org.apache.tapestry.json
Interface IJSONWriter

All Known Implementing Classes:

JSONWriterImpl

public interface IJSONWriter

JavaScript Object Notation writer interface that defines an object capable of writing JSON style output.

Author:

JSON.org, jkuhnert

See Also:

http://www.json.org/

Method Summary

IJSONWriter	accumulate(java.lang.String key, java.lang.Object value) Accumulate values under a key.
void	close() Causes any un-ended blocks to be closed, as well as any reasources associated with writer to be flushed/written.
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.
IJSONWriter	getJSONObject(java.lang.String key) Get the JSONObject value associated with a key.
JSONObject	getJSONSource() Allows access to the underlying JSONObject being used to write content.
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.
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.
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.
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.
IJSONWriter	optJSONObject(java.lang.String key) Get an optional JSONObject associated with a key.
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.
IJSONWriter	put(java.lang.String key, boolean value) Put a key/boolean pair in the JSONObject.
IJSONWriter	put(java.lang.String key, double value) Put a key/double pair in the JSONObject.
IJSONWriter	put(java.lang.String key, int value) Put a key/int pair in the JSONObject.
IJSONWriter	put(java.lang.String key, java.lang.Object value) Put a key/value pair in the JSONObject.
IJSONWriter	putOpt(java.lang.String key, java.lang.Object value) Put a key/value pair in the JSONObject, but only if the value is non-null.
java.lang.Object	remove(java.lang.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.
java.lang.String	toString() Make an JSON external form string of this JSONObject.
java.lang.String	toString(int indentFactor) Make a prettyprinted JSON external form string of this JSONObject.

Method Detail

accumulate

IJSONWriter accumulate(java.lang.String key,
                       java.lang.Object value)

Accumulate values under a key. It is similar to the put method except that if there is already an object stored under the key then a JSONArray is stored under the key to hold all of the accumulated values. If there is already a JSONArray, then the new value is appended to it. In contrast, the put method replaces the previous value.

Parameters:

key - A key string.

value - An object to be accumulated under the key.

Returns:

this.

Throws:

java.lang.NullPointerException - if the key is null

get

java.lang.Object get(java.lang.String key)

Get the value object associated with a key.

Parameters:

key - A key string.

Returns:

The object associated with the key.

Throws:

NoSuchElementException - if the key is not found.

getBoolean

boolean getBoolean(java.lang.String key)

Get the boolean value associated with a key.

Parameters:

key - A key string.

Returns:

The truth.

Throws:

NoSuchElementException - if the key is not found.

java.lang.ClassCastException - if the value is not a Boolean or the String "true" or "false".

getDouble

double getDouble(java.lang.String key)

Get the double value associated with a key.

Parameters:

key - A key string.

Returns:

The numeric value.

Throws:

java.lang.NumberFormatException - if the value cannot be converted to a number.

NoSuchElementException - if the key is not found or if the value is a Number object.

getInt

int getInt(java.lang.String key)

Get the int value associated with a key.

Parameters:

key - A key string.

Returns:

The integer value.

Throws:

NoSuchElementException - if the key is not found

java.lang.NumberFormatException - if the value cannot be converted to a number.

getJSONArray

JSONArray getJSONArray(java.lang.String key)

Get the JSONArray value associated with a key.

Parameters:

key - A key string.

Returns:

A JSONArray which is the value.

Throws:

NoSuchElementException - if the key is not found or if the value is not a JSONArray.

getJSONObject

IJSONWriter getJSONObject(java.lang.String key)

Get the JSONObject value associated with a key.

Parameters:

key - A key string.

Returns:

A JSONObject which is the value.

Throws:

NoSuchElementException - if the key is not found or if the value is not a JSONObject.

getString

java.lang.String getString(java.lang.String key)

Get the string associated with a key.

Parameters:

key - A key string.

Returns:

A string which is the value.

Throws:

NoSuchElementException - if the key is not found.

has

boolean has(java.lang.String key)

Determine if the JSONObject contains a specific key.

Parameters:

key - A key string.

Returns:

true if the key exists in the JSONObject.

isNull

boolean isNull(java.lang.String key)

Determine if the value associated with the key is null or if there is no value.

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.

keys

java.util.Iterator keys()

Get an enumeration of the keys of the JSONObject.

Returns:

An iterator of the keys.

length

int length()

Get the number of keys stored in the JSONObject.

Returns:

The number of keys in the JSONObject.

names

JSONArray names()

Produce a JSONArray containing the names of the elements of this JSONObject.

