Public Member Functions
	JSONObject ()

	JSONObject (JSONObject jo, String[] names)

	JSONObject (JSONTokener x) throws JSONException

	JSONObject (Map map)

	JSONObject (Object bean)

	JSONObject (Object object, String names[])

	JSONObject (String source) throws JSONException

	JSONObject (String baseName, Locale locale) throws JSONException

JSONObject	accumulate (String key, Object value) throws JSONException

JSONObject	append (String key, Object value) throws JSONException

Object	get (String key) throws JSONException

boolean	getBoolean (String key) throws JSONException

double	getDouble (String key) throws JSONException

int	getInt (String key) throws JSONException

JSONArray	getJSONArray (String key) throws JSONException

JSONObject	getJSONObject (String key) throws JSONException

long	getLong (String key) throws JSONException

String	getString (String key) throws JSONException

boolean	has (String key)

JSONObject	increment (String key) throws JSONException

boolean	isNull (String key)

Iterator	keys ()

Set	keySet ()

int	length ()

JSONArray	names ()

Object	opt (String key)

boolean	optBoolean (String key)

boolean	optBoolean (String key, boolean defaultValue)

double	optDouble (String key)

double	optDouble (String key, double defaultValue)

int	optInt (String key)

int	optInt (String key, int defaultValue)

JSONArray	optJSONArray (String key)

JSONObject	optJSONObject (String key)

long	optLong (String key)

long	optLong (String key, long defaultValue)

String	optString (String key)

String	optString (String key, String defaultValue)

JSONObject	put (String key, boolean value) throws JSONException

JSONObject	put (String key, Collection value) throws JSONException

JSONObject	put (String key, double value) throws JSONException

JSONObject	put (String key, int value) throws JSONException

JSONObject	put (String key, long value) throws JSONException

JSONObject	put (String key, Map value) throws JSONException

JSONObject	put (String key, Object value) throws JSONException

JSONObject	putOnce (String key, Object value) throws JSONException

JSONObject	putOpt (String key, Object value) throws JSONException

Object	remove (String key)

JSONArray	toJSONArray (JSONArray names) throws JSONException

String	toString ()

String	toString (int indentFactor) throws JSONException

Writer	write (Writer writer) throws JSONException

Static Public Member Functions
static String	doubleToString (double d)

static String []	getNames (JSONObject jo)

static String []	getNames (Object object)

static String	numberToString (Number number) throws JSONException

static String	quote (String string)

static Writer	quote (String string, Writer w) throws IOException

static Object	stringToValue (String string)

static void	testValidity (Object o) throws JSONException

static String	valueToString (Object value) throws JSONException

static Object	wrap (Object object)

Static Public Attributes
static final Object	NULL = new Null()

Package Functions
Writer	write (Writer writer, int indentFactor, int indent) throws JSONException

Static Package Functions
static final Writer	writeValue (Writer writer, Object value, int indentFactor, int indent) throws JSONException, IOException

static final void	indent (Writer writer, int indent) throws IOException

Detailed Description

A JSONObject is an unordered collection of name/value pairs. Its external form is a string wrapped in curly braces with colons between the names and values, and commas between the values and names. The internal form is an object having 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:

An extra , (comma) may appear just before the closing brace.
Strings may be quoted with ' (single quote).
Strings do not need to be quoted at all if they do not begin with a quote or single quote, and if they do not contain leading or trailing spaces, and if they do not contain any of these characters: { } [ ] / \ : , # and if they do not look like numbers and if they are not the reserved words true, false, or null.

Author: JSON.org

Version: 2013-06-17

Constructor & Destructor Documentation

◆ JSONObject() [1/8]

JSONObject ( )

Construct an empty JSONObject.

◆ JSONObject() [2/8]

JSONObject	(	JSONObject	jo,
		String []	names
	)

Construct a JSONObject from a subset of another JSONObject. An array of strings is used to identify the keys that should be copied. Missing keys are ignored.

Parameters

jo	A JSONObject.
names	An array of strings.

Exceptions

JSONException
JSONException	If a value is a non-finite number or if a name is duplicated.

◆ JSONObject() [3/8]

JSONObject ( JSONTokener x ) throws JSONException

Construct a JSONObject from a JSONTokener.

Parameters

x	A JSONTokener object containing the source string.

Exceptions

JSONException If there is a syntax error in the source string or a duplicated key.

◆ JSONObject() [4/8]

JSONObject ( Map map )

Construct a JSONObject from a Map.

Parameters

map	A map object that can be used to initialize the contents of the JSONObject.

