net.sf.json.util
Class JSONUtils

java.lang.Object
  net.sf.json.util.JSONUtils

public final class JSONUtils
extends Object

Provides useful methods on java objects and JSON values.

Version:

7

Author:

Andres Almiray

Field Summary

static String	DOUBLE_QUOTE Constant for char "
static String	SINGLE_QUOTE Constant for char '

Method Summary

static String	convertToJavaIdentifier(String key) Transforms the string into a valid Java Identifier. The default strategy is JavaIdentifierTransformer.NOOP
static String	convertToJavaIdentifier(String key, JsonConfig jsonConfig) Transforms the string into a valid Java Identifier. The default strategy is JavaIdentifierTransformer.NOOP
static String	doubleToString(double d) Produce a string from a double.
static String	getFunctionBody(String function) Returns the body of a function literal.
static String	getFunctionParams(String function) Returns the params of a function literal.
static Class	getInnerComponentType(Class type) Returns the inner-most component type of an Array.
static MorpherRegistry	getMorpherRegistry() Returns the singleton MorpherRegistry.
static Map	getProperties(JSONObject jsonObject) Creates a Map with all the properties of the JSONObject.
static Class	getTypeClass(Object obj) Returns the JSON type. Values are Object, String, Boolean, Number(subclasses) & JSONFunction.
static int	hashCode(Object value) Returns the hashcode of value. If null it will return JSONNull.getInstance().hashCode(). If value is JSON, JSONFunction or String, value.hashCode is returned, otherwise the value is transformed to a String an its hashcode is returned.
static boolean	hasQuotes(String input) Returns true if the input has single-quotes or double-quotes at both sides.
static boolean	isArray(Class clazz) Tests if a Class represents an array or Collection.
static boolean	isArray(Object obj) Tests if obj is an array or Collection.
static boolean	isBoolean(Class clazz) Tests if Class represents a Boolean or primitive boolean
static boolean	isBoolean(Object obj) Tests if obj is a Boolean or primitive boolean
static boolean	isDouble(Class clazz) Tests if Class represents a primitive double or wrapper.
static boolean	isFunction(Object obj) Tests if obj is javaScript function. Obj must be a non-null String and match "^function[ ]?\\(.\*\)[ ]?\\{.\*\}$"
static boolean	isFunctionHeader(Object obj) Tests if obj is javaScript function header. Obj must be a non-null String and match "^function[ ]?\\(.\*\)$"
static boolean	isJavaIdentifier(String str) Returns trus if str represents a valid Java identifier.
static boolean	isJsonKeyword(String input, JsonConfig jsonConfig)
static boolean	isNull(Object obj) Tests if the obj is a javaScript null.
static boolean	isNumber(Class clazz) Tests if Class represents a primitive number or wrapper.
static boolean	isNumber(Object obj) Tests if obj is a primitive number or wrapper.
static boolean	isObject(Object obj) Tests if obj is not a boolean, number, string or array.
static boolean	isString(Class clazz) Tests if Class represents a String or a char
static boolean	isString(Object obj) Tests if obj is a String or a char
static boolean	mayBeJSON(String string) Tests if the String possibly represents a valid JSON String. Valid JSON strings are: "null" starts with "[" and ends with "]" starts with "{" and ends with "}"
static DynaBean	newDynaBean(JSONObject jsonObject) Creates a new MorphDynaBean from a JSONObject.
static DynaBean	newDynaBean(JSONObject jsonObject, JsonConfig jsonConfig) Creates a new MorphDynaBean from a JSONObject.
static String	numberToString(Number n) Produce a string from a Number.
static String	quote(String string) Produce a string in double quotes with backslash sequences in all the right places.
static String	stripQuotes(String input) Strips any single-quotes or double-quotes from both sides of the string.
static void	testValidity(Object o) Throw an exception if the object is an NaN or infinite number.
static Number	transformNumber(Number input) Transforms a Number into a valid javascript number. Float gets promoted to Double. Byte and Short get promoted to Integer. Long gets downgraded to Integer if possible.
static String	valueToString(Object value) Make a JSON text of an Object value.
static String	valueToString(Object value, int indentFactor, int indent) Make a prettyprinted JSON text of an object value.

Methods inherited from class java.lang.Object

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

Field Detail

DOUBLE_QUOTE

public static final String DOUBLE_QUOTE

Constant for char "

See Also:

Constant Field Values

SINGLE_QUOTE

public static final String SINGLE_QUOTE

Constant for char '

See Also:

Constant Field Values

Method Detail

convertToJavaIdentifier

public static String convertToJavaIdentifier(String key)

Transforms the string into a valid Java Identifier.
The default strategy is JavaIdentifierTransformer.NOOP

Throws:

JSONException - if the string can not be transformed.

convertToJavaIdentifier

public static String convertToJavaIdentifier(String key,
                                             JsonConfig jsonConfig)

Transforms the string into a valid Java Identifier.
The default strategy is JavaIdentifierTransformer.NOOP

Throws:

JSONException - if the string can not be transformed.

doubleToString

public static String doubleToString(double d)

Produce a string from a double. The string "null" will be returned if the number is not finite.

Parameters:

d - A double.

