netty版本 4.1.9.Final

一、类介绍

1.ChannelPool ,连接池接口

2.SimpleChannelPool,实现ChannelPool接口，简单的连接池实现

3.FixedChannelPool,继承SimpleChannelPool，有大小限制的连接池实现

4.ChannelPoolMap,管理host与连接池映射的接口

5.AbstractChannelPoolMap,抽象类，实现ChannelPoolMap接口

二、具体使用

我们以http协议的实现来使用连接池，直接上代码

1.ClientPool

public class ClientPool{    //key为目标host，value为目标host的连接池    public ChannelPoolMap
    
      poolMap = null;    public ClientPool(){        init();    }    public void init(){        EventLoopGroup group = new NioEventLoopGroup();        final Bootstrap cb = new Bootstrap();        cb.group(group).channel(NioSocketChannel.class);        poolMap = new AbstractChannelPoolMap
     
      () {            @Override            protected FixedChannelPool newPool(InetSocketAddress key) {                return new FixedChannelPool(cb.remoteAddress(key), new ChannelPoolHandler() {                    public void channelReleased(Channel ch) throws Exception {                        System.out.println("22");                    }                    public void channelAcquired(Channel ch) throws Exception {                        System.out.println("33");                    }                    public void channelCreated(Channel ch) throws Exception {                        //可以在此绑定channel的handler                        ch.pipeline().addLast(new HttpClientCodec())                                .addLast(new HttpObjectAggregator(1024 * 1024))                                .addLast(new HttpBackendHandler());                    }                },20);//单个host连接池大小            }        };    }    public void getHttpClient(InetSocketAddress address,final FullHttpRequest msg) {        if(address == null){            throw new RuntimeException("InetSocketAddress can not be null");        }        final FixedChannelPool pool = this.poolMap.get(address);        Future
      
        f = pool.acquire();        future.addListener(new FutureListener
       
        () {            public void operationComplete(Future
        
          f) {                if (f.isSuccess()) {                    Channel ch = f.getNow();                    ChannelFuture lastWriteFuture = null;                    lastWriteFuture = ch.writeAndFlush(msg);                    // Wait until all messages are flushed before closing the channel.                    if (lastWriteFuture != null) {                        try {                            lastWriteFuture.sync();                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                    }                    pool.release(ch);                }            }        });    }}
        
       
      
     
    

2.HttpBackendHandler

public class HttpBackendHandler extends SimpleChannelInboundHandler
    
      {    public HttpBackendHandler() {    }    @Override    public void channelActive(ChannelHandlerContext ctx) throws Exception {        System.out.println("Backend Handler is Active!");        super.channelActive(ctx);    }    @Override    public void channelRead0(final ChannelHandlerContext ctx, FullHttpResponse msg) throws Exception {         //todo something    }        @Override    public void channelInactive(ChannelHandlerContext ctx) {        System.out.println("Backend Handler destroyed!");    }        @Override    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {        cause.printStackTrace();        if (ctx.channel().isActive()) {            ctx.channel().writeAndFlush(Unpooled.EMPTY_BUFFER).addListener(ChannelFutureListener.CLOSE);        }    }}
    

3.使用

public class NettyHttpClientPoolTest {    public static void main(String[] args){        ClientPool pool = new ClientPool();        InetSocketAddress address = new InetSocketAddress("127.0.0.1",8080;        FullHttpRequest request = new DefaultFullHttpRequest(..);        pool.sendMsg(address,request);    }}

代码有些未完善，需要自己完善一哈，本文主要是做下学习记录