Exceptions

JSONException

◆ JSONObject() [5/8]

JSONObject ( Object bean )

Construct a JSONObject from an Object using bean getters. It reflects on all of the public methods of the object. For each of the methods with no parameters and a name starting with "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".

Parameters

bean	An object that has getter methods that should be used to make a JSONObject.

◆ JSONObject() [6/8]

JSONObject	(	Object	object,
		String	names[]
	)

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.

Parameters

object	An object that has fields that should be used to make a JSONObject.
names	An array of strings, the names of the fields to be obtained from the object.

◆ JSONObject() [7/8]

JSONObject ( String source ) throws JSONException

Construct a JSONObject from a source JSON text string. This is the most commonly used JSONObject constructor.

Parameters

source A string beginning with { (left brace) and ending with } (right brace).

Exceptions

JSONException If there is a syntax error in the source string or a duplicated key.

◆ JSONObject() [8/8]

JSONObject	(	String	baseName,
		Locale	locale
	)		throws JSONException

Construct a JSONObject from a ResourceBundle.

Parameters

baseName	The ResourceBundle base name.
locale	The Locale to load the ResourceBundle for.

Exceptions

JSONException If any JSONExceptions are detected.

Member Function Documentation

◆ accumulate()

JSONObject accumulate	(	String	key,
		Object	value
	)		throws JSONException

Accumulate values under a key. It is similar to the put method except that if there is already an object stored under the key then a JSONArray is stored under the key to hold all of the accumulated values. If there is already a JSONArray, then the new value is appended to it. In contrast, the put method replaces the previous value.

If only one value is accumulated that is not a JSONArray, then the result will be the same as using put. But if multiple values are accumulated, then the result will be like append.

Parameters

key	A key string.
value	An object to be accumulated under the key.

Returns: this.

Exceptions

JSONException If the value is an invalid number or if the key is null.

◆ append()

JSONObject append	(	String	key,
		Object	value
	)		throws JSONException

Append values to the array under a key. If the key does not exist in the JSONObject, then the key is put in the JSONObject with its value being a JSONArray containing the value parameter. If the key was already associated with a JSONArray, then the value parameter is appended to it.

Parameters

key	A key string.
value	An object to be accumulated under the key.

Returns: this.

Exceptions

JSONException If the key is null or if the current value associated with the key is not a JSONArray.

◆ doubleToString()

static String doubleToString ( double d )

static

Produce a string from a double. The string "null" will be returned if the number is not finite.

Parameters

d A double.

Returns: A String.

◆ get()

Object get ( String key ) throws JSONException

Get the value object associated with a key.

Parameters

key	A key string.

Returns: The object associated with the key.

Exceptions

JSONException if the key is not found.

◆ getBoolean()

boolean getBoolean ( String key ) throws JSONException

Get the boolean value associated with a key.

Parameters

key	A key string.

Returns: The truth.

Exceptions

JSONException if the value is not a Boolean or the String "true" or "false".

◆ getDouble()

double getDouble ( String key ) throws JSONException

Get the double value associated with a key.

Parameters

key	A key string.

Returns: The numeric value.

Exceptions

JSONException if the key is not found or if the value is not a Number object and cannot be converted to a number.

◆ getInt()

int getInt ( String key ) throws JSONException

Get the int value associated with a key.

Parameters

key	A key string.

Returns: The integer value.

Exceptions

JSONException if the key is not found or if the value cannot be converted to an integer.

◆ getJSONArray()

JSONArray getJSONArray ( String key ) throws JSONException

Get the JSONArray value associated with a key.

Parameters

key	A key string.

Returns: A JSONArray which is the value.

Exceptions

JSONException if the key is not found or if the value is not a JSONArray.

◆ getJSONObject()

JSONObject getJSONObject ( String key ) throws JSONException

Get the JSONObject value associated with a key.

Parameters

key	A key string.

Returns: A JSONObject which is the value.

Exceptions

JSONException if the key is not found or if the value is not a JSONObject.

◆ getLong()

long getLong ( String key ) throws JSONException

Get the long value associated with a key.

Parameters

key	A key string.

Returns: The long value.

Exceptions

JSONException if the key is not found or if the value cannot be converted to a long.

◆ getNames() [1/2]

static String [] getNames ( JSONObject jo )

static

Get an array of field names from a JSONObject.

Returns: An array of field names, or null if there are no names.

◆ getNames() [2/2]

static String [] getNames ( Object object )

static

Get an array of field names from an Object.

Returns: An array of field names, or null if there are no names.

