java.lang.Object | |
↳ | org.json.JSONObject |
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:
,
(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
.=
or =>
as well as
by :
.;
(semicolon) as
well as by ,
(comma).0x-
(hex) prefix.Fields | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
NULL | It is sometimes more convenient and less ambiguous to have a
NULL object than to use Java's null value. |
Public Constructors | |||||||||||
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Construct an empty JSONObject.
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Construct a JSONObject from a subset of another JSONObject.
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Construct a JSONObject from a JSONTokener.
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Construct a JSONObject from a Map.
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Construct a JSONObject from an Object using bean getters.
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Construct a JSONObject from an Object, using reflection to find the
public members.
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Construct a JSONObject from a source JSON text string.
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Construct a JSONObject from a ResourceBundle.
|
Public Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Accumulate values under a key.
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Append values to the array under a key.
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Produce a string from a double.
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Get the value object associated with a key.
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Get the boolean value associated with a key.
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Get the double value associated with a key.
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Get the int value associated with a key.
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Get the JSONArray value associated with a key.
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Get the JSONObject value associated with a key.
| |||||||||||
Get the long value associated with a key.
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Get an array of field names from a JSONObject.
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Get an array of field names from an Object.
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Get the string associated with a key.
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Determine if the JSONObject contains a specific key.
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Increment a property of a JSONObject.
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Determine if the value associated with the key is null or if there is
no value.
| |||||||||||
Get an enumeration of the keys of the JSONObject.
| |||||||||||
Get the number of keys stored in the JSONObject.
| |||||||||||
Produce a JSONArray containing the names of the elements of this
JSONObject.
| |||||||||||
Produce a string from a Number.
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Get an optional value associated with a key.
| |||||||||||
Get an optional boolean associated with a key.
| |||||||||||
Get an optional boolean associated with a 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.
| |||||||||||
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.
| |||||||||||
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.
| |||||||||||
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.
| |||||||||||
Get an optional JSONArray associated with a key.
| |||||||||||
Get an optional JSONObject associated with a key.
| |||||||||||
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.
| |||||||||||
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.
| |||||||||||
Get an optional string associated with a key.
| |||||||||||
Get an optional string associated with a key.
| |||||||||||
Put a key/value pair in the JSONObject.
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Put a key/value pair in the JSONObject, where the value will be a
JSONArray which is produced from a Collection.
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Put a key/double pair in the JSONObject.
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Put a key/value pair in the JSONObject, where the value will be a
JSONObject which is produced from a Map.
| |||||||||||
Put a key/int pair in the JSONObject.
| |||||||||||
Put a key/long pair in the JSONObject.
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Put a key/boolean pair in the JSONObject.
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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.
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Put a key/value pair in the JSONObject, but only if the
key and the value are both non-null.
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Produce a string in double quotes with backslash sequences in all the
right places.
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Remove a name and its value, if present.
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Try to convert a string into a number, boolean, or null.
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Throw an exception if the object is a NaN or infinite number.
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Produce a JSONArray containing the values of the members of this
JSONObject.
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Make a prettyprinted JSON text of this JSONObject.
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Make a JSON text of this JSONObject.
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Make a JSON text of an Object value.
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Wrap an object, if necessary.
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Write the contents of the JSONObject as JSON text to a writer.
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[Expand]
Inherited Methods | |||||||||||
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From class
java.lang.Object
|
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"
.
Construct an empty JSONObject.
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.
jo | A JSONObject. |
---|---|
names | An array of strings. |
JSONException | |
---|---|
JSONException | If a value is a non-finite number or if a name is duplicated. |
Construct a JSONObject from a JSONTokener.
x | A JSONTokener object containing the source string. |
---|
JSONException | If there is a syntax error in the source string or a duplicated key. |
---|
Construct a JSONObject from a Map.
map | A map object that can be used to initialize the contents of the JSONObject. |
---|
JSONException |
---|
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"
.
bean | An object that has getter methods that should be used to make a JSONObject. |
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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.
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. |
Construct a JSONObject from a source JSON text string. This is the most commonly used JSONObject constructor.
source | A string beginning
with { (left brace) and ending
with } (right brace). |
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JSONException | If there is a syntax error in the source string or a duplicated key. |
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Construct a JSONObject from a ResourceBundle.
baseName | The ResourceBundle base name. |
---|---|
locale | The Locale to load the ResourceBundle for. |
JSONException | If any JSONExceptions are detected. |
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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.
key | A key string. |
---|---|
value | An object to be accumulated under the key. |
JSONException | If the value is an invalid number or if the key is null. |
---|
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.
key | A key string. |
---|---|
value | An object to be accumulated under the key. |
JSONException | If the key is null or if the current value associated with the key is not a JSONArray. |
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Produce a string from a double. The string "null" will be returned if the number is not finite.
