public class

JSONWriter

extends Object
java.lang.Object
   ↳ org.json.JSONWriter
Known Direct Subclasses

Class Overview

JSONWriter provides a quick and convenient way of producing JSON text. The texts produced strictly conform to JSON syntax rules. No whitespace is added, so the results are ready for transmission or storage. Each instance of JSONWriter can produce one JSON text.

A JSONWriter instance provides a value method for appending values to the text, and a key method for adding keys before values in objects. There are array and endArray methods that make and bound array values, and object and endObject methods which make and bound object values. All of these methods return the JSONWriter instance, permitting a cascade style. For example, 

 new JSONWriter(myWriter)
     .object()
         .key("JSON")
         .value("Hello, World!")
     .endObject();
which writes 
 {"JSON":"Hello, World!"}

The first method called must be array or object. There are no methods for adding commas or colons. JSONWriter adds them for you. Objects and arrays can be nested up to 20 levels deep.

This can sometimes be easier than using a JSONObject to build a string.

Summary

Fields
protected char mode The current mode.
protected Writer writer The writer that will receive the output.
Public Constructors
JSONWriter(Writer w)
Make a fresh JSONWriter.
Public Methods
JSONWriter array()
Begin appending a new array.
JSONWriter endArray()
End an array.
JSONWriter endObject()
End an object.
JSONWriter key(String string)
Append a key.
JSONWriter object()
Begin appending a new object.
JSONWriter value(double d)
Append a double value.
JSONWriter value(long l)
Append a long value.
JSONWriter value(boolean b)
Append either the value true or the value false.
JSONWriter value(Object object)
Append an object value.
[Expand]
Inherited Methods
From class java.lang.Object

Fields

protected char mode

The current mode. Values: 'a' (array), 'd' (done), 'i' (initial), 'k' (key), 'o' (object).

protected Writer writer

The writer that will receive the output.

Public Constructors

public JSONWriter (Writer w)

Make a fresh JSONWriter. It can be used to build one JSON text.

Public Methods

public JSONWriter array ()

Begin appending a new array. All values until the balancing endArray will be appended to this array. The endArray method must be called to mark the array's end.

Returns
  • this
Throws
JSONException If the nesting is too deep, or if the object is started in the wrong place (for example as a key or after the end of the outermost array or object).

public JSONWriter endArray ()

End an array. This method most be called to balance calls to array.

Returns
  • this
Throws
JSONException If incorrectly nested.

public JSONWriter endObject ()

End an object. This method most be called to balance calls to object.

Returns
  • this
Throws
JSONException If incorrectly nested.

public JSONWriter key (String string)

Append a key. The key will be associated with the next value. In an object, every value must be preceded by a key.

Parameters
string A key string.
Returns
  • this
Throws
JSONException If the key is out of place. For example, keys do not belong in arrays or if the key is null.

public JSONWriter object ()

Begin appending a new object. All keys and values until the balancing endObject will be appended to this object. The endObject method must be called to mark the object's end.

Returns
  • this
Throws
JSONException If the nesting is too deep, or if the object is started in the wrong place (for example as a key or after the end of the outermost array or object).

public JSONWriter value (double d)

Append a double value.

Parameters
d A double.
Returns
  • this
Throws
JSONException If the number is not finite.

public JSONWriter value (long l)

Append a long value.

Parameters
l A long.
Returns
  • this
Throws
JSONException

public JSONWriter value (boolean b)

Append either the value true or the value false.

Parameters
b A boolean.
Returns
  • this
Throws
JSONException

public JSONWriter value (Object object)

Append an object value.

Parameters
object The object to append. It can be null, or a Boolean, Number, String, JSONObject, or JSONArray, or an object that implements JSONString.
Returns
  • this
Throws
JSONException If the value is out of sequence.