Returns:

A JSONArray containing the key strings, or null if the JSONObject is empty.

opt

java.lang.Object opt(java.lang.String key)

Get an optional value associated with a key.

Parameters:

key - A key string.

Returns:

An object which is the value, or null if there is no value.

Throws:

java.lang.NullPointerException - The key must not be null.

optBoolean

boolean optBoolean(java.lang.String key)

Get an optional boolean associated with a key. It returns false if there is no such key, or if the value is not Boolean.TRUE or the String "true".

Parameters:

key - A key string.

Returns:

The truth.

optBoolean

boolean optBoolean(java.lang.String key,
                   boolean defaultValue)

Get an optional boolean associated with a key. It returns the defaultValue if there is no such key, or if it is not a Boolean or the String "true" or "false" (case insensitive).

Parameters:

key - A key string.

defaultValue - The default.

Returns:

The truth.

optDouble

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. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters:

key - A string which is the key.

Returns:

An object which is the value.

optDouble

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. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters:

key - A key string.

defaultValue - The default.

Returns:

An object which is the value.

optInt

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. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters:

key - A key string.

Returns:

An object which is the value.

optInt

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. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters:

key - A key string.

defaultValue - The default.

Returns:

An object which is the value.

optJSONArray

JSONArray optJSONArray(java.lang.String key)

Get an optional JSONArray associated with a key. It returns null if there is no such key, or if its value is not a JSONArray.

Parameters:

key - A key string.

Returns:

A JSONArray which is the value.

optJSONObject

IJSONWriter optJSONObject(java.lang.String key)

Get an optional JSONObject associated with a key. It returns null if there is no such key, or if its value is not a JSONObject.

Parameters:

key - A key string.

Returns:

A JSONObject which is the value.

optString

java.lang.String optString(java.lang.String key)

Get an optional string associated with a key. It returns an empty string if there is no such key. If the value is not a string and is not null, then it is coverted to a string.

Parameters:

key - A key string.

Returns:

A string which is the value.

optString

java.lang.String optString(java.lang.String key,
                           java.lang.String defaultValue)

Get an optional string associated with a key. It returns the defaultValue if there is no such key.

Parameters:

key - A key string.

defaultValue - The default.

Returns:

A string which is the value.

put

IJSONWriter put(java.lang.String key,
                boolean value)

Put a key/boolean pair in the JSONObject.

Parameters:

key - A key string.

value - A boolean which is the value.

Returns:

this.

put

IJSONWriter put(java.lang.String key,
                double value)

Put a key/double pair in the JSONObject.

Parameters:

key - A key string.

value - A double which is the value.

Returns:

this.

put

IJSONWriter put(java.lang.String key,
                int value)

Put a key/int pair in the JSONObject.

Parameters:

key - A key string.

value - An int which is the value.

Returns:

this.

put

IJSONWriter put(java.lang.String key,
                java.lang.Object value)

Put a key/value pair in the JSONObject. If the value is null, then the key will be removed from the JSONObject if it is present.

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, String, or the JSONObject.NULL object.

Returns:

this.

Throws:

java.lang.NullPointerException - The key must be non-null.

putOpt

IJSONWriter putOpt(java.lang.String key,
                   java.lang.Object value)

Put a key/value pair in the JSONObject, but only if the value is non-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, String, or the JSONObject.NULL object.

Returns:

this.

Throws:

java.lang.NullPointerException - The key must be non-null.

remove

java.lang.Object remove(java.lang.String key)

Remove a name and its value, if present.

Parameters:

key - The name to be removed.

Returns:

The value that was associated with the name, or null if there was no value.

toJSONArray

JSONArray toJSONArray(JSONArray names)

Produce a JSONArray containing the values of the members of this JSONObject.

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.

toString

java.lang.String toString()

Make an JSON external form string of this JSONObject. For compactness, no unnecessary whitespace is added.

Warning: This method assumes that the data structure is acyclical.

Overrides:

toString in class java.lang.Object

Returns:

a printable, displayable, portable, transmittable representation of the object, beginning with { (left brace) and ending with } (right brace).

toString

java.lang.String toString(int indentFactor)

Make a prettyprinted JSON external form string of this JSONObject.

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).

close

void close()

Causes any un-ended blocks to be closed, as well as any reasources associated with writer to be flushed/written.

getJSONSource

JSONObject getJSONSource()

Allows access to the underlying JSONObject being used to write content.

Returns:

The JSONObject being delegated to.