Added in API level 1

Summary: Fields | Ctors | Methods | Inherited Methods

JSONObject

public class JSONObject
extends Object

java.lang.Object
↳	org.json.JSONObject

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 a case-insensitive comparison to "true" and "false".
When the requested type is a double, other Number types will be coerced using doubleValue. Strings that can be coerced using Double.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 Double.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 Double.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 String.valueOf(Object). Although null cannot be coerced, the sentinel value JSONObject.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 overrideable methods is not specified. See Effective Java, 3rd edition Item 19, "Design and Document for inheritance or else prohibit it" for further information.

Summary

Fields
`public static final 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(String json)` Creates a new `JSONObject` with name/value mappings from the JSON string.
`JSONObject(Map<K, V> copyFrom)` Creates a new `JSONObject` by copying all name/value mappings from the given map.
`JSONObject(JSONObject copyFrom, String[] names)` Creates a new `JSONObject` by copying mappings for the listed names from the given object.
`JSONObject(JSONTokener readFrom)` Creates a new `JSONObject` with name/value mappings from the next object in the tokener.

Public methods
`JSONObject`	`accumulate(String name, Object value)` Appends `value` to the array already mapped to `name`.
`JSONObject`	`append(String name, Object value)` Appends values to the array mapped to `name`.
`Object`	`get(String name)` Returns the value mapped by `name`, or throws if no such mapping exists.
`boolean`	`getBoolean(String name)` Returns the value mapped by `name` if it exists and is a boolean or can be coerced to a boolean, or throws otherwise.
`double`	`getDouble(String name)` Returns the value mapped by `name` if it exists and is a double or can be coerced to a double, or throws otherwise.
`int`	`getInt(String name)` Returns the value mapped by `name` if it exists and is an int or can be coerced to an int, or throws otherwise.
`JSONArray`	`getJSONArray(String name)` Returns the value mapped by `name` if it exists and is a `JSONArray`, or throws otherwise.
`JSONObject`	`getJSONObject(String name)` Returns the value mapped by `name` if it exists and is a `JSONObject`, or throws otherwise.
`long`	`getLong(String name)` Returns the value mapped by `name` if it exists and is a long or can be coerced to a long, or throws otherwise.
`String`	`getString(String name)` Returns the value mapped by `name` if it exists, coercing it if necessary, or throws if no such mapping exists.
`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<String>`	`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, boolean fallback)` Returns the value mapped by `name` if it exists and is a boolean or can be coerced to a boolean, or `fallback` otherwise.
`boolean`	`optBoolean(String name)` Returns the value mapped by `name` if it exists and is a boolean or can be coerced to a boolean, or false otherwise.
`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, or `fallback` otherwise.
`double`	`optDouble(String name)` Returns the value mapped by `name` if it exists and is a double or can be coerced to a double, or `NaN` otherwise.
`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, or `fallback` otherwise.
`int`	`optInt(String name)` Returns the value mapped by `name` if it exists and is an int or can be coerced to an int, or 0 otherwise.
`JSONArray`	`optJSONArray(String name)` Returns the value mapped by `name` if it exists and is a `JSONArray`, or null otherwise.
`JSONObject`	`optJSONObject(String name)` Returns the value mapped by `name` if it exists and is a `JSONObject`, or null otherwise.
`long`	`optLong(String name)` Returns the value mapped by `name` if it exists and is a long or can be coerced to a long, or 0 otherwise.
`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, or `fallback` otherwise.
`String`	`optString(String name, String fallback)` Returns the value mapped by `name` if it exists, coercing it if necessary, or `fallback` if no such mapping exists.
`String`	`optString(String name)` Returns the value mapped by `name` if it exists, coercing it if necessary, or the empty string if no such mapping exists.
`JSONObject`	`put(String name, double value)` Maps `name` to `value`, clobbering any existing name/value mapping with the same name.
`JSONObject`	`put(String name, boolean 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`	`put(String name, Object 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 ] }
`static Object`	`wrap(Object o)` Wraps the given object if necessary.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Fields

NULL

Added in API level 1

public static final Object NULL

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(java.lang.String)
do not throw on get(java.lang.String)
are included in the encoded JSON string.

