Summary: Constants | Ctors | Methods | Inherited Methods | [Expand All]

public class

JSONObject

extends Object

java.lang.Object
↳	org.json.JSONObject

Class Overview

A modifiable set of name/value mappings. Names are unique, non-null strings. Values may be any mix of JSONObjects, JSONArrays, Strings, Booleans, Integers, Longs, Doubles or NULL. Values may not be null, NaNs, infinities, or of any type not listed here.

This class can coerce values to another type when requested.

When the requested type is a boolean, strings will be coerced using valueOf(String).
When the requested type is a double, other Number types will be coerced using doubleValue. Strings that can be coerced using valueOf(String) will be.
When the requested type is an int, other Number types will be coerced using intValue. Strings that can be coerced using valueOf(String) will be, and then cast to int.
When the requested type is a long, other Number types will be coerced using longValue. Strings that can be coerced using valueOf(String) will be, and then cast to long. This two-step conversion is lossy for very large values. For example, the string "9223372036854775806" yields the long 9223372036854775807.
When the requested type is a String, other non-null values will be coerced using valueOf(Object). Although null cannot be coerced, the sentinel value NULL is coerced to the string "null".

This class can look up both mandatory and optional values:

Use getType() to retrieve a mandatory value. This fails with a JSONException if the requested name has no value or if the value cannot be coerced to the requested type.
Use optType() to retrieve an optional value. This returns a system- or user-supplied default if the requested name has no value or if the value cannot be coerced to the requested type.

Warning: this class represents null in two incompatible ways: the standard Java null reference, and the sentinel value NULL. In particular, calling put(name, null) removes the named entry from the object but put(name, JSONObject.NULL) stores an entry whose value is JSONObject.NULL.

Instances of this class are not thread safe. Although this class is nonfinal, it was not designed for inheritance and should not be subclassed. In particular, self-use by overridable methods is not specified. See Effective Java Item 17, "Design and Document or inheritance or else prohibit it" for further information.

Summary

Constants
Object	NULL	A sentinel value used to explicitly define a name with no value.

Public Constructors
	JSONObject() Creates a `JSONObject` with no name/value mappings.
	JSONObject(Map copyFrom) Creates a new `JSONObject` by copying all name/value mappings from the given map.
	JSONObject(JSONTokener readFrom) Creates a new `JSONObject` with name/value mappings from the next object in the tokener.
	JSONObject(String json) Creates a new `JSONObject` with name/value mappings from the JSON string.
	JSONObject(JSONObject copyFrom, String[] names) Creates a new `JSONObject` by copying mappings for the listed names from the given object.

