netty 基于 protobuf 协议 实现 websocket 版本的简易客服系统

结构

• netty 作为服务端
• protobuf 作为序列化数据的协议
• websocket 前端通讯

演示

GitHub 地址

netty 服务端实现

Server.java 启动类

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;

import java.net.InetSocketAddress;

//websocket长连接示例
public class Server {
    public static void main(String[] args) throws Exception{
        
        // 主线程组
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        // 从线程组
        EventLoopGroup wokerGroup = new NioEventLoopGroup();
        
        try{
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup,wokerGroup)
                    .channel(NioServerSocketChannel.class)
                    .handler(new LoggingHandler(LogLevel.INFO))
                    .childHandler(new ServerChannelInitializer());
            
            ChannelFuture channelFuture = serverBootstrap.bind(new InetSocketAddress(8899)).sync();
            channelFuture.channel().closeFuture().sync();
        }finally {
            bossGroup.shutdownGracefully();
            wokerGroup.shutdownGracefully();
        }
        
    }
}

ServerChannelInitializer.java

import com.example.nettydemo.protobuf.MessageData;
import com.google.protobuf.MessageLite;
import com.google.protobuf.MessageLiteOrBuilder;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.MessageToMessageDecoder;
import io.netty.handler.codec.MessageToMessageEncoder;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpServerCodec;
import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
import io.netty.handler.codec.http.websocketx.extensions.compression.WebSocketServerCompressionHandler;
import io.netty.handler.codec.protobuf.ProtobufDecoder;
import io.netty.handler.stream.ChunkedWriteHandler;

import java.util.List;

import static io.netty.buffer.Unpooled.wrappedBuffer;


public class ServerChannelInitializer extends ChannelInitializer {
    
    @Override
    protected void initChannel(SocketChannel ch) throws Exception {
        ChannelPipeline pipeline = ch.pipeline();
        // HTTP请求的解码和编码
        pipeline.addLast(new HttpServerCodec());
        // 把多个消息转换为一个单一的FullHttpRequest或是FullHttpResponse，
        // 原因是HTTP解码器会在每个HTTP消息中生成多个消息对象HttpRequest/HttpResponse,HttpContent,LastHttpContent
        pipeline.addLast(new HttpObjectAggregator(65536));
        // 主要用于处理大数据流，比如一个1G大小的文件如果你直接传输肯定会撑暴jvm内存的; 增加之后就不用考虑这个问题了
        pipeline.addLast(new ChunkedWriteHandler());
        // WebSocket数据压缩
        pipeline.addLast(new WebSocketServerCompressionHandler());
        // 协议包长度限制
        pipeline.addLast(new WebSocketServerProtocolHandler("/ws", null, true));
        // 协议包解码
        pipeline.addLast(new MessageToMessageDecoder() {
            @Override
            protected void decode(ChannelHandlerContext ctx, WebSocketFrame frame, List