net.yura.mobile.io.json

Class JSONWriter

java.lang.Object

net.yura.mobile.io.json.JSONWriter

public class JSONWriter
extends java.lang.Object

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.

Version:

2

Author:

JSON.org

Field Summary

Fields

Modifier and Type	Field and Description
protected char	mode The current mode.
protected java.io.Writer	writer The writer that will receive the output.

Constructor Summary

Constructors

Constructor and Description
JSONWriter(java.io.Writer w) Make a fresh JSONWriter.

Method Summary

Modifier and Type	Method and Description
JSONWriter	array() Begin appending a new array.
JSONWriter	endArray() End an array.
JSONWriter	endObject() End an object.
JSONWriter	key(java.lang.String s) Append a key.
JSONWriter	nullValue() Append an object value.
JSONWriter	object() Begin appending a new object.
static java.lang.String	trimNumber(java.lang.String s)
JSONWriter	value(boolean b) Append either the value true or the value false.
JSONWriter	value(char string)
JSONWriter	value(double d) Append a double value.
JSONWriter	value(long l) Append a long value.
JSONWriter	value(java.lang.String string)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

mode

protected char mode

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

writer

protected java.io.Writer writer

The writer that will receive the output.

Constructor Detail

JSONWriter

public JSONWriter(java.io.Writer w)

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

Method Detail

array

public JSONWriter array()
                 throws java.io.IOException

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).

java.io.IOException

endArray

public JSONWriter endArray()
                    throws java.io.IOException

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

Returns:

this

Throws:

JSONException - If incorrectly nested.

java.io.IOException

endObject

public JSONWriter endObject()
                     throws java.io.IOException

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

Returns:

this

Throws:

JSONException - If incorrectly nested.

java.io.IOException

key

public JSONWriter key(java.lang.String s)
               throws java.io.IOException

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

Parameters:

s - 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.

java.io.IOException

object

public JSONWriter object()
                  throws java.io.IOException

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).

java.io.IOException

value

public JSONWriter value(boolean b)
                 throws java.io.IOException

Append either the value true or the value false.

Parameters:

b - A boolean.

Returns:

this

Throws:

JSONException

java.io.IOException

value

public JSONWriter value(double d)
                 throws java.io.IOException

Append a double value.

Parameters:

d - A double.

Returns:

this

Throws:

JSONException - If the number is not finite.

java.io.IOException

trimNumber

public static java.lang.String trimNumber(java.lang.String s)

value

public JSONWriter value(long l)
                 throws java.io.IOException

Append a long value.

Parameters:

l - A long.

Returns:

this

Throws:

JSONException

java.io.IOException

nullValue

public JSONWriter nullValue()
                     throws java.io.IOException

Append an object value.

Parameters:

o - The object to append. It can be null, or a Boolean, Number, String, JSONObject, or JSONArray, or an object with a toJSONString() method.

Returns:

this

Throws:

JSONException - If the value is out of sequence.

java.io.IOException

value

public JSONWriter value(char string)
                 throws java.io.IOException

Throws:

java.io.IOException

value

public JSONWriter value(java.lang.String string)
                 throws java.io.IOException

Throws:

java.io.IOException