Public Methods
JSONObject	accumulate(String name, Object value) Appends `value` to the array already mapped to `name`.
Object	get(String name) Returns the value mapped by `name`.
boolean	getBoolean(String name) Returns the value mapped by `name` if it exists and is a boolean or can be coerced to a boolean.
double	getDouble(String name) Returns the value mapped by `name` if it exists and is a double or can be coerced to a double.
int	getInt(String name) Returns the value mapped by `name` if it exists and is an int or can be coerced to an int.
JSONArray	getJSONArray(String name) Returns the value mapped by `name` if it exists and is a `JSONArray`.
JSONObject	getJSONObject(String name) Returns the value mapped by `name` if it exists and is a `JSONObject`.
long	getLong(String name) Returns the value mapped by `name` if it exists and is a long or can be coerced to a long.
String	getString(String name) Returns the value mapped by `name` if it exists, coercing it if necessary.
boolean	has(String name) Returns true if this object has a mapping for `name`.
boolean	isNull(String name) Returns true if this object has no mapping for `name` or if it has a mapping whose value is `NULL`.
Iterator	keys() Returns an iterator of the `String` names in this object.
int	length() Returns the number of name/value mappings in this object.
JSONArray	names() Returns an array containing the string names in this object.
static String	numberToString(Number number) Encodes the number as a JSON string.
Object	opt(String name) Returns the value mapped by `name`, or null if no such mapping exists.
boolean	optBoolean(String name) Returns the value mapped by `name` if it exists and is a boolean or can be coerced to a boolean.
boolean	optBoolean(String name, boolean fallback) Returns the value mapped by `name` if it exists and is a boolean or can be coerced to a boolean.
double	optDouble(String name) Returns the value mapped by `name` if it exists and is a double or can be coerced to a double.
double	optDouble(String name, double fallback) Returns the value mapped by `name` if it exists and is a double or can be coerced to a double.
int	optInt(String name, int fallback) Returns the value mapped by `name` if it exists and is an int or can be coerced to an int.
int	optInt(String name) Returns the value mapped by `name` if it exists and is an int or can be coerced to an int.
JSONArray	optJSONArray(String name) Returns the value mapped by `name` if it exists and is a `JSONArray`.
JSONObject	optJSONObject(String name) Returns the value mapped by `name` if it exists and is a `JSONObject`.
long	optLong(String name, long fallback) Returns the value mapped by `name` if it exists and is a long or can be coerced to a long.
long	optLong(String name) Returns the value mapped by `name` if it exists and is a long or can be coerced to a long.
String	optString(String name, String fallback) Returns the value mapped by `name` if it exists, coercing it if necessary.
String	optString(String name) Returns the value mapped by `name` if it exists, coercing it if necessary.
JSONObject	put(String name, boolean value) Maps `name` to `value`, clobbering any existing name/value mapping with the same name.
JSONObject	put(String name, double value) Maps `name` to `value`, clobbering any existing name/value mapping with the same name.
JSONObject	put(String name, Object value) Maps `name` to `value`, clobbering any existing name/value mapping with the same name.
JSONObject	put(String name, int value) Maps `name` to `value`, clobbering any existing name/value mapping with the same name.
JSONObject	put(String name, long value) Maps `name` to `value`, clobbering any existing name/value mapping with the same name.
JSONObject	putOpt(String name, Object value) Equivalent to `put(name, value)` when both parameters are non-null; does nothing otherwise.
static String	quote(String data) Encodes `data` as a JSON string.
Object	remove(String name) Removes the named mapping if it exists; does nothing otherwise.
JSONArray	toJSONArray(JSONArray names) Returns an array with the values corresponding to `names`.
String	toString() Encodes this object as a compact JSON string, such as: {"query":"Pizza","locations":[94043,90210]}
String	toString(int indentSpaces) Encodes this object as a human readable JSON string for debugging, such as: { "query": "Pizza", "locations": [ 94043, 90210 ] }

[Expand]

Inherited Methods

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Is called before the object's memory is being reclaimed by the VM.
final Class<? extends Object>	getClass() Returns the unique instance of `Class` which represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.

Constants

public static final Object NULL

Since: API Level 1

A sentinel value used to explicitly define a name with no value. Unlike null, names with this value:

show up in the names() array
show up in the keys() iterator
return true for has(String)
do not throw on get(String)
are included in the encoded JSON string.

This value violates the general contract of equals(Object) by returning true when compared to null. Its toString() method returns "null".

Public Constructors

public JSONObject ()

Since: API Level 1

Creates a JSONObject with no name/value mappings.

public JSONObject (Map copyFrom)

Since: API Level 1

Creates a new JSONObject by copying all name/value mappings from the given map.

Parameters

copyFrom	a map whose keys are of type `String` and whose values are of supported types.

Throws

NullPointerException	if any of the map's keys are null.

public JSONObject (JSONTokener readFrom)

Since: API Level 1

Creates a new JSONObject with name/value mappings from the next object in the tokener.

Parameters

readFrom	a tokener whose nextValue() method will yield a `JSONObject`.

Throws

JSONException	if the parse fails or doesn't yield a `JSONObject`.

public JSONObject (String json)

Since: API Level 1

Creates a new JSONObject with name/value mappings from the JSON string.

Parameters

json	a JSON-encoded string containing an object.

Throws

JSONException	if the parse fails or doesn't yield a `JSONObject`.

public JSONObject (JSONObject copyFrom, String[] names)

Since: API Level 1

Creates a new JSONObject by copying mappings for the listed names from the given object. Names that aren't present in copyFrom will be skipped.

Throws

JSONException

Public Methods

public JSONObject accumulate (String name, Object value)

Since: API Level 1

Appends value to the array already mapped to name. If this object has no mapping for name, this inserts a new mapping. If the mapping exists but its value is not an array, the existing and new values are inserted in order into a new array which is itself mapped to name. In aggregate, this allows values to be added to a mapping one at a time.

Parameters

value	a `JSONObject`, `JSONArray`, String, Boolean, Integer, Long, Double, `NULL` or null. May not be `NaNs` or `infinities`.

