public class JSONObject
extends java.lang.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 coercion 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 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.
Modifier and Type | Field and Description |
---|---|
static java.lang.Object |
NULL
It is sometimes more convenient and less ambiguous to have a
NULL object than to
use Java's null value. |
Constructor and Description |
---|
JSONObject()
Construct an empty JSONObject.
|
JSONObject(JSONObject jo,
java.lang.String[] names)
Construct a JSONObject from a subset of another JSONObject.
|
JSONObject(JSONTokener x)
Construct a JSONObject from a JSONTokener.
|
JSONObject(java.util.Map<java.lang.Object,java.lang.Object> map)
Construct a JSONObject from a Map.
|
JSONObject(java.lang.Object bean)
Construct a JSONObject from an Object using bean getters.
|
JSONObject(java.lang.Object object,
java.lang.String[] names)
Construct a JSONObject from an Object, using reflection to find the public members.
|
JSONObject(java.lang.String source)
Construct a JSONObject from a source JSON text string.
|
Modifier and Type | Method and Description |
---|---|
JSONObject |
accumulate(java.lang.String key,
java.lang.Object value)
Accumulate values under a key.
|
JSONObject |
append(java.lang.String key,
java.lang.Object value)
Append values to the array under a key.
|
static java.lang.String |
doubleToString(double d)
Produce a string from a double.
|
java.lang.Object |
get(java.lang.String key)
Get the value object associated with a key.
|
boolean |
getBoolean(java.lang.String key)
Get the boolean value associated with a key.
|
double |
getDouble(java.lang.String key)
Get the double value associated with a key.
|
int |
getInt(java.lang.String key)
Get the int value associated with a key.
|
JSONArray |
getJSONArray(java.lang.String key)
Get the JSONArray value associated with a key.
|
JSONObject |
getJSONObject(java.lang.String key)
Get the JSONObject value associated with a key.
|
long |
getLong(java.lang.String key)
Get the long value associated with a key.
|
static java.lang.String[] |
getNames(JSONObject jo)
Get an array of field names from a JSONObject.
|
static java.lang.String[] |
getNames(java.lang.Object object)
Get an array of field names from an Object.
|
java.lang.String |
getString(java.lang.String key)
Get the string associated with a key.
|
boolean |
has(java.lang.String key)
Determine if the JSONObject contains a specific key.
|
JSONObject |
increment(java.lang.String key)
Increment a property of a JSONObject.
|
boolean |
isNull(java.lang.String key)
Determine if the value associated with the key is null or if there is no value.
|
java.util.Iterator<java.lang.Object> |
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 java.lang.String |
numberToString(java.lang.Number n)
Produce a string from a Number.
|
java.lang.Object |
opt(java.lang.String key)
Get an optional value associated with a key.
|
boolean |
optBoolean(java.lang.String key)
Get an optional boolean associated with a key.
|
boolean |
optBoolean(java.lang.String key,
boolean defaultValue)
Get an optional boolean associated with a key.
|
double |
optDouble(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.String key)
Get an optional JSONArray associated with a key.
|
JSONObject |
optJSONObject(java.lang.String key)
Get an optional JSONObject associated with a key.
|
long |
optLong(java.lang.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(java.lang.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.
|
java.lang.String |
optString(java.lang.String key)
Get an optional string associated with a key.
|
java.lang.String |
optString(java.lang.String key,
java.lang.String defaultValue)
Get an optional string associated with a key.
|
JSONObject |
put(java.lang.String key,
boolean value)
Put a key/boolean pair in the JSONObject.
|
JSONObject |
put(java.lang.String key,
java.util.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(java.lang.String key,
double value)
Put a key/double pair in the JSONObject.
|
JSONObject |
put(java.lang.String key,
int value)
Put a key/int pair in the JSONObject.
|
JSONObject |
put(java.lang.String key,
long value)
Put a key/long pair in the JSONObject.
|
JSONObject |
put(java.lang.String key,
java.util.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(java.lang.String key,
java.lang.Object value)
Put a key/value pair in the JSONObject.
|
JSONObject |
putOnce(java.lang.String key,
java.lang.Object value)
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.
|
JSONObject |
putOpt(java.lang.String key,
java.lang.Object value)
Put a key/value pair in the JSONObject, but only if the key and the value are both non-null.
|
static java.lang.String |
quote(java.lang.String string)
Produce a string in double quotes with backslash sequences in all the right places.
|
java.lang.Object |
remove(java.lang.String key)
Remove a name and its value, if present.
|
java.util.Iterator<java.lang.Object> |
sortedKeys()
Get an enumeration of the keys of the JSONObject.
|
static java.lang.Object |
stringToValue(java.lang.String s)
Try to convert a string into a number, boolean, or null.
|
JSONArray |
toJSONArray(JSONArray names)
Produce a JSONArray containing the values of the members of this JSONObject.
|
java.lang.String |
toString()
Make a JSON text of this JSONObject.
|
java.lang.String |
toString(int indentFactor)
Make a prettyprinted JSON text of this JSONObject.
|
java.io.Writer |
write(java.io.Writer writer)
Write the contents of the JSONObject as JSON text to a writer.
