package com.manning.nettyinaction.chapter8;
import io.netty.buffer.ByteBuf;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.LineBasedFrameDecoder;
/**
* Listing 8.9 of <i>Netty in Action</i>
*
* @author <a href="mailto:nmaurer@redhat.com">Norman Maurer</a>
*/
public class CmdHandlerInitializer extends ChannelInitializer<Channel> {
@Override
protected void initChannel(Channel ch) throws Exception {
ChannelPipeline pipeline = ch.pipeline();
pipeline.addLast(new CmdDecoder(65 * 1024));
pipeline.addLast(new CmdHandler());
}
public static final class Cmd {
private final ByteBuf name;
private final ByteBuf args;
public Cmd(ByteBuf name, ByteBuf args) {
this.name = name;
this.args = args;
}
public ByteBuf name() {
return name;
}
public ByteBuf args() {
return args;
}
}
public static final class CmdDecoder extends LineBasedFrameDecoder {
public CmdDecoder(int maxLength) {
super(maxLength);
}
@Override
protected Object decode(ChannelHandlerContext ctx, ByteBuf buffer) throws Exception {
ByteBuf frame = (ByteBuf) super.decode(ctx, buffer);
if (frame == null) {
return null;
}
int index = frame.indexOf(frame.readerIndex(), frame.writerIndex(), (byte) ' ');
return new Cmd(frame.slice(frame.readerIndex(), index), frame.slice(index +1, frame.writerIndex()));
}
}
public static final class CmdHandler extends SimpleChannelInboundHandler<Cmd> {
@Override
public void channelRead0(ChannelHandlerContext ctx, Cmd msg) throws Exception {
// Do something with the command
}
}
}