2、netty第一个例子，简单的http服务器

用netty来启动一个简单的可处理http请求的服务器。

依照前面写的使用netty的过程。贴上代码

server

 1 import io.netty.bootstrap.ServerBootstrap;
 2 import io.netty.channel.ChannelFuture;
 3 import io.netty.channel.EventLoopGroup;
 4 import io.netty.channel.nio.NioEventLoopGroup;
 5 import io.netty.channel.socket.nio.NioServerSocketChannel;
 6 
 7 /**
 8   * @ClassName:      TestServe
 9   * @Description:     描述  主要作用是写一个可以支持 http 请求的伪服务器。可以看到请求的头和数据 ，也可以自己构建response
10   * @CreateDate:     2019/7/3 23:08
11   * @Version:        1.0
12  */
13 public class TestServer {
14 
15     public static void main(String[] args) throws InterruptedException {
16         EventLoopGroup bossGroup  = new NioEventLoopGroup();//线程，用来接收  事件循环组  死循环
17         EventLoopGroup workerGroup = new NioEventLoopGroup();//线程，用来处理  事件循环组  死循环
18 
19         try{
20             //启动器
21             ServerBootstrap serverBootstrap = new ServerBootstrap();
22             serverBootstrap.group(bossGroup, workerGroup)//添加设置两个线程组
23                     .channel(NioServerSocketChannel.class)
24                     .childHandler(new TestSereverInitlalizer());//这里去设置初始化类
25 
26             ChannelFuture channelFuture = serverBootstrap.bind(8899).sync();//阻塞，等待
27 
28             channelFuture.channel().closeFuture().sync();
29         }finally {
30             bossGroup.shutdownGracefully();//优雅关闭
31             workerGroup.shutdownGracefully();
32         }
33 
34     }
35 }

Initlalizer

 1 import io.netty.channel.ChannelInitializer;
 2 import io.netty.channel.ChannelPipeline;
 3 import io.netty.channel.socket.SocketChannel;
 4 import io.netty.handler.codec.http.HttpServerCodec;
 5 
 6 public class TestSereverInitlalizer extends ChannelInitializer {
 7 
 8     @Override
 9     protected void initChannel(SocketChannel ch) throws Exception {
10         ChannelPipeline pipeline = ch.pipeline();
11 
12         pipeline.addLast("httpServerCodec",new HttpServerCodec());//http里用的
13         pipeline.addLast("testHttpSereverHandle", new TestHttpServerHandler());//把前面设置的handler加到最后
14 
15     }
16 }

Handler

 1 import io.netty.buffer.ByteBuf;
 2 import io.netty.buffer.Unpooled;
 3 import io.netty.channel.ChannelHandlerContext;
 4 import io.netty.channel.SimpleChannelInboundHandler;
 5 import io.netty.handler.codec.http.*;
 6 import io.netty.util.CharsetUtil;
 7 
 8 import java.net.URI;
 9 import java.net.URL;
10 
11 public class TestHttpServerHandler extends SimpleChannelInboundHandler {
12 
13     @Override
14     protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception {
15 
16         System.out.println(msg.getClass());
17 
18         System.out.println(ctx.channel().remoteAddress());
19 
20         if(msg instanceof HttpRequest) {//如果没加这个，用curl访问时，会报错，用浏览器访问不会报错
21 //            System.out.println("执行了！！！！！");
22 
23             HttpRequest httpRequest = (HttpRequest) msg;
24 
25             System.out.println("请求方法名" + httpRequest.getMethod().name());
26 
27             URI uri = new URI(httpRequest.uri());
28             if("/favicon.ico".equals(uri.getPath())) {
29                 System.out.println("请求 favicon.ico");
30                 return;
31             }
32 
33             //向客户端返回的内容
34             ByteBuf content = Unpooled.copiedBuffer("Hello world", CharsetUtil.UTF_8);
35             //构建response
36             FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1,HttpResponseStatus.OK,content);
37             response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain");
38             response.headers().set(HttpHeaderNames.CONTENT_LENGTH, content.readableBytes());
39 
40             ctx.writeAndFlush(response);
41             ctx.channel().close();
42         }
43 
44     }
45 
46     @Override
47     public void channelActive(ChannelHandlerContext ctx) throws Exception {
48         System.out.println("channel active");
49         super.channelActive(ctx);
50     }
51 
52     @Override
53     public void channelInactive(ChannelHandlerContext ctx) throws Exception {
54         System.out.println("channel inactive");
55         super.channelInactive(ctx);
56     }
57 
58     @Override
59     public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
60         System.out.println("channel registered");
61         super.channelRegistered(ctx);
62     }
63 
64     @Override
65     public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {
66         System.out.println("channel unregistered");
67         super.channelUnregistered(ctx);
68     }
69 
70     @Override
71     public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
72         System.out.println("handler added");
73         super.handlerAdded(ctx);
74     }
75 }