Package org.eclipse.jetty.util.ajax

Class AsyncJSON

java.lang.Object

org.eclipse.jetty.util.ajax.AsyncJSON

public class AsyncJSON
extends java.lang.Object

A non-blocking JSON parser that can parse partial JSON strings.

Usage:

 AsyncJSON parser = new AsyncJSON.Factory().newAsyncJSON();

 // Feed the parser with partial JSON string content.
 parser.parse(chunk1);
 parser.parse(chunk2);

 // Tell the parser that the JSON string content
 // is terminated and get the JSON object back.
 Map<String, Object> object = parser.complete();
 

After the call to complete() the parser can be reused to parse another JSON string.

Custom objects can be created by specifying a "class" or "x-class" field:

 String json = """
 {
   "x-class": "com.acme.Person",
   "firstName": "John",
   "lastName": "Doe",
   "age": 42
 }
 """

 parser.parse(json);
 com.acme.Person person = parser.complete();
 

Class com.acme.Person must either implement JSON.Convertible, or be mapped with a JSON.Convertor via AsyncJSON.Factory.putConvertor(String, Convertor).

JSON arrays are by default represented with a List<Object>, but the Java representation can be customized via AsyncJSON.Factory.setArrayConverter(Function).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	AsyncJSON.Context	The state of JSON parsing.
static class	AsyncJSON.Factory	The factory that creates AsyncJSON instances.
private static class	AsyncJSON.Frame
private static class	AsyncJSON.FrameStack
private static class	AsyncJSON.NumberBuilder
private static class	AsyncJSON.State

Field Summary

Fields

Modifier and Type	Field	Description
private java.util.List<java.nio.ByteBuffer>	chunks
private AsyncJSON.Factory	factory
private AsyncJSON.NumberBuilder	numberBuilder
private AsyncJSON.FrameStack	stack
private Utf8StringBuilder	stringBuilder
private static java.lang.Object	UNSET

Constructor Summary

Constructors

Constructor	Description
AsyncJSON(AsyncJSON.Factory factory)

Method Summary

Modifier and Type	Method	Description
<R> R	complete()	Signals to the parser that the parse data is complete, and returns the object parsed from the JSON chunks passed to the parse() methods.
private java.lang.Object	convertArray(java.util.List<?> array)
private java.lang.Object	convertObject(java.lang.String fieldName, java.util.Map<java.lang.String,java.lang.Object> object)
private java.lang.Object	convertObject(java.util.Map<java.lang.String,java.lang.Object> object)
private java.lang.Object	end()
private byte	hexToByte(java.nio.ByteBuffer buffer, byte currentByte)
(package private) boolean	isEmpty()
private static boolean	isWhitespace(byte ws)
protected java.util.List<java.lang.Object>	newArray(AsyncJSON.Context context)	When a JSON [ is encountered during parsing, this method is called to create a new List instance.
protected java.lang.RuntimeException	newInvalidJSON(java.nio.ByteBuffer buffer, java.lang.String message)
protected java.util.Map<java.lang.String,java.lang.Object>	newObject(AsyncJSON.Context context)	When a JSON { is encountered during parsing, this method is called to create a new Map instance.
boolean	parse(byte[] bytes)	Feeds the parser with the given bytes chunk.
boolean	parse(byte[] bytes, int offset, int length)	Feeds the parser with the given bytes chunk.
boolean	parse(java.nio.ByteBuffer buffer)	Feeds the parser with the given buffer chunk.
private boolean	parseAny(java.nio.ByteBuffer buffer)
private boolean	parseArray(java.nio.ByteBuffer buffer)
private boolean	parseEscape(java.nio.ByteBuffer buffer)
private boolean	parseEscapeCharacter(char escape)
private boolean	parseFalse(java.nio.ByteBuffer buffer)
private void	parseFalseCharacter(java.nio.ByteBuffer buffer, int index)
private boolean	parseNull(java.nio.ByteBuffer buffer)
private void	parseNullCharacter(java.nio.ByteBuffer buffer, int index)
private boolean	parseNumber(java.nio.ByteBuffer buffer)
private boolean	parseObject(java.nio.ByteBuffer buffer)
private boolean	parseObjectField(java.nio.ByteBuffer buffer)
private boolean	parseObjectFieldName(java.nio.ByteBuffer buffer)
private boolean	parseObjectFieldValue(java.nio.ByteBuffer buffer)
private boolean	parseString(java.nio.ByteBuffer buffer)
private boolean	parseTrue(java.nio.ByteBuffer buffer)
private void	parseTrueCharacter(java.nio.ByteBuffer buffer, int index)
private boolean	parseUnicode(java.nio.ByteBuffer buffer)
private void	reset()
private JSON.Convertible	toConvertible(java.lang.String className)

Methods inherited from class java.lang.Object

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

Field Detail

UNSET

private static final java.lang.Object UNSET

stack

private final AsyncJSON.FrameStack stack

numberBuilder

private final AsyncJSON.NumberBuilder numberBuilder

stringBuilder

private final Utf8StringBuilder stringBuilder

factory

private final AsyncJSON.Factory factory

chunks

private java.util.List<java.nio.ByteBuffer> chunks

Constructor Detail

AsyncJSON

public AsyncJSON(AsyncJSON.Factory factory)

Method Detail

isEmpty

boolean isEmpty()

parse

public boolean parse(byte[] bytes)

Feeds the parser with the given bytes chunk.

