netty框架学习记录

服务器端相关代码：

服务器自定义handle:

客户端相关代码：

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;

import java.net.InetSocketAddress;

public class Client {

    private final int port;
    private final String host;

    public Client(int port, String host) {
        this.port = port;
        this.host = host;
    }

    public void start() throws InterruptedException {
        /*线程组*/
        EventLoopGroup group = new NioEventLoopGroup();
        try{
            /*客户端启动必备*/
            Bootstrap b = new Bootstrap();
            b.group(group)/*把线程组传入*/
                    /*指定使用NIO进行网络传输*/
                    .channel(NioSocketChannel.class)
                    .remoteAddress(new InetSocketAddress(host,port))
                    .handler(new ClientHandle());
            /*连接到远程节点，阻塞直到连接完成*/
            ChannelFuture f = b.connect().sync();
            /*阻塞程序，直到Channel发生了关闭*/
            f.channel().closeFuture().sync();
        }finally {
            group.shutdownGracefully().sync();
        }
    }

    public static void main(String[] args) throws InterruptedException {
        new Client(9999,"127.0.0.1").start();
    }
}


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业务逻辑处理代码：

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.util.CharsetUtil;

public class ClientHandle extends SimpleChannelInboundHandler {

    /*客户端读到数据以后，就会执行*/
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, Object msg){
        // 传统的HTTP接入
        if (msg instanceof FullHttpRequest) {
            handleHttpRequest(ctx, (FullHttpRequest) msg);
        }
        // WebSocket接入
        else if (msg instanceof WebSocketFrame) {
            handleWebSocketFrame(ctx, (WebSocketFrame) msg);
        }
  }

    /*连接建立以后*/
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        ctx.writeAndFlush(Unpooled.copiedBuffer(
                "Hello Netty",CharsetUtil.UTF_8));
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
            throws Exception {
        cause.printStackTrace();
        ctx.close();
    }

    @Override
    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
        super.userEventTriggered(ctx, evt);
    }
    
    private void handleWebSocketFrame(ChannelHandlerContext ctx,
                                      WebSocketFrame frame) {

        //判断是否式打开链路指令


        // 判断是否是关闭链路的指令
        if (frame instanceof CloseWebSocketFrame) {
            handshaker.close(ctx.channel(),
                    (CloseWebSocketFrame) frame.retain());
            return;
        }
        // 判断是否是Ping消息
        if (frame instanceof PingWebSocketFrame) {
            ctx.channel().write(
                    new PongWebSocketFrame(frame.content().retain()));
            return;
        }
        // 本例程仅支持文本消息，不支持二进制消息
        if (!(frame instanceof TextWebSocketFrame)) {
            throw new UnsupportedOperationException(String.format(
                    "%s frame types not supported", frame.getClass().getName()));
        }

        // 返回应答消息
        String _message = ((TextWebSocketFrame) frame).text();

        JSONObject chat = JSON.parseObject(_message);
        String type = chat.get("type").toString();

        if ("login".equals(type)) {
            handleWebSocketLogin(chat, ctx);
        } else if ("logout".equals(type)) {
            handleWebSocketLogout(chat);
        } else if ("message".equals(type)) {
            handleWebSocketMessage(_message);
        }

}


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