Netty Example Client

NettyExampleCLient.java

import java.net.InetSocketAddress;
import java.util.concurrent.Executors;
import org.jboss.netty.bootstrap.ClientBootstrap;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.channel.ChannelFactory;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelHandler;
import org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory;
import org.jboss.netty.handler.codec.frame.DelimiterBasedFrameDecoder;
import org.jboss.netty.handler.codec.frame.Delimiters;

public class NettyExampleClient extends SimpleChannelHandler {
    private String [] SYMBOLS = new String[]{"SPY", "BAC", "XOM"};

    private void subscribe(ChannelHandlerContext ctx) {
        for (String symbol : SYMBOLS)
            ctx.getChannel().write('w' + symbol);
    }

    private void processQuote(String ... fields) {}

    @Override
    public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
        ChannelBuffer buf = ((ChannelBuffer) e.getMessage()).copy();
        String message = new String(buf.array());
        String [] fields = message.split(",");
        if (fields.length > 0) {
            if (fields[0].equals("Q")) {
                this.processQuote(fields);
            } else if (fields[0].equals("S")) {
                if (fields[1].equals("CUST")) 
                    this.subscribe(ctx);
            }
        }

        ctx.sendUpstream(e);
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
        e.getCause().printStackTrace();
        e.getChannel().close();
    }

    public static void main(String[] args) {
        ChannelFactory factory = new NioClientSocketChannelFactory(
                Executors.newCachedThreadPool(),
                Executors.newCachedThreadPool());

        ClientBootstrap bootstrap = new ClientBootstrap(factory);

        bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
            public ChannelPipeline getPipeline() {
                return Channels.pipeline(
                    new DelimiterBasedFrameDecoder(500,Delimiters.lineDelimiter()),
                    new NettyExampleClient());
            }
        });

        bootstrap.setOption("tcpNoDelay", true);
        bootstrap.setOption("keepAlive", true);

        ChannelFuture future = bootstrap.connect(new InetSocketAddress("localhost", 5009));
        future.awaitUninterruptibly();
        if (!future.isSuccess()) {
            future.getCause().printStackTrace();
        }
        future.getChannel().getCloseFuture().awaitUninterruptibly();
        factory.releaseExternalResources();
    }
}