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 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
.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 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.
|
JSONObject(java.lang.String baseName,
java.util.Locale locale)
Construct a JSONObject from a ResourceBundle.
|
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 |
keys()
Get an enumeration of the keys of the JSONObject.
|
java.util.Set |
keySet()
Get a set of 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 number)
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.
|
static java.io.Writer |
quote(java.lang.String string,
java.io.Writer w) |
java.lang.Object |
remove(java.lang.String key)
Remove a name and its value, if present.
|
static java.lang.Object |
stringToValue(java.lang.String string)
Try to convert a string into a number, boolean, or null.
|
static void |
testValidity(java.lang.Object o)
Throw an exception if the object is a NaN or infinite number.
|
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.
|
static java.lang.String |
valueToString(java.lang.Object value)
Make a JSON text of an Object value.
|
static java.lang.Object |
wrap(java.lang.Object object)
Wrap an object, if necessary.
|
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
- 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 map)
map
- A map object that can be used to initialize the contents of the JSONObject.JSONException
- if there is a problempublic 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(java.lang.String baseName, java.util.Locale locale) throws JSONException
baseName
- The ResourceBundle base name.locale
- The Locale to load the ResourceBundle for.JSONException
- If any JSONExceptions are detected.public JSONObject accumulate(java.lang.String key, java.lang.Object value) throws JSONException
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.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)
jo
- A JSONObjectpublic static java.lang.String[] getNames(java.lang.Object object)
object
- An Objectpublic java.lang.String getString(java.lang.String key) throws JSONException
key
- A key string.JSONException
- if there is no string value for the key.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 keys()
public java.util.Set keySet()
public int length()
public JSONArray names()
public static java.lang.String numberToString(java.lang.Number number) throws JSONException
number
- 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
- if there is a problempublic 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
- if there is a problempublic 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
- the key to usevalue
- the value to saveJSONException
- 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 static java.io.Writer quote(java.lang.String string, java.io.Writer w) throws java.io.IOException
java.io.IOException
public java.lang.Object remove(java.lang.String key)
key
- The name to be removed.public static java.lang.Object stringToValue(java.lang.String string)
string
- A String.public static void testValidity(java.lang.Object o) throws JSONException
o
- The object to test.JSONException
- If o is a non-finite number.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 static java.lang.String valueToString(java.lang.Object value) throws JSONException
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.public static java.lang.Object wrap(java.lang.Object object)
object
- The object to wrappublic java.io.Writer write(java.io.Writer writer) throws JSONException
Warning: This method assumes that the data structure is acyclical.
writer
- a WriterJSONException
- if there is a problem