Returns:

A String.

getFunctionBody

public static String getFunctionBody(String function)

Returns the body of a function literal.

getFunctionParams

public static String getFunctionParams(String function)

Returns the params of a function literal.

getInnerComponentType

public static Class getInnerComponentType(Class type)

Returns the inner-most component type of an Array.

getMorpherRegistry

public static MorpherRegistry getMorpherRegistry()

Returns the singleton MorpherRegistry.

getProperties

public static Map getProperties(JSONObject jsonObject)

Creates a Map with all the properties of the JSONObject.

getTypeClass

public static Class getTypeClass(Object obj)

Returns the JSON type.
Values are Object, String, Boolean, Number(subclasses) & JSONFunction.

hashCode

public static int hashCode(Object value)

Returns the hashcode of value.
If null it will return JSONNull.getInstance().hashCode().
If value is JSON, JSONFunction or String, value.hashCode is returned, otherwise the value is transformed to a String an its hashcode is returned.

isArray

public static boolean isArray(Class clazz)

Tests if a Class represents an array or Collection.

isArray

public static boolean isArray(Object obj)

Tests if obj is an array or Collection.

isBoolean

public static boolean isBoolean(Class clazz)

Tests if Class represents a Boolean or primitive boolean

isBoolean

public static boolean isBoolean(Object obj)

Tests if obj is a Boolean or primitive boolean

isDouble

public static boolean isDouble(Class clazz)

Tests if Class represents a primitive double or wrapper.

isFunction

public static boolean isFunction(Object obj)

Tests if obj is javaScript function.
Obj must be a non-null String and match "^function[ ]?\\(.\*\)[ ]?\\{.\*\}$"

isFunctionHeader

public static boolean isFunctionHeader(Object obj)

Tests if obj is javaScript function header.
Obj must be a non-null String and match "^function[ ]?\\(.\*\)$"

isJavaIdentifier

public static boolean isJavaIdentifier(String str)

Returns trus if str represents a valid Java identifier.

isNull

public static boolean isNull(Object obj)

Tests if the obj is a javaScript null.

isNumber

public static boolean isNumber(Class clazz)

Tests if Class represents a primitive number or wrapper.

isNumber

public static boolean isNumber(Object obj)

Tests if obj is a primitive number or wrapper.

isObject

public static boolean isObject(Object obj)

Tests if obj is not a boolean, number, string or array.

isString

public static boolean isString(Class clazz)

Tests if Class represents a String or a char

isString

public static boolean isString(Object obj)

Tests if obj is a String or a char

mayBeJSON

public static boolean mayBeJSON(String string)

Tests if the String possibly represents a valid JSON String.
Valid JSON strings are:

• "null"
• starts with "[" and ends with "]"
• starts with "{" and ends with "}"

newDynaBean

public static DynaBean newDynaBean(JSONObject jsonObject)

Creates a new MorphDynaBean from a JSONObject. The MorphDynaBean will have all the properties of the original JSONObject with the most accurate type. Values of properties are not copied.

newDynaBean

public static DynaBean newDynaBean(JSONObject jsonObject,
                                   JsonConfig jsonConfig)

Creates a new MorphDynaBean from a JSONObject. The MorphDynaBean will have all the properties of the original JSONObject with the most accurate type. Values of properties are not copied.

numberToString

public static String numberToString(Number n)

Produce a string from a Number.

Parameters:

n - A Number

Returns:

A String.

Throws:

JSONException - If n is a non-finite number.

quote

public static String quote(String string)

Produce a string in double quotes with backslash sequences in all the right places. A backslash will be inserted within CAUTION: if string represents a javascript function, translation of characters will not take place. This will produce a non-conformant JSON text.

Parameters:

string - A String

Returns:

A String correctly formatted for insertion in a JSON text.

stripQuotes

public static String stripQuotes(String input)

Strips any single-quotes or double-quotes from both sides of the string.

hasQuotes

public static boolean hasQuotes(String input)

Returns true if the input has single-quotes or double-quotes at both sides.

isJsonKeyword

public static boolean isJsonKeyword(String input,
                                    JsonConfig jsonConfig)

testValidity

public static void testValidity(Object o)

Throw an exception if the object is an NaN or infinite number.

Parameters:

o - The object to test.

Throws:

JSONException - If o is a non-finite number.

transformNumber

public static Number transformNumber(Number input)

Transforms a Number into a valid javascript number.
Float gets promoted to Double.
Byte and Short get promoted to Integer.
Long gets downgraded to Integer if possible.

valueToString

public static String valueToString(Object value)

Make a JSON text of an Object value. If the object has an value.toJSONString() method, then that method will be used to produce the JSON text. The method is required to produce a strictly conforming text. If the object does not contain a toJSONString method (which is the most common case), then a text will be produced by the rules.

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

Parameters:

value - The value to be serialized.

Returns:

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

Throws:

JSONException - If the value is or contains an invalid number.

valueToString

public static String valueToString(Object value,
                                   int indentFactor,
                                   int indent)

Make a prettyprinted JSON text of an object value.

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

Parameters:

value - The value to be serialized.

indentFactor - The number of spaces to add to each level of indentation.

indent - The indentation of the top level.

Returns:

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

Throws:

JSONException - If the object contains an invalid number.