Netty入門之發送序列化對象

Netty發送序列化對象主要在於兩個Handler：

ObjectEncoder：對象編碼器，將輸出Serializable對象編碼爲字節對象ByteBuf，用於寫出對象

ObjectDecoder：對象解碼器，將輸入的ByteBuf字節對象解碼爲Serializable對象，用於讀入對象

 

ObjectEchoClient

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.serialization.ClassResolvers;
import io.netty.handler.codec.serialization.ObjectDecoder;
import io.netty.handler.codec.serialization.ObjectEncoder;
import io.netty.handler.ssl.SslContext;
import io.netty.handler.ssl.SslContextBuilder;
import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
import lombok.extern.slf4j.Slf4j;

/**
 * Java序列化對象客戶端
 */
@Slf4j
public final class ObjectEchoClient {

    static final boolean SSL = System.getProperty("ssl") != null;
    static final String HOST = System.getProperty("host", "127.0.0.1");
    static final int PORT = Integer.parseInt(System.getProperty("port", "8080"));
    static final int SIZE = Integer.parseInt(System.getProperty("size", "15"));

    public static void main(String[] args) throws Exception {

        final SslContext sslCtx;
        if (SSL) {
            sslCtx = SslContextBuilder.forClient().trustManager(InsecureTrustManagerFactory.INSTANCE).build();
        } else {
            sslCtx = null;
        }

        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap();
            b.group(group)
                    .channel(NioSocketChannel.class)
                    .handler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        public void initChannel(SocketChannel ch) throws Exception {
                            ChannelPipeline p = ch.pipeline();
                            if (sslCtx != null) {
                                p.addLast(sslCtx.newHandler(ch.alloc(), HOST, PORT));
                            }
                            p.addLast(
                                    new ObjectEncoder(),//序列化對象編碼器
                                    new ObjectDecoder(ClassResolvers.cacheDisabled(null)),//序列化對象解碼器
                                    new ObjectEchoClientHandler());
                        }
                    });
            log.info("客戶端啓動");
            b.connect(HOST, PORT).sync().channel().closeFuture().sync();
        } finally {
            group.shutdownGracefully();
        }
    }
}

1.在業務Handler之前設置了ObjectEncoder和ObjectDecoder

2.對象解碼Handler可以設置類解析器

 

ObjectEchoClientHandler

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import lombok.extern.slf4j.Slf4j;

import java.util.ArrayList;
import java.util.List;

/**
 * 對象回顯客戶端的處理程序實現。它通過將第一條消息發送到服務器，從而在對象回顯客戶端和服務器之間啓動*乒乓通信。
 */
@Slf4j
public class ObjectEchoClientHandler extends ChannelInboundHandlerAdapter {

    private final List<Integer> firstMessage;

    public ObjectEchoClientHandler() {
        /* 初始化對象，ArrayList爲序列化對象 */
        firstMessage = new ArrayList<Integer>(ObjectEchoClient.SIZE);
        for (int i = 0; i < ObjectEchoClient.SIZE; i ++) {
            firstMessage.add(Integer.valueOf(i));
        }
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) {
        ctx.writeAndFlush(firstMessage);
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg)throws Exception {
        log.info("客戶端收到信息："+msg.toString());
        Thread.sleep(2000L);
        /* 乒乓通信 */
        ctx.write(msg);
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) {
        ctx.flush();
    }

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

1.繼承的類沒有泛型，這裏使用的還是Object對象

2.實現的讀取方法爲channelRead，也是使用Object爲對象

3.服務端也是一樣