org.json
public class JSONObject extends Object
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
coersion for you.
The put
methods adds values to 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 sysntax 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).0-
(octal) or
0x-
(hex) prefix.Field Summary | |
---|---|
static Object | NULL
It is sometimes more convenient and less ambiguous to have a
NULL object than to use Java's null value.
|
Constructor Summary | |
---|---|
JSONObject()
Construct an empty JSONObject. | |
JSONObject(JSONObject jo, String[] sa)
Construct a JSONObject from a subset of another JSONObject.
| |
JSONObject(JSONTokener x)
Construct a JSONObject from a JSONTokener. | |
JSONObject(Map map)
Construct a JSONObject from a Map. | |
JSONObject(Object object, String[] names)
Construct a JSONObject from an Object, using reflection to find the
public members. | |
JSONObject(String string)
Construct a JSONObject from a string.
|
Method Summary | |
---|---|
JSONObject | accumulate(String key, Object value)
Accumulate values under a key. |
JSONObject | append(String key, Object value)
Append values to the array under a key. |
static String | doubleToString(double d)
Produce a string from a double. |
Object | get(String key)
Get the value object associated with a key.
|
boolean | getBoolean(String key)
Get the boolean value associated with a key.
|
double | getDouble(String key)
Get the double value associated with a key. |
int | getInt(String key)
Get the int value associated with a key. |
JSONArray | getJSONArray(String key)
Get the JSONArray value associated with a key.
|
JSONObject | getJSONObject(String key)
Get the JSONObject value associated with a key.
|
long | getLong(String key)
Get the long value associated with a key. |
String | getString(String key)
Get the string associated with a key.
|
boolean | has(String key)
Determine if the JSONObject contains a specific key. |
boolean | isNull(String key)
Determine if the value associated with the key is null or if there is
no value. |
Iterator | keys()
Get an enumeration of the keys of the JSONObject.
|
int | length()
Get the number of keys stored in the JSONObject.
|
JSONArray | names()
Produce a JSONArray containing the names of the elements of this
JSONObject. |
static String | numberToString(Number n)
Produce a string from a Number. |
Object | opt(String key)
Get an optional value associated with a key. |
boolean | optBoolean(String key)
Get an optional boolean associated with a key.
|
boolean | optBoolean(String key, boolean defaultValue)
Get an optional boolean associated with a key.
|
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.
|
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.
|
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.
|
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.
|
JSONArray | optJSONArray(String key)
Get an optional JSONArray associated with a key.
|
JSONObject | optJSONObject(String key)
Get an optional JSONObject associated with a key.
|
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.
|
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.
|
String | optString(String key)
Get an optional string associated with a key.
|
String | optString(String key, String defaultValue)
Get an optional string associated with a key.
|
JSONObject | put(String key, Collection value)
Put a key/value pair in the JSONObject, where the value will be a
JSONArray which is produced from a Collection. |
JSONObject | put(String key, boolean value)
Put a key/boolean pair in the JSONObject.
|
JSONObject | put(String key, double value)
Put a key/double pair in the JSONObject.
|
JSONObject | put(String key, int value)
Put a key/int pair in the JSONObject.
|
JSONObject | put(String key, long value)
Put a key/long pair in the JSONObject.
|
JSONObject | put(String key, Map value)
Put a key/value pair in the JSONObject, where the value will be a
JSONObject which is produced from a Map. |
JSONObject | put(String key, Object value)
Put a key/value pair in the JSONObject. |
JSONObject | putOpt(String key, Object value)
Put a key/value pair in the JSONObject, but only if the
key and the value are both non-null. |
static String | quote(String string)
Produce a string in double quotes with backslash sequences in all the
right places. |
Object | remove(String key)
Remove a name and its value, if present. |
JSONArray | toJSONArray(JSONArray names)
Produce a JSONArray containing the values of the members of this
JSONObject. |
String | toString()
Make a JSON text of this JSONObject. |
String | toString(int indentFactor)
Make a prettyprinted JSON text of this JSONObject.
|
Writer | write(Writer writer)
Write the contents of the JSONObject as JSON text to a writer.
|
NULL
object than to use Java's null
value.
JSONObject.NULL.equals(null)
returns true
.
