我的Netty笔记

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.shinho</groupId>
  <artifactId>kylinstore</artifactId>
  <packaging>jar</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>kylinstore</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <jackson.version>2.5.0</jackson.version>
    <!-- log4j日志文件管理包版本 -->
    <slf4j.version>1.7.7</slf4j.version>
    <log4j.version>1.2.17</log4j.version>
  </properties>

  <dependencies>
    <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
       <version>4.12</version>
       <scope>test</scope>
    </dependency>
    <!-- 导入java ee jar 包 -->
    <dependency>
        <groupId>javax</groupId>
        <artifactId>javaee-api</artifactId>
        <version>7.0</version>
    </dependency>

    <!-- json -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>1.2.3</version>
    </dependency>

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>${jackson.version}</version>
    </dependency>

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>${jackson.version}</version>
    </dependency>

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>${jackson.version}</version>
    </dependency>
    <!-- 日志文件管理包 -->
    <!-- log start -->
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>${log4j.version}</version>
    </dependency>
    <!-- 格式化对象，方便输出日志 --> 

    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>${slf4j.version}</version>
    </dependency>  

    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>${slf4j.version}</version>
    </dependency>
    <!-- log end --> 

    <dependency>
          <groupId>org.freemarker</groupId>
          <artifactId>freemarker</artifactId>
          <version>2.3.27-incubating</version>
    </dependency>

    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>0.2.9</version>
    </dependency>

    <dependency>
      <groupId>org.ehcache</groupId>
      <artifactId>ehcache</artifactId>
      <version>3.4.0</version>
    </dependency>
    <dependency>
        <groupId>jaxen</groupId>
        <artifactId>jaxen</artifactId>
        <version>1.1.6</version>
    </dependency>
    <dependency>
        <groupId>io.netty</groupId>
        <artifactId>netty-all</artifactId> <!-- Use 'netty-all' for 4.0 or above -->
        <version>4.1.23.Final</version>
        <scope>compile</scope>
    </dependency>
  </dependencies>
  <build>
    <finalName>dsp</finalName>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
  </build>
</project>

入口文件

package com.shinho.kylinstore;

import javax.xml.ws.spi.http.HttpHandler;

import io.netty.bootstrap.*;
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 io.netty.handler.stream.ChunkedWriteHandler;

import com.shinho.kylinstore.http.*;

public class HttpServer {

    public static void main(String[] args) throws Exception {
        int port = 8083;
        new HttpServer().run(port);
    }

    public void run(final int port) 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 {

                            // HTTP请求消息解码器
                            ch.pipeline().addLast("http-decoder", new HttpRequestDecoder());

                            /*
                             * HttpObjectAggregator解码器
                             * 将多个消息转换为单一的FullHttpRequest或FullHttpResponse对象
                             */
                            ch.pipeline().addLast("http-aggregator", new HttpObjectAggregator(65536));

                            //HTTP响应编码器,对HTTP响应进行编码
                            ch.pipeline().addLast("http-encoder", new HttpResponseEncoder());

                            //ChunkedWriteHandler的主要作用是支持异步发送大的码流,但不占用过多的内存,防止JAVA内存溢出
                            ch.pipeline().addLast("http-chunked",
                                    new ChunkedWriteHandler());

                            ch.pipeline().addLast("httpServerHandler", new HttpServerHandler());
                        }
                    });
            ChannelFuture future = b.bind("localhost", port).sync();
            System.out.println("HTTP Server startup.");
            future.channel().closeFuture().sync();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}

请求处理文件

package com.shinho.kylinstore.http;

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.DecoderResult;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.DefaultHttpResponse;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.HttpHeaderNames;
import io.netty.handler.codec.http.HttpMethod;
import io.netty.handler.codec.http.HttpResponse;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.HttpVersion;
import io.netty.util.CharsetUtil;

public class HttpServerHandler extends SimpleChannelInboundHandler<FullHttpRequest> {

    @Override
    protected void channelRead0(ChannelHandlerContext context, FullHttpRequest request) throws Exception {
        //
        if (!request.decoderResult().isSuccess()) {
            sendError(context, HttpResponseStatus.BAD_REQUEST);
            return;
        }

        //
        if (request.method() != HttpMethod.GET) {
            sendError(context, HttpResponseStatus.METHOD_NOT_ALLOWED);
            return;
        }

        FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
        response.content().writeInt(100);
        context.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
            throws Exception {
        cause.printStackTrace();
        if (ctx.channel().isActive()) {
            sendError(ctx, HttpResponseStatus.INTERNAL_SERVER_ERROR);
        }
    }

    private static void sendError(ChannelHandlerContext ctx,
                                  HttpResponseStatus status) {
        DefaultFullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1,status,
                Unpooled.copiedBuffer("Failure: " + status.toString()+ "\r\n", CharsetUtil.UTF_8));
        response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain; charset=UTF-8");
        ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
    }
}