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

Public constructors

JSONObject

Added in API level 1

public JSONObject ()

Creates a JSONObject with no name/value mappings.

JSONObject

Added in API level 1

public JSONObject (String json)

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

Parameters
`json`	`String`: a JSON-encoded string containing an object.

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

JSONObject

Added in API level 1

public JSONObject (Map<K, V> copyFrom)

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

Parameters
`copyFrom`	`Map`: 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.

JSONObject

Added in API level 1

public JSONObject (JSONObject copyFrom, 
                String[] names)

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.

Parameters
`copyFrom`	`JSONObject`
`names`	`String`

Throws
`JSONException`

JSONObject

Added in API level 1

public JSONObject (JSONTokener readFrom)

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

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

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

Public methods

accumulate

Added in API level 1

public JSONObject accumulate (String name, 
                Object value)

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.

Note that append(java.lang.String, java.lang.Object) provides better semantics. In particular, the mapping for name will always be a JSONArray. Using accumulate will result in either a JSONArray or a mapping whose type is the type of value depending on the number of calls to it.

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

Returns
`JSONObject`

Throws
`JSONException`

append

Added in API level 33

public JSONObject append (String name, 
                Object value)

Appends values to the array mapped to name. A new JSONArray mapping for name will be inserted if no mapping exists. If the existing mapping for name is not a JSONArray, a JSONException will be thrown.

Parameters
`name`	`String`
`value`	`Object`

Returns
`JSONObject`

Throws
`JSONException`	if `name` is `null` or if the mapping for `name` is non-null and is not a `JSONArray`.

get

Added in API level 1

public Object get (String name)

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

Parameters
`name`	`String`

Returns
`Object`

Throws
`JSONException`	if no such mapping exists.

getBoolean

Added in API level 1

public boolean getBoolean (String name)

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

Parameters
`name`	`String`

Returns
`boolean`

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

getDouble

Added in API level 1

public double getDouble (String name)

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

Parameters
`name`	`String`

Returns
`double`

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

getInt

Added in API level 1

public int getInt (String name)

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

Parameters
`name`	`String`

Returns
`int`

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

getJSONArray

Added in API level 1

public JSONArray getJSONArray (String name)

Returns the value mapped by name if it exists and is a JSONArray, or throws otherwise.

Parameters
`name`	`String`

Returns
`JSONArray`

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

getJSONObject

Added in API level 1

public JSONObject getJSONObject (String name)

Returns the value mapped by name if it exists and is a JSONObject, or throws otherwise.

Parameters
`name`	`String`

Returns
`JSONObject`

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

getLong

Added in API level 1

public long getLong (String name)

Returns the value mapped by name if it exists and is a long or can be coerced to a long, or throws otherwise. Note that JSON represents numbers as doubles, so this is lossy; use strings to transfer numbers via JSON.

Parameters
`name`	`String`

Returns
`long`

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

getString

Added in API level 1

public String getString (String name)

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

Parameters
`name`	`String`

Returns
`String`

Throws
`JSONException`	if no such mapping exists.

has

Added in API level 1

public boolean has (String name)

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

Parameters
`name`	`String`

Returns
`boolean`

isNull

Added in API level 1

public boolean isNull (String name)

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

Parameters
`name`	`String`

Returns
`boolean`

keys

Added in API level 1

public Iterator<String> keys ()

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.

Returns
`Iterator<String>`

length

Added in API level 1

public int length ()

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

Returns
`int`

names

Added in API level 1

public JSONArray names ()

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

Returns
`JSONArray`

numberToString

Added in API level 1

public static String numberToString (Number number)

Encodes the number as a JSON string.

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

Returns
`String`

Throws
`JSONException`

opt

Added in API level 1

public Object opt (String name)

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

Parameters
`name`	`String`

Returns
`Object`

optBoolean

Added in API level 1

public 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, or fallback otherwise.

Parameters
`name`	`String`
`fallback`	`boolean`

Returns
`boolean`

optBoolean

Added in API level 1

public boolean optBoolean (String name)

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

Parameters
`name`	`String`

Returns
`boolean`

optDouble

Added in API level 1

public 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, or fallback otherwise.