JSONObject.NULL.toString()
returns "null"
.Parameters: jo A JSONObject. sa An array of strings.
Throws: JSONException If a value is a non-finite number.
Parameters: x A JSONTokener object containing the source string.
Throws: JSONException If there is a syntax error in the source string.
Parameters: map A map object that can be used to initialize the contents of the 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 used from the object.
Parameters: string A string beginning
with {
(left brace) and ending
with }
(right brace).
Throws: JSONException If there is a syntax error in the source string.
Parameters: key A key string. value An object to be accumulated under the key.
Returns: this.
Throws: JSONException If the value is an invalid number or if the key is null.
Parameters: key A key string. value An object to be accumulated under the key.
Returns: this.
Throws: JSONException If the key is null or if the current value associated with the key is not a JSONArray.
Parameters: d A double.
Returns: A String.
Parameters: key A key string.
Returns: The object associated with the key.
Throws: JSONException if the key is not found.
Parameters: key A key string.
Returns: The truth.
Throws: JSONException if the value is not a Boolean or the String "true" or "false".
Parameters: key A key string.
Returns: The numeric value.
Throws: JSONException if the key is not found or if the value is not a Number object and cannot be converted to a number.
Parameters: key A key string.
Returns: The integer value.
Throws: JSONException if the key is not found or if the value cannot be converted to an integer.
Parameters: key A key string.
Returns: A JSONArray which is the value.
Throws: JSONException if the key is not found or if the value is not a JSONArray.
Parameters: key A key string.
Returns: A JSONObject which is the value.
Throws: JSONException if the key is not found or if the value is not a JSONObject.
Parameters: key A key string.
Returns: The long value.
Throws: JSONException if the key is not found or if the value cannot be converted to a long.
Parameters: key A key string.
Returns: A string which is the value.
Throws: JSONException if the key is not found.
Parameters: key A key string.
Returns: true if the key exists in the JSONObject.
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.
Returns: An iterator of the keys.
Returns: The number of keys in the JSONObject.
Returns: A JSONArray containing the key strings, or null if the JSONObject is empty.
Parameters: n A Number
Returns: A String.
Throws: JSONException If n is a non-finite number.
Parameters: key A key string.
Returns: An object which is the value, or null if there is no value.
Parameters: key A key string.
Returns: The truth.
Parameters: key A key string. defaultValue The default.
Returns: The truth.
Parameters: key A string which is the key.
Returns: An object which is the value.
Parameters: key A key string. defaultValue The default.
Returns: An object which is the value.
Parameters: key A key string.
Returns: An object which is the value.
Parameters: key A key string. defaultValue The default.
Returns: An object which is the value.
Parameters: key A key string.
Returns: A JSONArray which is the value.
Parameters: key A key string.
Returns: A JSONObject which is the value.
Parameters: key A key string.
Returns: An object which is the value.
Parameters: key A key string. defaultValue The default.
Returns: An object which is the value.
Parameters: key A key string.
Returns: A string which is the value.
Parameters: key A key string. defaultValue The default.
Returns: A string which is the value.
Parameters: key A key string. value A Collection value.
Returns: this.
Throws: JSONException
Parameters: key A key string. value A boolean which is the value.
Returns: this.
Throws: JSONException If the key is null.
Parameters: key A key string. value A double which is the value.
Returns: this.
Throws: JSONException If the key is null or if the number is invalid.
Parameters: key A key string. value An int which is the value.
Returns: this.
Throws: JSONException If the key is null.
Parameters: key A key string. value A long which is the value.
Returns: this.
Throws: JSONException If the key is null.
Parameters: key A key string. value A Map value.
Returns: this.
Throws: JSONException
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.
Throws: JSONException If the value is non-finite number or if the key is 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.
Throws: JSONException If the value is a non-finite number.
Parameters: string A String
Returns: A String correctly formatted for insertion in a JSON text.
Parameters: key The name to be removed.
Returns: The value that was associated with the name, or null if there was no value.
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.
Throws: JSONException If any of the values are non-finite numbers.
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).
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).
Throws: JSONException If the object contains an invalid number.
Warning: This method assumes that the data structure is acyclical.
Returns: The writer.
Throws: JSONException