netty(二)——对象传递-优快云博客

本文链接：https://blog.youkuaiyun.com/iteye_15162/article/details/82582247

本文介绍了如何使用Netty框架在服务器和客户端之间传递实现了Serializable接口的自定义对象，包括服务器端代码、客户端代码及核心流程解析。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

上一篇中服务端把字符串转换成字符数组后传给客户端，那么能否直接传递对象呢？答案当然是可以，不过这个对象必须实现了Serializable接口（如果对象没实现Serializable接口，那么将不能传递该对象，但是程序也没有报以错，具体还得查看netty源码怎么写的）。

要传递的对象：

public class User implements Serializable {

    private Long id;
    private String username;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                '}';
    }
}

服务器端代码：

public class ObjectServer {

    public void run() throws InterruptedException {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) throws Exception {
                            ch.pipeline().addLast(new ObjectDecoder(ClassResolvers.cacheDisabled(this.getClass().getClassLoader())),new ObjectEncoder(), new ObjectServerHandler());
                        }
                    })
                    .option(ChannelOption.SO_BACKLOG, 128)
                    .childOption(ChannelOption.SO_KEEPALIVE, true);
            ChannelFuture f = b.bind(7777).sync();
            System.out.println("server started.");
            f.channel().closeFuture().sync();
        } finally {
            workerGroup.shutdownGracefully();
            bossGroup.shutdownGracefully();
        }
    }

    public static void main(String[] args) throws Exception {
        new ObjectServer().run();
    }
}

public class ObjectServerHandler extends ChannelInboundHandlerAdapter {

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        User user = (User) msg;
        System.out.println(user);
        user.setUsername("ooxx");
        ctx.write(user);
        ctx.flush();
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.close();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        //打印异常信息并关闭连接
        cause.printStackTrace();
        ctx.close();
    }
}

客户端代码：

public class ObjectClient {

    public static void main(String[] args) throws InterruptedException {
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap();
            b.group(workerGroup)
                    .channel(NioSocketChannel.class)
                    .option(ChannelOption.SO_KEEPALIVE, true)
                    .handler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) throws Exception {
                            ch.pipeline().addLast(new ObjectDecoder(ClassResolvers.cacheDisabled(this.getClass().getClassLoader())),new ObjectEncoder(), new ObjectClientHandler());
                        }
                    });
            ChannelFuture f = b.connect("127.0.0.1", 7777).sync();
            f.channel().closeFuture().sync();
        } finally {
            workerGroup.shutdownGracefully();
        }
    }
}

public class ObjectClientHandler extends ChannelInboundHandlerAdapter {

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        User user = new User();
        user.setId(1L);
        user.setUsername("netty");
        ctx.write(user);
        ctx.flush();
        System.out.println("xxx");
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        User user = (User) msg;
        System.out.println(user);
        ctx.close();
    }

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

原文：http://www.nexusy.com/2014/06/11/netty-2/