◆ getString()

String getString ( String key ) throws JSONException

Get the string associated with a key.

Parameters

key	A key string.

Returns: A string which is the value.

Exceptions

JSONException if there is no string value for the key.

◆ has()

boolean has ( String key )

Determine if the JSONObject contains a specific key.

Parameters

key	A key string.

Returns: true if the key exists in the JSONObject.

◆ increment()

JSONObject increment ( String key ) throws JSONException

Increment a property of a JSONObject. If there is no such property, create one with a value of 1. If there is such a property, and if it is an Integer, Long, Double, or Float, then add one to it.

Parameters

key	A key string.

Returns: this.

Exceptions

JSONException If there is already a property with this name that is not an Integer, Long, Double, or Float.

◆ indent()

static final void indent	(	Writer	writer,
		int	indent
	)		throws IOException

staticpackage

◆ isNull()

boolean isNull ( String key )

Determine if the value associated with the key is null or if there is no value.

Parameters

key	A key string.

Returns: true if there is no value associated with the key or if the value is the JSONObject.NULL object.

◆ keys()

Iterator keys ( )

Get an enumeration of the keys of the JSONObject.

Returns: An iterator of the keys.

◆ keySet()

Set keySet ( )

Get a set of keys of the JSONObject.

Returns: A keySet.

◆ length()

int length ( )

Get the number of keys stored in the JSONObject.

Returns: The number of keys in the JSONObject.

◆ names()

JSONArray names ( )

Produce a JSONArray containing the names of the elements of this JSONObject.

Returns: A JSONArray containing the key strings, or null if the JSONObject is empty.

◆ numberToString()

static String numberToString ( Number number ) throws JSONException

static

Produce a string from a Number.

Parameters

number A Number

Returns: A String.

Exceptions

JSONException If n is a non-finite number.

◆ opt()

Object opt ( String key )

Get an optional value associated with a key.

Parameters

key	A key string.

Returns: An object which is the value, or null if there is no value.

◆ optBoolean() [1/2]

boolean optBoolean ( String key )

Get an optional boolean associated with a key. It returns false if there is no such key, or if the value is not Boolean.TRUE or the String "true".

Parameters

key	A key string.

Returns: The truth.

◆ optBoolean() [2/2]

boolean optBoolean	(	String	key,
		boolean	defaultValue
	)

Get an optional boolean associated with a key. It returns the defaultValue if there is no such key, or if it is not a Boolean or the String "true" or "false" (case insensitive).

Parameters

key	A key string.
defaultValue	The default.

Returns: The truth.

◆ optDouble() [1/2]

double optDouble ( String key )

Get an optional double associated with a key, or NaN if there is no such key or if its value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters

key	A string which is the key.

Returns: An object which is the value.

◆ optDouble() [2/2]

double optDouble	(	String	key,
		double	defaultValue
	)

Get an optional double associated with a key, or the defaultValue if there is no such key or if its value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters

key	A key string.
defaultValue	The default.

Returns: An object which is the value.

◆ optInt() [1/2]

int optInt ( String key )

Get an optional int value associated with a key, or zero if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters

key	A key string.

Returns: An object which is the value.

◆ optInt() [2/2]

int optInt	(	String	key,
		int	defaultValue
	)

Get an optional int value associated with a key, or the default if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters

key	A key string.
defaultValue	The default.

Returns: An object which is the value.

◆ optJSONArray()

JSONArray optJSONArray ( String key )

Get an optional JSONArray associated with a key. It returns null if there is no such key, or if its value is not a JSONArray.

Parameters

key	A key string.

Returns: A JSONArray which is the value.

◆ optJSONObject()

JSONObject optJSONObject ( String key )

Get an optional JSONObject associated with a key. It returns null if there is no such key, or if its value is not a JSONObject.

Parameters

key	A key string.

Returns: A JSONObject which is the value.

◆ optLong() [1/2]

long optLong ( String key )

Get an optional long value associated with a key, or zero if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters

key	A key string.

Returns: An object which is the value.

◆ optLong() [2/2]

long optLong	(	String	key,
		long	defaultValue
	)

Get an optional long value associated with a key, or the default if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters

key	A key string.
defaultValue	The default.

Returns: An object which is the value.

◆ optString() [1/2]

String optString ( String key )

Get an optional string associated with a key. It returns an empty string if there is no such key. If the value is not a string and is not null, then it is converted to a string.

Parameters

key	A key string.

Returns: A string which is the value.

