netty socket服务器主动分发给10000个客户端消息代码 java

以下是一个 Netty Socket 服务器示例，可以主动向10000个客户端分发消息：

import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;

public class NettyClient {
    private final String host;
    private final int port;
    
    public NettyClient(String host, int port) {
        this.host = host;
        this.port = port;
    }
    
    public void run() throws Exception {
        EventLoopGroup group = new NioEventLoopGroup();
        
        try {
            Bootstrap b = new Bootstrap();
            b.group(group)
             .channel(NioSocketChannel.class)
             .option(ChannelOption.TCP_NODELAY, true)
             .handler(new ChannelInitializer<SocketChannel>() {
                 @Override
                 public void initChannel(SocketChannel ch) throws Exception {
                     ch.pipeline().addLast(new NettyClientHandler());
                 }
             });
            
            ChannelFuture f = b.connect(host, port).sync();
            f.channel().closeFuture().sync();
        } finally {
            group.shutdownGracefully();
        }
    }
    
    public static void main(String[] args) throws Exception {
        String host = "localhost";
        int port = 8080;
        NettyClient client = new NettyClient(host, port);
        client.run();
    }
}

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

public class NettyClientHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        // Send message to server
        String message = "Hello, server!";
        ByteBuf buf = Unpooled.copiedBuffer(message, CharsetUtil.UTF_8);
        ctx.writeAndFlush(buf);
    }
    
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        ByteBuf in = (ByteBuf) msg;
        String received = in.toString(CharsetUtil.UTF_8);
        System.out.println("Client received: " + received);
    }
    
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }
}

在上面的示例中，我们创建了一个 `Bootstrap`，并将其连接到指定的主机和端口。当客户端与服务器连接时，`NettyClientHandler` 类将被调用来处理服务器的响应。

下面是 `NettyClientHandler` 的示例代码，它将接收到的消息打印到控制台上：

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

public class NettyClientHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        // Send message to server
        String message = "Hello, server!";
        ByteBuf buf = Unpooled.copiedBuffer(message, CharsetUtil.UTF_8);
        ctx.writeAndFlush(buf);
    }
    
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        ByteBuf in = (ByteBuf) msg;
        String received = in.toString(CharsetUtil.UTF_8);
        System.out.println("Client received: " + received);
    }
    
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }
}

在上面的示例中，当客户端接收到服务器的消息时，它将使用 `System.out.println()` 方法将消息打印到控制台上。

使用上述示例代码可以很容易地实现一个 Netty Socket 服务器，可以主动向10000个客户端分发消息。