io.netty.channel.ChannelHandlerAdapter Maven / Gradle / Ivy
/*
* Copyright 2013 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.channel;
/**
* Skelton implementation of a {@link ChannelHandler}.
*/
public abstract class ChannelHandlerAdapter implements ChannelHandler {
// Not using volatile because it's used only for a sanity check.
boolean added;
/**
* Return {@code true} if the implementation is {@link Sharable} and so can be added
* to different {@link ChannelPipeline}s.
*/
final boolean isSharable() {
return getClass().isAnnotationPresent(Sharable.class);
}
/**
* Do nothing by default, sub-classes may override this method.
*/
@Override
public void beforeAdd(ChannelHandlerContext ctx) throws Exception {
// NOOP
}
/**
* Do nothing by default, sub-classes may override this method.
*/
@Override
public void afterAdd(ChannelHandlerContext ctx) throws Exception {
// NOOP
}
/**
* Do nothing by default, sub-classes may override this method.
*/
@Override
public void beforeRemove(ChannelHandlerContext ctx) throws Exception {
// NOOP
}
/**
* Do nothing by default, sub-classes may override this method.
*/
@Override
public void afterRemove(ChannelHandlerContext ctx) throws Exception {
// NOOP
}
/**
* Calls {@link ChannelHandlerContext#fireExceptionCaught(Throwable)} to forward
* to the next {@link ChannelHandler} in the {@link ChannelPipeline}.
*
* Sub-classes may override this method to change behavior.
*/
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
throws Exception {
ctx.fireExceptionCaught(cause);
}
}