Java基於Netty實現Http server的實戰

import io.netty.bootstrap.ServerBootstrap;
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.NioServerSocketChannel;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpRequestDecoder;
import io.netty.handler.codec.http.HttpResponseEncoder;
import lombok.extern.slf4j.Slf4j;
 
/**
 * http server based netty
 *
 * @author summer
 * @version $Id: SimpleHttpServer.java, v 0.1 2022年01月26日 9:34 AM summer Exp $
 */
@Slf4j
public class SimpleHttpServer {
 
    /**
     * host
     */
    private final static String host = "127.0.0.1";
 
    /**
     * 埠號
     */
    private final static Integer port = 8085;
 
    /**
     * netty伺服器端啟動方法
     */
    public void start() {
        log.info("SimpleHttpServer start begin ");
 
        EventLoopGroup bossEventLoopGroup = new NioEventLoopGroup(1);
        EventLoopGroup workerEventLoopGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap()
                    .group(bossEventLoopGroup, workerEventLoopGroup)
                    .channel(NioServerSocketChannel.class)
                    //開啟tcp nagle演演算法
                    .childOption(ChannelOption.TCP_NODELAY, true)
                    //開啟長連線
                    .childOption(ChannelOption.SO_KEEPALIVE, true)
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel c) {
                            c.pipeline().addLast(new HttpRequestDecoder())
                                    .addLast(new HttpResponseEncoder())
                                    .addLast(new HttpObjectAggregator(512 * 1024))
                                    .addLast(new SimpleHttpServerHandler());
 
                        }
                    });
 
            ChannelFuture channelFuture = serverBootstrap.bind(host, port).sync();
 
            log.info("SimpleHttpServer start at port " + port);
 
            channelFuture.channel().closeFuture().sync();
        } catch (Exception e) {
            log.error("SimpleHttpServer start exception,", e);
        } finally {
            log.info("SimpleHttpServer shutdown bossEventLoopGroup&workerEventLoopGroup gracefully");
            bossEventLoopGroup.shutdownGracefully();
            workerEventLoopGroup.shutdownGracefully();
        }
    }
}

import com.alibaba.fastjson.JSON;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.*;
import lombok.extern.slf4j.Slf4j;
 
import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Map;
 
/**
 * http伺服器端處理handler實現
 *
 * @author summer
 * @version $Id: SimpleHttpServerHandler.java, v 0.1 2022年01月26日 9:44 AM summer Exp $
 */
@Slf4j
public class SimpleHttpServerHandler extends SimpleChannelInboundHandler<FullHttpRequest> {
 
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, FullHttpRequest fullHttpRequest) {
        try {
            log.info("SimpleHttpServerHandler receive fullHttpRequest=" + fullHttpRequest);
 
            String result = doHandle(fullHttpRequest);
            log.info("SimpleHttpServerHandler,result=" + result);
            byte[] responseBytes = result.getBytes(StandardCharsets.UTF_8);
 
            FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_0, HttpResponseStatus.OK,
                    Unpooled.wrappedBuffer(responseBytes));
            response.headers().set("Content-Type", "text/html; charset=utf-8");
            response.headers().setInt("Content-Length", response.content().readableBytes());
 
            boolean isKeepAlive = HttpUtil.isKeepAlive(response);
            if (!isKeepAlive) {
                ctx.write(response).addListener(ChannelFutureListener.CLOSE);
            } else {
                response.headers().set("Connection", "keep-alive");
                ctx.write(response);
            }
        } catch (Exception e) {
            log.error("channelRead0 exception,", e);
        }
    }
 
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        cause.printStackTrace();
        ctx.close();
    }
 
    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) {
        ctx.flush();
    }
 
    /**
     * 實際處理
     *
     * @param fullHttpRequest HTTP請求引數
     * @return
     */
    private String doHandle(FullHttpRequest fullHttpRequest) {
        if (HttpMethod.GET == fullHttpRequest.method()) {
            QueryStringDecoder queryStringDecoder = new QueryStringDecoder(fullHttpRequest.uri());
            Map<String, List<String>> params = queryStringDecoder.parameters();
            return JSON.toJSONString(params);
        } else if (HttpMethod.POST == fullHttpRequest.method()) {
            return fullHttpRequest.content().toString();
        }
 
        return "";
    }
}

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
 
@SpringBootApplication
public class SimplehttpserverApplication {
 
    public static void main(String[] args) {
        SimpleHttpServer simpleHttpServer = new SimpleHttpServer();
        simpleHttpServer.start();
 
        SpringApplication.run(SimplehttpserverApplication.class, args);
    }
}