◆ optString() [2/2]

String optString	(	String	key,
		String	defaultValue
	)

Get an optional string associated with a key. It returns the defaultValue if there is no such key.

Parameters

key	A key string.
defaultValue	The default.

Returns: A string which is the value.

◆ put() [1/7]

JSONObject put	(	String	key,
		boolean	value
	)		throws JSONException

Put a key/boolean pair in the JSONObject.

Parameters

key	A key string.
value	A boolean which is the value.

Returns: this.

Exceptions

JSONException If the key is null.

◆ put() [2/7]

JSONObject put	(	String	key,
		Collection	value
	)		throws JSONException

Put a key/value pair in the JSONObject, where the value will be a JSONArray which is produced from a Collection.

Parameters

key	A key string.
value	A Collection value.

Returns: this.

Exceptions

JSONException

◆ put() [3/7]

JSONObject put	(	String	key,
		double	value
	)		throws JSONException

Put a key/double pair in the JSONObject.

Parameters

key	A key string.
value	A double which is the value.

Returns: this.

Exceptions

JSONException If the key is null or if the number is invalid.

◆ put() [4/7]

JSONObject put	(	String	key,
		int	value
	)		throws JSONException

Put a key/int pair in the JSONObject.

Parameters

key	A key string.
value	An int which is the value.

Returns: this.

Exceptions

JSONException If the key is null.

◆ put() [5/7]

JSONObject put	(	String	key,
		long	value
	)		throws JSONException

Put a key/long pair in the JSONObject.

Parameters

key	A key string.
value	A long which is the value.

Returns: this.

Exceptions

JSONException If the key is null.

◆ put() [6/7]

JSONObject put	(	String	key,
		Map	value
	)		throws JSONException

Put a key/value pair in the JSONObject, where the value will be a JSONObject which is produced from a Map.

Parameters

key	A key string.
value	A Map value.

Returns: this.

Exceptions

JSONException

◆ put() [7/7]

JSONObject put	(	String	key,
		Object	value
	)		throws JSONException

Put a key/value pair in the JSONObject. If the value is null, then the key will be removed from the JSONObject if it is present.

Parameters

key	A key string.
value	An object which is the value. It should be of one of these types: Boolean, Double, Integer, JSONArray, JSONObject, Long, String, or the JSONObject.NULL object.

Returns: this.

Exceptions

JSONException If the value is non-finite number or if the key is null.

◆ putOnce()

JSONObject putOnce	(	String	key,
		Object	value
	)		throws JSONException

Put a key/value pair in the JSONObject, but only if the key and the value are both non-null, and only if there is not already a member with that name.

Parameters

key
value

Returns: his.

Exceptions

JSONException if the key is a duplicate

◆ putOpt()

JSONObject putOpt	(	String	key,
		Object	value
	)		throws JSONException

Put a key/value pair in the JSONObject, but only if the key and the value are both non-null.

Parameters

key	A key string.
value	An object which is the value. It should be of one of these types: Boolean, Double, Integer, JSONArray, JSONObject, Long, String, or the JSONObject.NULL object.

Returns: this.

Exceptions

JSONException If the value is a non-finite number.

◆ quote() [1/2]

static String quote ( String string )

static

Produce a string in double quotes with backslash sequences in all the right places. A backslash will be inserted within </, producing <\/, allowing JSON text to be delivered in HTML. In JSON text, a string cannot contain a control character or an unescaped quote or backslash.

Parameters

string A String

Returns: A String correctly formatted for insertion in a JSON text.

◆ quote() [2/2]

static Writer quote	(	String	string,
		Writer	w
	)		throws IOException

static

◆ remove()

Object remove ( String key )

Remove a name and its value, if present.

Parameters

key	The name to be removed.

Returns: The value that was associated with the name, or null if there was no value.

◆ stringToValue()

static Object stringToValue ( String string )

static

Try to convert a string into a number, boolean, or null. If the string can't be converted, return the string.

Parameters

string A String.

Returns: A simple JSON value.

◆ testValidity()

static void testValidity ( Object o ) throws JSONException

static

Throw an exception if the object is a NaN or infinite number.

Parameters

o	The object to test.

Exceptions

JSONException If o is a non-finite number.

◆ toJSONArray()

JSONArray toJSONArray ( JSONArray names ) throws JSONException

Produce a JSONArray containing the values of the members of this JSONObject.

Parameters

names A JSONArray containing a list of key strings. This determines the sequence of the values in the result.

Returns: A JSONArray of values.

Exceptions

JSONException If any of the values are non-finite numbers.

