is acyclical.
*
* @return a printable, displayable, portable, transmittable representation
* of the object, beginning with { (left
* brace) and ending with } (right
* brace).
*/
public String toString() {
try {
return this.toString(0);
} catch (Exception e) {
return null;
}
}
/**
* Make a prettyprinted JSON text of this JSONObject.
*
* Warning: This method assumes that the data structure is acyclical.
*
* @param indentFactor
* The number of spaces to add to each level of indentation.
* @return a printable, displayable, portable, transmittable representation
* of the object, beginning with { (left
* brace) and ending with } (right
* brace).
* @throws JSONException
* If the object contains an invalid number.
*/
public String toString(int indentFactor) throws JSONException {
StringWriter w = new StringWriter();
synchronized (w.getBuffer()) {
return this.write(w, indentFactor, 0).toString();
}
}
/**
* Make a JSON text of an Object value. If the object has an
* value.toJSONString() method, then that method will be used to produce the
* JSON text. The method is required to produce a strictly conforming text.
* If the object does not contain a toJSONString method (which is the most
* common case), then a text will be produced by other means. If the value
* is an array or Collection, then a JSONArray will be made from it and its
* toJSONString method will be called. If the value is a MAP, then a
* JSONObject will be made from it and its toJSONString method will be
* called. Otherwise, the value's toString method will be called, and the
* result will be quoted.
*
*
* Warning: This method assumes that the data structure is acyclical.
*
* @param value
* The value to be serialized.
* @return a printable, displayable, transmittable representation of the
* object, beginning with { (left
* brace) and ending with } (right
* brace).
* @throws JSONException
* If the value is or contains an invalid number.
*/
public static String valueToString(Object value) throws JSONException {
if (value == null || value.equals(null)) {
return "null";
}
if (value instanceof JSONString) {
Object object;
try {
object = ((JSONString) value).toJSONString();
} catch (Exception e) {
throw new JSONException(e);
}
if (object instanceof String) {
return (String) object;
}
throw new JSONException("Bad value from toJSONString: " + object);
}
if (value instanceof Number) {
return numberToString((Number) value);
}
if (value instanceof Boolean || value instanceof JSONObject
|| value instanceof JSONArray) {
return value.toString();
}
if (value instanceof Map) {
return new JSONObject((Map