Parameters
`name`	`String`
`fallback`	`double`

Returns
`double`

optDouble

Added in API level 1

public double optDouble (String name)

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

Parameters
`name`	`String`

Returns
`double`

optInt

Added in API level 1

public 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, or fallback otherwise.

Parameters
`name`	`String`
`fallback`	`int`

Returns
`int`

optInt

Added in API level 1

public int optInt (String name)

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

Parameters
`name`	`String`

Returns
`int`

optJSONArray

Added in API level 1

public JSONArray optJSONArray (String name)

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

Parameters
`name`	`String`

Returns
`JSONArray`

optJSONObject

Added in API level 1

public JSONObject optJSONObject (String name)

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

Parameters
`name`	`String`

Returns
`JSONObject`

optLong

Added in API level 1

public long optLong (String name)

Returns the value mapped by name if it exists and is a long or can be coerced to a long, or 0 otherwise. Note that JSON represents numbers as doubles, so this is lossy; use strings to transfer numbers via JSON.

Parameters
`name`	`String`

Returns
`long`

optLong

Added in API level 1

public 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, or fallback otherwise. Note that JSON represents numbers as doubles, so this is lossy; use strings to transfer numbers via JSON.

Parameters
`name`	`String`
`fallback`	`long`

Returns
`long`

optString

Added in API level 1

public String optString (String name, 
                String fallback)

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

Parameters
`name`	`String`
`fallback`	`String`

Returns
`String`

optString

Added in API level 1

public String optString (String name)

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

Parameters
`name`	`String`

Returns
`String`

put

Added in API level 1

public JSONObject put (String name, 
                double value)

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

Parameters
`name`	`String`
`value`	`double`: a finite value. May not be `NaNs` or `infinities`.

Returns
`JSONObject`	this object.

Throws
`JSONException`

put

Added in API level 1

public JSONObject put (String name, 
                boolean value)

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

Parameters
`name`	`String`
`value`	`boolean`

Returns
`JSONObject`	this object.

Throws
`JSONException`

put

Added in API level 1

public JSONObject put (String name, 
                int value)

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

Parameters
`name`	`String`
`value`	`int`

Returns
`JSONObject`	this object.

Throws
`JSONException`

put

Added in API level 1

public JSONObject put (String name, 
                long value)

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

Parameters
`name`	`String`
`value`	`long`

Returns
`JSONObject`	this object.

Throws
`JSONException`

put

Added in API level 1

public JSONObject put (String name, 
                Object value)

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

Returns
`JSONObject`	this object.

Throws
`JSONException`

putOpt

Added in API level 1

public JSONObject putOpt (String name, 
                Object value)

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

Parameters
`name`	`String`
`value`	`Object`

Returns
`JSONObject`

Throws
`JSONException`

quote

Added in API level 1

public static String quote (String data)

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

Parameters
`data`	`String`: the string to encode. Null will be interpreted as an empty string.

Returns
`String`

remove

Added in API level 1

public Object remove (String name)

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

Parameters
`name`	`String`

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

toJSONArray

Added in API level 1

public JSONArray toJSONArray (JSONArray names)

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.

Parameters
`names`	`JSONArray`

Returns
`JSONArray`

Throws
`JSONException`

toString

Added in API level 1

public String toString ()

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

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

Returns
`String`	a string representation of the object.

toString

Added in API level 1

public String toString (int indentSpaces)

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

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

Parameters
`indentSpaces`	`int`: the number of spaces to indent for each level of nesting.

Returns
`String`

Throws
`JSONException`

wrap

Added in API level 19

public static Object wrap (Object o)

Wraps the given object if necessary.

If the object is null or , returns NULL. If the object is a JSONArray or JSONObject, no wrapping is necessary. If the object is NULL, no wrapping is necessary. If the object is an array or Collection, returns an equivalent JSONArray. If the object is a Map, returns an equivalent JSONObject. If the object is a primitive wrapper type or String, returns the object. Otherwise if the object is from a java package, returns the result of toString. If wrapping fails, returns null.

Parameters
`o`	`Object`

Returns
`Object`