Throws

JSONException

public Object get (String name)

Since: API Level 1

Returns the value mapped by name.

Throws

JSONException	if no such mapping exists.

public boolean getBoolean (String name)

Since: API Level 1

Returns the value mapped by name if it exists and is a boolean or can be coerced to a boolean.

Throws

JSONException	if the mapping doesn't exist or cannot be coerced to a boolean.

public double getDouble (String name)

Since: API Level 1

Returns the value mapped by name if it exists and is a double or can be coerced to a double.

Throws

JSONException	if the mapping doesn't exist or cannot be coerced to a double.

public int getInt (String name)

Since: API Level 1

Returns the value mapped by name if it exists and is an int or can be coerced to an int.

Throws

JSONException	if the mapping doesn't exist or cannot be coerced to an int.

public JSONArray getJSONArray (String name)

Since: API Level 1

Returns the value mapped by name if it exists and is a JSONArray.

Throws

JSONException	if the mapping doesn't exist or is not a `JSONArray`.

public JSONObject getJSONObject (String name)

Since: API Level 1

Returns the value mapped by name if it exists and is a JSONObject.

Throws

JSONException	if the mapping doesn't exist or is not a `JSONObject`.

public long getLong (String name)

Since: API Level 1

Returns the value mapped by name if it exists and is a long or can be coerced to a long.

Throws

JSONException	if the mapping doesn't exist or cannot be coerced to a long.

public String getString (String name)

Since: API Level 1

Returns the value mapped by name if it exists, coercing it if necessary.

Throws

JSONException	if no such mapping exists.

public boolean has (String name)

Since: API Level 1

Returns true if this object has a mapping for name. The mapping may be NULL.

public boolean isNull (String name)

Since: API Level 1

Returns true if this object has no mapping for name or if it has a mapping whose value is NULL.

public Iterator keys ()

Since: API Level 1

Returns an iterator of the String names in this object. The returned iterator supports remove, which will remove the corresponding mapping from this object. If this object is modified after the iterator is returned, the iterator's behavior is undefined. The order of the keys is undefined.

public int length ()

Since: API Level 1

Returns the number of name/value mappings in this object.

public JSONArray names ()

Since: API Level 1

Returns an array containing the string names in this object. This method returns null if this object contains no mappings.

public static String numberToString (Number number)

Since: API Level 1

Encodes the number as a JSON string.

Parameters

number	a finite value. May not be `NaNs` or `infinities`.

Throws

JSONException

public Object opt (String name)

Since: API Level 1

Returns the value mapped by name, or null if no such mapping exists.

public boolean optBoolean (String name)

Since: API Level 1

Returns the value mapped by name if it exists and is a boolean or can be coerced to a boolean. Returns false otherwise.

public boolean optBoolean (String name, boolean fallback)

Since: API Level 1

Returns the value mapped by name if it exists and is a boolean or can be coerced to a boolean. Returns fallback otherwise.

public double optDouble (String name)

Since: API Level 1

Returns the value mapped by name if it exists and is a double or can be coerced to a double. Returns NaN otherwise.

public double optDouble (String name, double fallback)

Since: API Level 1

Returns the value mapped by name if it exists and is a double or can be coerced to a double. Returns fallback otherwise.

public int optInt (String name, int fallback)

Since: API Level 1

Returns the value mapped by name if it exists and is an int or can be coerced to an int. Returns fallback otherwise.

public int optInt (String name)

Since: API Level 1

Returns the value mapped by name if it exists and is an int or can be coerced to an int. Returns 0 otherwise.

public JSONArray optJSONArray (String name)

Since: API Level 1

Returns the value mapped by name if it exists and is a JSONArray. Returns null otherwise.

public JSONObject optJSONObject (String name)

Since: API Level 1

Returns the value mapped by name if it exists and is a JSONObject. Returns null otherwise.

public long optLong (String name, long fallback)

Since: API Level 1

Returns the value mapped by name if it exists and is a long or can be coerced to a long. Returns fallback otherwise.

public long optLong (String name)

Since: API Level 1

Returns the value mapped by name if it exists and is a long or can be coerced to a long. Returns 0 otherwise.

public String optString (String name, String fallback)

Since: API Level 1

Returns the value mapped by name if it exists, coercing it if necessary. Returns fallback if no such mapping exists.

public String optString (String name)

Since: API Level 1

Returns the value mapped by name if it exists, coercing it if necessary. Returns the empty string if no such mapping exists.

public JSONObject put (String name, boolean value)

Since: API Level 1

Maps name to value, clobbering any existing name/value mapping with the same name.