◆ toString() [1/2]

String toString ( )

Make a JSON text of this JSONObject. For compactness, no whitespace is added. If this would not result in a syntactically correct JSON text, then null will be returned instead.

Warning: This method assumes that the data structure is acyclical.

Returns: a printable, displayable, portable, transmittable representation of the object, beginning with { (left brace) and ending with } (right brace).

◆ toString() [2/2]

String toString ( int indentFactor ) throws JSONException

Make a prettyprinted JSON text of this JSONObject.

Warning: This method assumes that the data structure is acyclical.

Parameters

indentFactor The number of spaces to add to each level of indentation.

Returns: a printable, displayable, portable, transmittable representation of the object, beginning with { (left brace) and ending with } (right brace).

Exceptions

JSONException If the object contains an invalid number.

◆ valueToString()

static String valueToString ( Object value ) throws JSONException

static

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.

Parameters

value The value to be serialized.

Returns: a printable, displayable, transmittable representation of the object, beginning with { (left brace) and ending with } (right brace).

Exceptions

JSONException If the value is or contains an invalid number.

◆ wrap()

static Object wrap ( Object object )

static

Wrap an object, if necessary. If the object is null, return the NULL object. If it is an array or collection, wrap it in a JSONArray. If it is a map, wrap it in a JSONObject. If it is a standard property (Double, String, et al) then it is already wrapped. Otherwise, if it comes from one of the java packages, turn it into a string. And if it doesn't, try to wrap it in a JSONObject. If the wrapping fails, then null is returned.

Parameters

object The object to wrap

Returns: The wrapped value

◆ write() [1/2]

Writer write ( Writer writer ) throws JSONException

Write the contents of the JSONObject as JSON text to a writer. For compactness, no whitespace is added.

Warning: This method assumes that the data structure is acyclical.

Returns: The writer.

Exceptions

JSONException

◆ write() [2/2]

Writer write	(	Writer	writer,
		int	indentFactor,
		int	indent
	)		throws JSONException

package

Write the contents of the JSONObject as JSON text to a writer. For compactness, no whitespace is added.

Warning: This method assumes that the data structure is acyclical.

Returns: The writer.

Exceptions

JSONException

◆ writeValue()

static final Writer writeValue	(	Writer	writer,
		Object	value,
		int	indentFactor,
		int	indent
	)		throws JSONException, IOException

staticpackage

Member Data Documentation

◆ NULL

final Object NULL = new Null()

static

It is sometimes more convenient and less ambiguous to have a NULL object than to use Java's null value. JSONObject.NULL.equals(null) returns true. JSONObject.NULL.toString() returns "null".

Public Member Functions

Static Public Member Functions

Static Public Attributes

Package Functions

Static Package Functions

Detailed Description

Constructor & Destructor Documentation

◆ JSONObject() [1/8]

◆ JSONObject() [2/8]

◆ JSONObject() [3/8]

◆ JSONObject() [4/8]

◆ JSONObject() [5/8]

◆ JSONObject() [6/8]

◆ JSONObject() [7/8]

◆ JSONObject() [8/8]

Member Function Documentation

◆ accumulate()

◆ append()

◆ doubleToString()

◆ get()

◆ getBoolean()

◆ getDouble()

◆ getInt()

◆ getJSONArray()

◆ getJSONObject()

◆ getLong()

◆ getNames() [1/2]

◆ getNames() [2/2]

◆ getString()

◆ has()

◆ increment()

◆ indent()

◆ isNull()

◆ keys()

◆ keySet()

◆ length()

◆ names()

◆ numberToString()

◆ opt()

◆ optBoolean() [1/2]

◆ optBoolean() [2/2]

◆ optDouble() [1/2]

◆ optDouble() [2/2]

◆ optInt() [1/2]

◆ optInt() [2/2]

◆ optJSONArray()

◆ optJSONObject()

◆ optLong() [1/2]

◆ optLong() [2/2]

◆ optString() [1/2]

◆ optString() [2/2]

◆ put() [1/7]

◆ put() [2/7]

◆ put() [3/7]

◆ put() [4/7]

◆ put() [5/7]

◆ put() [6/7]

◆ put() [7/7]

◆ putOnce()

◆ putOpt()

◆ quote() [1/2]

◆ quote() [2/2]

◆ remove()

◆ stringToValue()

◆ testValidity()

◆ toJSONArray()

◆ toString() [1/2]

◆ toString() [2/2]

◆ valueToString()

◆ wrap()

◆ write() [1/2]

◆ write() [2/2]

◆ writeValue()

Member Data Documentation

◆ NULL