基于netty构建http服务器

深藏阁楼爱情的钟 2022-12-23 09:59 176阅读 0赞

# 基于netty构建http服务器 #

基于Netty构建Http服务的流程如下：

1.  Client向Server发送http请求。
2.  Server端对http请求进行解析。
3.  Server端向Client发送http响应。
4.  Client对http响应进行解析。

流程图如下：

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMjI4MTI4NDk_size_16_color_FFFFFF_t_70_pic_center]

## 服务器端实现 ##

package com.morris.netty.protocol.http;
    
    import io.netty.bootstrap.ServerBootstrap;
    import io.netty.buffer.ByteBuf;
    import io.netty.buffer.Unpooled;
    import io.netty.channel.*;
    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.*;
    import io.netty.util.CharsetUtil;
    import lombok.extern.slf4j.Slf4j;
    
    import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
    import static io.netty.handler.codec.http.HttpResponseStatus.OK;
    import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
    
    @Slf4j
    public class Server { 
    
        private static final int port = 8899;
    
        public static void main(String[] args) throws Exception { 
            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 HttpRequestDecoder()); // 请求消息解码器
                                ch.pipeline().addLast(new HttpObjectAggregator(65536));// 目的是将多个消息转换为单一的request或者response对象
                                ch.pipeline().addLast(new HttpResponseEncoder());//响应编码器
                                ch.pipeline().addLast(new ChannelInboundHandlerAdapter() { 
                                    @Override
                                    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { 
                                        FullHttpRequest request = (FullHttpRequest) msg;
                                        log.info("method：{}", request.method().name());
                                        log.info("uri：{}", request.uri());
                                        log.info("content：{}", request.content().toString(CharsetUtil.UTF_8));
    
                                        FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, OK);
                                        response.headers().set(CONTENT_TYPE, "text/html; charset=UTF-8");
                                        ByteBuf buffer = Unpooled.copiedBuffer("<h3>hello world</h3>", CharsetUtil.UTF_8);
                                        response.content().writeBytes(buffer);
                                        buffer.release();
                                        request.release();
                                        ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
                                    }
                                });// 业务逻辑
                            }
                        });
                ChannelFuture future = b.bind("127.0.0.1", port).sync();
                log.info("HTTP服务器启动，网址是 : " + "http://127.0.0.1:" + port);
                future.channel().closeFuture().sync();
            } finally { 
                bossGroup.shutdownGracefully();
                workerGroup.shutdownGracefully();
            }
        }
    }

在浏览器输入`http://127.0.0.1:8899`就可以看到页面显示`hello world`。

## 客户端实现 ##

package com.morris.netty.protocol.http;
    
    import io.netty.bootstrap.Bootstrap;
    import io.netty.channel.*;
    import io.netty.channel.nio.NioEventLoopGroup;
    import io.netty.channel.socket.nio.NioSocketChannel;
    import io.netty.handler.codec.http.*;
    import io.netty.util.CharsetUtil;
    import lombok.extern.slf4j.Slf4j;
    
    @Slf4j
    public class Client { 
    
        public static void main(String[] args) throws InterruptedException { 
    
            EventLoopGroup workerGroup = new NioEventLoopGroup();
            try { 
                Bootstrap b = new Bootstrap();
                b.group(workerGroup)
                        .channel(NioSocketChannel.class)
                        .handler(new ChannelInitializer() { 
    
                            @Override
                            protected void initChannel(Channel ch) throws Exception { 
                                ch.pipeline().addLast(new HttpResponseDecoder()); // 响应解码器
                                ch.pipeline().addLast(new HttpObjectAggregator(65536));
                                ch.pipeline().addLast(new HttpRequestEncoder()); // 请求编码器
                                ch.pipeline().addLast(new ChannelInboundHandlerAdapter() { 
    
                                    @Override
                                    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { 
                                        FullHttpResponse httpResponse = (FullHttpResponse)msg;
                                        log.info("status:{}", httpResponse.status());
                                        log.info("headers:{}", httpResponse.headers());
                                        log.info("body:{}", httpResponse.content().toString(CharsetUtil.UTF_8));
                                        httpResponse.release();
                                    }
    
                                    @Override
                                    public void channelActive(ChannelHandlerContext ctx) throws Exception { 
                                        DefaultFullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/");
    
                                        // 构建http请求
                                        request.headers().set(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE);
                                        request.headers().set(HttpHeaderNames.CONTENT_LENGTH, request.content().readableBytes());
                                        // 发送http请求
                                        ctx.writeAndFlush(request);
                                    }
                                });
                            }
                        });
    
                // 启动 server.
                ChannelFuture f = b.connect("127.0.0.1", 8899).sync();
    
                // 等待socket关闭
                f.channel().closeFuture().sync();
            } finally { 
                workerGroup.shutdownGracefully();
            }
        }
    }

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMjI4MTI4NDk_size_16_color_FFFFFF_t_70_pic_center]: /images/20221120/4de17ad19a6444158b68a021176a39cf.png