|
public static final java.lang.Object NULL
NULL
object than to
use Java's null
value. JSONObject.NULL.equals(null)
returns
true
. JSONObject.NULL.toString()
returns "null"
.public JSONObject()
public JSONObject(JSONObject jo, java.lang.String[] names)
jo
- A JSONObject.names
- An array of strings.JSONException
JSONException
- If a value is a non-finite number or if a name is duplicated.public JSONObject(JSONTokener x) throws JSONException
x
- A JSONTokener object containing the source string.JSONException
- If there is a syntax error in the source string or a duplicated key.public JSONObject(java.util.Map<java.lang.Object,java.lang.Object> map)
map
- A map object that can be used to initialize the contents of the JSONObject.JSONException
public JSONObject(java.lang.Object bean)
"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.public JSONObject(java.lang.Object object, java.lang.String[] names)
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.public JSONObject(java.lang.String source) throws JSONException
source
- A string beginning with {
(left brace) and
ending with }
(right brace).JSONException
- If there is a syntax error in the source string or a duplicated key.public JSONObject accumulate(java.lang.String key, java.lang.Object value) throws JSONException
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.public JSONObject append(java.lang.String key, java.lang.Object value) throws JSONException
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.public static java.lang.String doubleToString(double d)
d
- A double.public java.lang.Object get(java.lang.String key) throws JSONException
key
- A key string.JSONException
- if the key is not found.public boolean getBoolean(java.lang.String key) throws JSONException
key
- A key string.JSONException
- if the value is not a Boolean or the String "true" or "false".public double getDouble(java.lang.String key) throws JSONException
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.public int getInt(java.lang.String key) throws JSONException
key
- A key string.JSONException
- if the key is not found or if the value cannot be converted to an
integer.public JSONArray getJSONArray(java.lang.String key) throws JSONException
key
- A key string.JSONException
- if the key is not found or if the value is not a JSONArray.public JSONObject getJSONObject(java.lang.String key) throws JSONException
key
- A key string.JSONException
- if the key is not found or if the value is not a JSONObject.public long getLong(java.lang.String key) throws JSONException
key
- A key string.JSONException
- if the key is not found or if the value cannot be converted to a long.public static java.lang.String[] getNames(JSONObject jo)
public static java.lang.String[] getNames(java.lang.Object object)
public java.lang.String getString(java.lang.String key) throws JSONException
key
- A key string.JSONException
- if the key is not found.public boolean has(java.lang.String key)
key
- A key string.public JSONObject increment(java.lang.String key) throws JSONException
key
- A key string.JSONException
- If there is already a property with this name that is not an Integer,
Long, Double, or Float.public boolean isNull(java.lang.String key)
key
- A key string.public java.util.Iterator<java.lang.Object> keys()
public int length()
public JSONArray names()
public static java.lang.String numberToString(java.lang.Number n) throws JSONException
n
- A NumberJSONException
- If n is a non-finite number.public java.lang.Object opt(java.lang.String key)
key
- A key string.public boolean optBoolean(java.lang.String key)
key
- A key string.public boolean optBoolean(java.lang.String key, boolean defaultValue)
key
- A key string.defaultValue
- The default.public double optDouble(java.lang.String key)
key
- A string which is the key.public double optDouble(java.lang.String key, double defaultValue)
key
- A key string.defaultValue
- The default.public int optInt(java.lang.String key)
key
- A key string.public int optInt(java.lang.String key, int defaultValue)
key
- A key string.defaultValue
- The default.public JSONArray optJSONArray(java.lang.String key)
key
- A key string.public JSONObject optJSONObject(java.lang.String key)
key
- A key string.public long optLong(java.lang.String key)
key
- A key string.public long optLong(java.lang.String key, long defaultValue)
key
- A key string.defaultValue
- The default.public java.lang.String optString(java.lang.String key)
key
- A key string.public java.lang.String optString(java.lang.String key, java.lang.String defaultValue)
key
- A key string.defaultValue
- The default.public JSONObject put(java.lang.String key, boolean value) throws JSONException
key
- A key string.value
- A boolean which is the value.JSONException
- If the key is null.public JSONObject put(java.lang.String key, java.util.Collection<?> value) throws JSONException
key
- A key string.value
- A Collection value.JSONException
public JSONObject put(java.lang.String key, double value) throws JSONException
key
- A key string.value
- A double which is the value.JSONException
- If the key is null or if the number is invalid.public JSONObject put(java.lang.String key, int value) throws JSONException
key
- A key string.value
- An int which is the value.JSONException
- If the key is null.public JSONObject put(java.lang.String key, long value) throws JSONException
key
- A key string.value
- A long which is the value.JSONException
- If the key is null.public JSONObject put(java.lang.String key, java.util.Map<?,?> value) throws JSONException
key
- A key string.value
- A Map value.JSONException
public JSONObject put(java.lang.String key, java.lang.Object value) throws JSONException
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.public JSONObject putOnce(java.lang.String key, java.lang.Object value) throws JSONException
key
- value
- JSONException
- if the key is a duplicatepublic JSONObject putOpt(java.lang.String key, java.lang.Object value) throws JSONException
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.public static java.lang.String quote(java.lang.String string)
string
- A Stringpublic java.lang.Object remove(java.lang.String key)
key
- The name to be removed.public java.util.Iterator<java.lang.Object> sortedKeys()
public static java.lang.Object stringToValue(java.lang.String s)
s
- A String.public JSONArray toJSONArray(JSONArray names) throws JSONException
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.public java.lang.String toString()
Warning: This method assumes that the data structure is acyclical.
toString
in class java.lang.Object
{
(left brace) and ending with }
(right brace).public java.lang.String toString(int indentFactor) throws JSONException
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.public java.io.Writer write(java.io.Writer writer) throws JSONException
Warning: This method assumes that the data structure is acyclical.
JSONException