Parameters:

bytes - the bytes to parse

Returns:

whether the JSON parsing was complete

Throws:

java.lang.IllegalArgumentException - if the JSON is malformed

parse

public boolean parse(byte[] bytes,
                     int offset,
                     int length)

Feeds the parser with the given bytes chunk.

Parameters:

bytes - the bytes to parse

offset - the offset to start parsing from

length - the number of bytes to parse

Returns:

whether the JSON parsing was complete

Throws:

java.lang.IllegalArgumentException - if the JSON is malformed

parse

public boolean parse(java.nio.ByteBuffer buffer)

Feeds the parser with the given buffer chunk.

Parameters:

buffer - the buffer to parse

Returns:

whether the JSON parsing was complete

Throws:

java.lang.IllegalArgumentException - if the JSON is malformed

complete

public <R> R complete()

Signals to the parser that the parse data is complete, and returns the object parsed from the JSON chunks passed to the parse() methods.

Type Parameters:

R - the type the result is cast to

Returns:

the result of the JSON parsing

Throws:

java.lang.IllegalArgumentException - if the JSON is malformed

java.lang.IllegalStateException - if the no JSON was passed to the parse() methods

newObject

protected java.util.Map<java.lang.String,java.lang.Object> newObject(AsyncJSON.Context context)

When a JSON { is encountered during parsing, this method is called to create a new Map instance.

Subclasses may override to return a custom Map instance.

Parameters:

context - the parsing context

Returns:

a Map instance

newArray

protected java.util.List<java.lang.Object> newArray(AsyncJSON.Context context)

When a JSON [ is encountered during parsing, this method is called to create a new List instance.

Subclasses may override to return a custom List instance.

Parameters:

context - the parsing context

Returns:

a List instance

end

private java.lang.Object end()

reset

private void reset()

parseAny

private boolean parseAny(java.nio.ByteBuffer buffer)

parseNull

private boolean parseNull(java.nio.ByteBuffer buffer)

parseNullCharacter

private void parseNullCharacter(java.nio.ByteBuffer buffer,
                                int index)

parseTrue

private boolean parseTrue(java.nio.ByteBuffer buffer)

parseTrueCharacter

private void parseTrueCharacter(java.nio.ByteBuffer buffer,
                                int index)

parseFalse

private boolean parseFalse(java.nio.ByteBuffer buffer)

parseFalseCharacter

private void parseFalseCharacter(java.nio.ByteBuffer buffer,
                                 int index)

parseNumber

private boolean parseNumber(java.nio.ByteBuffer buffer)

parseString

private boolean parseString(java.nio.ByteBuffer buffer)

parseEscape

private boolean parseEscape(java.nio.ByteBuffer buffer)

parseEscapeCharacter

private boolean parseEscapeCharacter(char escape)

parseUnicode

private boolean parseUnicode(java.nio.ByteBuffer buffer)

hexToByte

private byte hexToByte(java.nio.ByteBuffer buffer,
                       byte currentByte)

parseArray

private boolean parseArray(java.nio.ByteBuffer buffer)

parseObject

private boolean parseObject(java.nio.ByteBuffer buffer)

parseObjectField

private boolean parseObjectField(java.nio.ByteBuffer buffer)

parseObjectFieldName

private boolean parseObjectFieldName(java.nio.ByteBuffer buffer)

parseObjectFieldValue

private boolean parseObjectFieldValue(java.nio.ByteBuffer buffer)

convertArray

private java.lang.Object convertArray(java.util.List<?> array)

convertObject

private java.lang.Object convertObject(java.util.Map<java.lang.String,java.lang.Object> object)

convertObject

private java.lang.Object convertObject(java.lang.String fieldName,
                                       java.util.Map<java.lang.String,java.lang.Object> object)

toConvertible

private JSON.Convertible toConvertible(java.lang.String className)

newInvalidJSON

protected java.lang.RuntimeException newInvalidJSON(java.nio.ByteBuffer buffer,
                                                    java.lang.String message)

isWhitespace

private static boolean isWhitespace(byte ws)