Returns

this object.

Throws

JSONException

public JSONObject put (String name, double value)

Since: API Level 1

Maps name to value, clobbering any existing name/value mapping with the same name.

Parameters

value	a finite value. May not be `NaNs` or `infinities`.

Returns

this object.

Throws

JSONException

public JSONObject put (String name, Object value)

Since: API Level 1

Maps name to value, clobbering any existing name/value mapping with the same name. If the value is null, any existing mapping for name is removed.

Parameters

value	a `JSONObject`, `JSONArray`, String, Boolean, Integer, Long, Double, `NULL`, or `null`. May not be `NaNs` or `infinities`.

Returns

this object.

Throws

JSONException

public JSONObject put (String name, int value)

Since: API Level 1

Maps name to value, clobbering any existing name/value mapping with the same name.

Returns

this object.

Throws

JSONException

public JSONObject put (String name, long value)

Since: API Level 1

Maps name to value, clobbering any existing name/value mapping with the same name.

Returns

this object.

Throws

JSONException

public JSONObject putOpt (String name, Object value)

Since: API Level 1

Equivalent to put(name, value) when both parameters are non-null; does nothing otherwise.

Throws

JSONException

public static String quote (String data)

Since: API Level 1

Encodes data as a JSON string. This applies quotes and any necessary character escaping.

Parameters

data	the string to encode. Null will be interpreted as an empty string.

public Object remove (String name)

Since: API Level 1

Removes the named mapping if it exists; does nothing otherwise.

Returns

the value previously mapped by name, or null if there was no such mapping.

public JSONArray toJSONArray (JSONArray names)

Since: API Level 1

Returns an array with the values corresponding to names. The array contains null for names that aren't mapped. This method returns null if names is either null or empty.

Throws

JSONException

public String toString ()

Since: API Level 1

Encodes this object as a compact JSON string, such as:

{"query":"Pizza","locations":[94043,90210]}

Returns

a printable representation of this object.

public String toString (int indentSpaces)

Since: API Level 1

Encodes this object as a human readable JSON string for debugging, such as:

 {
     "query": "Pizza",
     "locations": [
         94043,
         90210
     ]
 }

Parameters

indentSpaces	the number of spaces to indent for each level of nesting.

Throws

JSONException

Classes

Exceptions

JSONObject

Class Overview

Summary

Constants

public static final Object NULL

Public Constructors

public JSONObject ()

public JSONObject (Map copyFrom)

Parameters

Throws

public JSONObject (JSONTokener readFrom)

Parameters

Throws

public JSONObject (String json)

Parameters

Throws

public JSONObject (JSONObject copyFrom, String[] names)

Throws

Public Methods

public JSONObject accumulate (String name, Object value)

Parameters

Throws

public Object get (String name)

Throws

public boolean getBoolean (String name)

Throws

public double getDouble (String name)

Throws

public int getInt (String name)

Throws

public JSONArray getJSONArray (String name)

Throws

public JSONObject getJSONObject (String name)

Throws

public long getLong (String name)

Throws

public String getString (String name)

Throws

public boolean has (String name)

public boolean isNull (String name)

public Iterator keys ()

public int length ()

public JSONArray names ()

public static String numberToString (Number number)

Parameters

Throws

public Object opt (String name)

public boolean optBoolean (String name)

public boolean optBoolean (String name, boolean fallback)

public double optDouble (String name)

public double optDouble (String name, double fallback)

public int optInt (String name, int fallback)

public int optInt (String name)

public JSONArray optJSONArray (String name)

public JSONObject optJSONObject (String name)

public long optLong (String name, long fallback)

public long optLong (String name)

public String optString (String name, String fallback)

public String optString (String name)

public JSONObject put (String name, boolean value)

Returns

Throws

public JSONObject put (String name, double value)

Parameters

Returns

Throws

public JSONObject put (String name, Object value)

Parameters

Returns

Throws

public JSONObject put (String name, int value)

Returns

Throws

public JSONObject put (String name, long value)

Returns

Throws

public JSONObject putOpt (String name, Object value)

Throws