io.netty.handler.codec.json

Class JsonObjectDecoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.handler.codec.ByteToMessageDecoder

io.netty.handler.codec.json.JsonObjectDecoder

All Implemented Interfaces:

ChannelHandler

public class JsonObjectDecoder
extends ByteToMessageDecoder

Splits a byte stream of JSON objects and arrays into individual objects/arrays and passes them up the ChannelPipeline. This class does not do any real parsing or validation. A sequence of bytes is considered a JSON object/array if it contains a matching number of opening and closing braces/brackets. It's up to a subsequent ChannelHandler to parse the JSON text into a more usable form i.e. a POJO.

Nested Class Summary

Nested classes/interfaces inherited from class io.netty.handler.codec.ByteToMessageDecoder

ByteToMessageDecoder.Cumulator

Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

ChannelHandler.Sharable, ChannelHandler.Skip

Field Summary

Fields inherited from class io.netty.handler.codec.ByteToMessageDecoder

COMPOSITE_CUMULATOR, MERGE_CUMULATOR

Constructor Summary

Constructors

Constructor and Description
JsonObjectDecoder()
JsonObjectDecoder(boolean streamArrayElements)
JsonObjectDecoder(int maxObjectLength)
JsonObjectDecoder(int maxObjectLength, boolean streamArrayElements)

Method Summary

Methods

Modifier and Type	Method and Description
protected void	decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) Decode the from one ByteBuf to an other.
protected ByteBuf	extractObject(ChannelHandlerContext ctx, ByteBuf buffer, int index, int length) Override this method if you want to filter the json objects/arrays that get passed through the pipeline.

Methods inherited from class io.netty.handler.codec.ByteToMessageDecoder

actualReadableBytes, callDecode, channelInactive, channelRead, channelReadComplete, decodeLast, handlerRemoved, handlerRemoved0, internalBuffer, isSingleDecode, setCumulator, setSingleDecode

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

bind, channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, close, connect, deregister, disconnect, exceptionCaught, flush, handlerAdded, isSharable, read, userEventTriggered, write

Methods inherited from class java.lang.Object

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

Constructor Detail

JsonObjectDecoder

public JsonObjectDecoder()

JsonObjectDecoder

public JsonObjectDecoder(int maxObjectLength)

JsonObjectDecoder

public JsonObjectDecoder(boolean streamArrayElements)

JsonObjectDecoder

public JsonObjectDecoder(int maxObjectLength,
                 boolean streamArrayElements)

Parameters:

maxObjectLength - maximum number of bytes a JSON object/array may use (including braces and all). Objects exceeding this length are dropped and an TooLongFrameException is thrown.

streamArrayElements - if set to true and the "top level" JSON object is an array, each of its entries is passed through the pipeline individually and immediately after it was fully received, allowing for arrays with "infinitely" many elements.

Method Detail

decode

protected void decode(ChannelHandlerContext ctx,
          ByteBuf in,
          List<Object> out)
               throws Exception

Description copied from class: ByteToMessageDecoder

Decode the from one ByteBuf to an other. This method will be called till either the input ByteBuf has nothing to read when return from this method or till nothing was read from the input ByteBuf.

Specified by:

decode in class ByteToMessageDecoder

Parameters:

ctx - the ChannelHandlerContext which this ByteToMessageDecoder belongs to

in - the ByteBuf from which to read data

out - the List to which decoded messages should be added

Throws:

Exception - is thrown if an error accour

extractObject

protected ByteBuf extractObject(ChannelHandlerContext ctx,
                    ByteBuf buffer,
                    int index,
                    int length)

Override this method if you want to filter the json objects/arrays that get passed through the pipeline.