d | A double. |
---|
Get the value object associated with a key.
key | A key string. |
---|
JSONException | if the key is not found. |
---|
Get the boolean value associated with a key.
key | A key string. |
---|
JSONException | if the value is not a Boolean or the String "true" or "false". |
---|
Get the double value associated with a key.
key | A key string. |
---|
JSONException | if the key is not found or if the value is not a Number object and cannot be converted to a number. |
---|
Get the int value associated with a key.
key | A key string. |
---|
JSONException | if the key is not found or if the value cannot be converted to an integer. |
---|
Get the JSONArray value associated with a key.
key | A key string. |
---|
JSONException | if the key is not found or if the value is not a JSONArray. |
---|
Get the JSONObject value associated with a key.
key | A key string. |
---|
JSONException | if the key is not found or if the value is not a JSONObject. |
---|
Get the long value associated with a key.
key | A key string. |
---|
JSONException | if the key is not found or if the value cannot be converted to a long. |
---|
Get an array of field names from a JSONObject.
Get an array of field names from an Object.
Get the string associated with a key.
key | A key string. |
---|
JSONException | if the key is not found. |
---|
Determine if the JSONObject contains a specific key.
key | A key string. |
---|
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.
key | A key string. |
---|
JSONException | If there is already a property with this name that is not an Integer, Long, Double, or Float. |
---|
Determine if the value associated with the key is null or if there is no value.
key | A key string. |
---|
Get an enumeration of the keys of the JSONObject.
Get the number of keys stored in the JSONObject.
Produce a JSONArray containing the names of the elements of this JSONObject.
Produce a string from a Number.
number | A Number |
---|
JSONException | If n is a non-finite number. |
---|
Get an optional value associated with a key.
key | A key string. |
---|
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".
key | A key string. |
---|
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).
key | A key string. |
---|---|
defaultValue | The default. |
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.
key | A string which is the key. |
---|
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.
key | A key string. |
---|---|
defaultValue | The default. |
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.
key | A key string. |
---|
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.
key | A key string. |
---|---|
defaultValue | The default. |
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.
key | A key string. |
---|
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.
key | A key string. |
---|
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.
key | A key string. |
---|---|
defaultValue | The default. |
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.
key | A key string. |
---|
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.
key | A key string. |
---|
Get an optional string associated with a key. It returns the defaultValue if there is no such key.
key | A key string. |
---|---|
defaultValue | The default. |
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.
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. |
JSONException | If the value is non-finite number or if the key is null. |
---|
Put a key/value pair in the JSONObject, where the value will be a JSONArray which is produced from a Collection.
key | A key string. |
---|---|
value | A Collection value. |
JSONException |
---|
Put a key/double pair in the JSONObject.
key | A key string. |
---|---|
value | A double which is the value. |
JSONException | If the key is null or if the number is invalid. |
---|
Put a key/value pair in the JSONObject, where the value will be a JSONObject which is produced from a Map.
key | A key string. |
---|---|
value | A Map value. |
JSONException |
---|
Put a key/int pair in the JSONObject.
key | A key string. |
---|---|
value | An int which is the value. |
JSONException | If the key is null. |
---|
Put a key/long pair in the JSONObject.
key | A key string. |
---|---|
value | A long which is the value. |
JSONException | If the key is null. |
---|
Put a key/boolean pair in the JSONObject.
key | A key string. |
---|---|
value | A boolean which is the value. |
JSONException | If the key is null. |
---|
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.
JSONException | if the key is a duplicate |
---|
Put a key/value pair in the JSONObject, but only if the key and the value are both non-null.
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. |
JSONException | If the value is a non-finite number. |
---|
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.
string | A String |
---|
Remove a name and its value, if present.
key | The name to be removed. |
---|
Try to convert a string into a number, boolean, or null. If the string can't be converted, return the string.
string | A String. |
---|
Throw an exception if the object is a NaN or infinite number.
o | The object to test. |
---|
JSONException | If o is a non-finite number. |
---|
Produce a JSONArray containing the values of the members of this JSONObject.
names | A JSONArray containing a list of key strings. This determines the sequence of the values in the result. |
---|
JSONException | If any of the values are non-finite numbers. |
---|
Make a prettyprinted JSON text of this JSONObject.
Warning: This method assumes that the data structure is acyclical.
indentFactor | The number of spaces to add to each level of indentation. |
---|
{
(left brace) and ending
with }
(right brace).JSONException | If the object contains an invalid number. |
---|
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.
{
(left brace) and ending
with }
(right brace).
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.
value | The value to be serialized. |
---|
{
(left brace) and ending
with }
(right brace).JSONException | If the value is or contains an invalid number. |
---|
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.
object | The object to wrap |
---|
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.
JSONException |
---|