io.netty.channel

Class SimpleChannelInboundHandler<I>

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.SimpleChannelInboundHandler<I>

All Implemented Interfaces:

ChannelHandler

public abstract class SimpleChannelInboundHandler<I>
extends ChannelHandlerAdapter

ChannelHandler which allows to explicit only handle a specific type of messages. For example here is an implementation which only handle String messages.

     public class StringHandler extends
             SimpleChannelInboundHandler<String> {

         @Override
         protected void messageReceived(ChannelHandlerContext ctx, String message)
                 throws Exception {
             System.out.println(message);
         }
     }
 

Be aware that depending of the constructor parameters it will release all handled messages by pass them to ReferenceCountUtil.release(Object). In this case you may need to use ReferenceCountUtil.retain(Object) if you pass the object to the next handler in the ChannelPipeline.

Backward compatibility consideration

Since 5.0, channelRead0(ChannelHandlerContext, I) has been renamed to #messageReceived(ChannelHandlerContext, I).

Nested Class Summary

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

ChannelHandler.Sharable, ChannelHandler.Skip

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SimpleChannelInboundHandler()
protected	SimpleChannelInboundHandler(boolean autoRelease) Create a new instance which will try to detect the types to match out of the type parameter of the class.
protected	SimpleChannelInboundHandler(Class<? extends I> inboundMessageType)
protected	SimpleChannelInboundHandler(Class<? extends I> inboundMessageType, boolean autoRelease) Create a new instance

Method Summary

Methods

Modifier and Type	Method and Description
boolean	acceptInboundMessage(Object msg) Returns true if the given message should be handled.
void	channelRead(ChannelHandlerContext ctx, Object msg) Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelHandler in the ChannelPipeline.
protected abstract void	messageReceived(ChannelHandlerContext ctx, I msg) Is called for each message of type I.

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

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

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleChannelInboundHandler

protected SimpleChannelInboundHandler()

See Also:

#SimpleChannelInboundHandler(boolean)} with {@code true} as boolean parameter.

SimpleChannelInboundHandler

protected SimpleChannelInboundHandler(boolean autoRelease)

Create a new instance which will try to detect the types to match out of the type parameter of the class.

Parameters:

autoRelease - true if handled messages should be released automatically by pass them to ReferenceCountUtil.release(Object).

SimpleChannelInboundHandler

protected SimpleChannelInboundHandler(Class<? extends I> inboundMessageType)

See Also:

#SimpleChannelInboundHandler(Class, boolean)} with {@code true} as boolean value.

SimpleChannelInboundHandler

protected SimpleChannelInboundHandler(Class<? extends I> inboundMessageType,
                           boolean autoRelease)

Create a new instance

Parameters:

inboundMessageType - The type of messages to match

autoRelease - true if handled messages should be released automatically by pass them to ReferenceCountUtil.release(Object).

Method Detail

acceptInboundMessage

public boolean acceptInboundMessage(Object msg)
                             throws Exception

Returns true if the given message should be handled. If false it will be passed to the next ChannelHandler in the ChannelPipeline.

Throws:

Exception

channelRead

public void channelRead(ChannelHandlerContext ctx,
               Object msg)
                 throws Exception

Description copied from class: ChannelHandlerAdapter

Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

Specified by:

channelRead in interface ChannelHandler

Overrides:

channelRead in class ChannelHandlerAdapter

Throws:

Exception

messageReceived

protected abstract void messageReceived(ChannelHandlerContext ctx,
                   I msg)
                                 throws Exception

Is called for each message of type I.

Parameters:

ctx - the ChannelHandlerContext which this SimpleChannelInboundHandler belongs to

msg - the message to handle

Throws:

Exception - is thrown if an error occurred