Module org.bzdev.base

Package org.bzdev.util

Class JSUtilities.JSON

java.lang.Object

org.bzdev.util.JSUtilities.JSON

Direct Known Subclasses:

JSUtilities.YAML, NJSUtilities.JSON

Enclosing class:

JSUtilities

public static class JSUtilities.JSON
extends Object

Methods for parsing and generating JSON. All the public methods of this class are static. An extended syntax is used for parsing (but not for writing):

• Comments consist of the sequence '//', not within a string, and contain all characters up to the end of a line. Comments will be silently dropped and are allowed only where whitespace is allowed.
• For a JSON object in a key/value pair, quoting the key is optional when the key is syntactically a Java identifier.

These extensions are useful when a file containing JSON-formated values is used as an input to a program. The object returned by the parser can be used to configure a named-object factory (using the syntax described in the documentation for NamedObjectFactory<F extends NamedObjectFactory<F,NMR,NMD,OBJ>,NMR extends ObjectNamerOps<NMD>,NMD extends NamedObjectOps,OBJ extends NMD>.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	JSUtilities.JSON.Parser	Parser support class for JSON.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	JSON()	Constructor.

Method Summary

Modifier and Type	Method	Description
static Object	parse(char[] buffer)	JSON parser that reads JSON-formated text from a character array.
static Object	parse(InputStream is, String charsetName)	JSON parser that reads JSON-formatted text from an InputStream given a String providing the name of a character set.
static Object	parse(InputStream is, Charset cs)	JSON parser that reads JSON-formatted text from an InputStream given a Charset.
static Object	parse(InputStream is, CharsetDecoder dec)	JSON parser that reads JSON-formatted text from an InputStream given a CharsetDecoder.
static Object	parse(Reader r)	JSON parser that reads JSON-formated text from a Reader.
static Object	parse(String s)	JSON parser that reads JSON-formated text from a String.
static String	quote(String s)	Encode a string using JSON escape sequences.
protected void	write(Writer w, Boolean object)	Write an object whose type is Boolean.
protected void	write(Writer w, Number object)	Write an object whose type is Number.
protected void	write(Writer w, Object object)	Write an object.
protected void	write(Writer w, String object)	Write an object whose type is String.
protected void	write(Writer w, JSArray object)	Write an object whose type is JSArray.
protected void	write(Writer w, JSObject object)	Write an object whose type is JSObject.
static void	writeTo(Writer w, Object object)	Write a JSON representation of an object.

Methods inherited from class java.lang.Object

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

Constructor Details

JSON

protected JSON()

Constructor.

Method Details

writeTo

public static void writeTo(Writer w,
 Object object)
                    throws IOException

Write a JSON representation of an object. The type of the object may be JSObject, JSArray, String, Number, or Boolean.

Parameters:

w - a writer

object - the object to write

Throws:

IOException - an error occurred while writing

write

protected void write(Writer w,
 Object object)
              throws IOException

Write an object. This method dispatches the operation to methods for specific object types.

Parameters:

w - the writer

object - the object

Throws:

IOException - if an IO error occurred

write

protected void write(Writer w,
 JSObject object)
              throws IOException

Write an object whose type is JSObject.

Parameters:

w - the writer

object - the object

Throws:

IOException - if an IO error occurred

write

protected void write(Writer w,
 JSArray object)
              throws IOException

Write an object whose type is JSArray.

Parameters:

w - the writer

object - the object

Throws:

IOException - if an IO error occurred

write

protected void write(Writer w,
 Boolean object)
              throws IOException

Write an object whose type is Boolean.

Parameters:

w - the writer

object - the object

Throws:

IOException - if an IO error occurred

write

protected void write(Writer w,
 Number object)
              throws IOException

Write an object whose type is Number.

Parameters:

w - the writer

object - the object

Throws:

IOException - if an IO error occurred

write

protected void write(Writer w,
 String object)
              throws IOException

Write an object whose type is String.

Parameters:

w - the writer

object - the object

Throws:

IOException - if an IO error occurred

quote

public static String quote(String s)

Encode a string using JSON escape sequences.

Parameters:

s - the string to encode

Returns:

the encoded string, including the delimiting double quotes; the token null if the argument is null

parse

public static Object parse(InputStream is,
 String charsetName)
                    throws IOException,
UnsupportedEncodingException

JSON parser that reads JSON-formatted text from an InputStream given a String providing the name of a character set. The result's type, if the result is not null, is either JSObject, JSArray, String, Number, or Boolean.

Parameters:

is - the input stream (containing a JSON value)

charsetName - the name of the charset used by the input stream

Returns:

either a JSObject, JSArray, String, Number, Boolean, or null

Throws:

IOException - an error occurred while reading from the input stream

UnsupportedEncodingException - the charsetName does not match a known charset

parse

public static Object parse(InputStream is,
 CharsetDecoder dec)
                    throws IOException

JSON parser that reads JSON-formatted text from an InputStream given a CharsetDecoder. The result's type, if the result is not null, is either JSObject, JSArray, String, Number, or Boolean.

Parameters:

is - the input stream (containing a JSON value)

dec - the charset decoder used to turn the input stream into a sequence of characters

Returns:

either a JSObject, JSArray, String, Number, Boolean, or null

Throws:

IOException - an error occurred while reading from the input stream

parse

public static Object parse(InputStream is,
 Charset cs)
                    throws IOException

JSON parser that reads JSON-formatted text from an InputStream given a Charset. The result's type, if the result is not null, is either JSObject, JSArray, String, Number, or Boolean.

Parameters:

is - the input stream (containing a JSON value)

cs - the charset for the input stream

Returns:

either a JSObject, JSArray, String, Number, Boolean, or null

Throws:

IOException - an error occurred while reading from the input stream

parse

public static Object parse(char[] buffer)
                    throws IOException

JSON parser that reads JSON-formated text from a character array. The result's type, if the result is not null, is either JSObject, JSArray, String, Number, or Boolean.

Parameters:

buffer - the input character sequence (containing a JSON value)

Returns:

either a JSObject, JSArray, String, Number, Boolean, or null

Throws:

IOException - an error occurred while reading from the input stream

parse

public static Object parse(String s)
                    throws IOException

JSON parser that reads JSON-formated text from a String. The result's type, if the result is not null, is either JSObject, JSArray, String, Number, or Boolean.

Parameters:

s - the input string (containing a JSON value)

Returns:

either a JSObject, JSArray, String, Number, Boolean, or null

Throws:

IOException - an error occurred while reading from the input stream

parse

public static Object parse(Reader r)
                    throws IOException

JSON parser that reads JSON-formated text from a Reader. The result's type, if the result is not null, is either JSObject, JSArray, String, Number, or Boolean.

Parameters:

r - the reader

Returns:

either a JSObject, JSArray, String, Number, Boolean, or null

Throws:

IOException - an error occurred while reading from the input stream