org.openjax.json

Class JsonUtil

java.lang.Object

org.openjax.json.JsonUtil

public final class JsonUtil
extends Object

Utility functions for operations pertaining to JSON.

Method Summary

Modifier and Type	Method and Description
static StringBuilder	escape(String str) Escapes characters in the specified string that must be escaped as defined in RFC 4627, Section 2.5.
static boolean	isStructural(int ch) Tests whether ch is a structural char, which is one of:
static boolean	isWhitespace(int ch) Tests whether the specified int is JSON whitespace char, which is one of:
static <T extends Number> T	parseNumber(Class<T> type, String str) Parses a number from the specified string by the rules defined in RFC 4627, Section 2.4.
static String	unescape(String str) Unescapes string-literal unicode (" ") and two-character ("\n") escape codes into UTF-8 as defined in RFC 4627, Section 2.5.
static String	unescapeForString(String str) Unescapes string-literal unicode (" ") and two-character ("\n") escape codes, except for the double quote ("\"") and reverse solidus ("\\"), into UTF-8 as defined in RFC 4627, Section 2.5.

Methods inherited from class java.lang.Object

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

Method Detail

isStructural

public static boolean isStructural(int ch)

Tests whether ch is a structural char, which is one of:

 { } [ ] : ,
 

Parameters:

ch - The char to test.

Returns:

true if ch is a structural char, otherwise false.

isWhitespace

public static boolean isWhitespace(int ch)

Tests whether the specified int is JSON whitespace char, which is one of:

  ' ',  '\n',  '\r', or  '\t'
 

Parameters:

ch - The int to test.

Returns:

true if the specified int is an ANSI whitespace char; otherwise false.

See Also:

RFC4627

parseNumber

public static <T extends Number> T parseNumber(Class<T> type,
                                               String str)
                                        throws JsonParseException

Parses a number from the specified string by the rules defined in RFC 4627, Section 2.4.

Type Parameters:

T - The type parameter for the return instance.

Parameters:

type - The class of the return instance.

str - The string to parse.

Returns:

An instance of class type representing the parsed string.

Throws:

JsonParseException - If a parsing error has occurred.

IllegalArgumentException - If the specified string is empty, or if an instance of the specific class type does not define <init>(String), valueOf(String), or fromString(String).

NullPointerException - If the specified string is null.

escape

public static StringBuilder escape(String str)

Escapes characters in the specified string that must be escaped as defined in RFC 4627, Section 2.5. This includes quotation mark ("\""), reverse solidus ("\\"), and the control characters (U+0000 through U+001F).

This method escapes the following characters in string-literal two-character form:

 {'\n', '\r', '\t', '\b', '\f'} -> {"\\n", "\\r", "\\t", "\\b", "\\f"}
 

Parameters:

str - The string to be escaped.

Returns:

The escaped representation of the specified string.

See Also:

unescape(String)

unescapeForString

public static String unescapeForString(String str)

Unescapes string-literal unicode (" ") and two-character ("\n") escape codes, except for the double quote ("\"") and reverse solidus ("\\"), into UTF-8 as defined in RFC 4627, Section 2.5.

This method deliberately excludes the double quote ("\"") and reverse solidus ("\\"), as these characters are necessary to be able to differentiate the double quote from string boundaries, and thus the reverse solidus from the escape character.

Parameters:

str - The string to be unescaped.

Returns:

The unescaped representation of the specified string, with the escaped form of the double quote ("\"") and reverse solidus ("\\") preserved.

See Also:

unescape(String)

unescape

public static String unescape(String str)

Unescapes string-literal unicode (" ") and two-character ("\n") escape codes into UTF-8 as defined in RFC 4627, Section 2.5.

Parameters:

str - The string to be unescaped.

Returns:

The unescaped representation of the specified string.