架构师养成记--21.netty编码解码

背景

作为网络传输框架，免不了哟啊传输对象，对象在传输之前就要序列化，这个序列化的过程就是编码过程。接收到编码后的数据就需要解码，还原传输的数据。

代码

工厂类

 import io.netty.handler.codec.marshalling.DefaultMarshallerProvider;
 import io.netty.handler.codec.marshalling.DefaultUnmarshallerProvider;
 import io.netty.handler.codec.marshalling.MarshallerProvider;
 import io.netty.handler.codec.marshalling.MarshallingDecoder;
 import io.netty.handler.codec.marshalling.MarshallingEncoder;
 import io.netty.handler.codec.marshalling.UnmarshallerProvider;

 import org.jboss.marshalling.MarshallerFactory;
 import org.jboss.marshalling.Marshalling;
 import org.jboss.marshalling.MarshallingConfiguration;

 /**
  * Marshalling工厂
  * @author（alienware）
  * @since 2014-12-16
  */
 public final class MarshallingCodeCFactory {

     /**
      * 创建Jboss Marshalling解码器MarshallingDecoder
      * @return MarshallingDecoder
      */
     public static MarshallingDecoder buildMarshallingDecoder() {
         //首先通过Marshalling工具类的精通方法获取Marshalling实例对象 参数serial标识创建的是java序列化工厂对象。
         final MarshallerFactory marshallerFactory = Marshalling.getProvidedMarshallerFactory("serial");
         //创建了MarshallingConfiguration对象，配置了版本号为5
         final MarshallingConfiguration configuration = new MarshallingConfiguration();
         configuration.setVersion(5);
         //根据marshallerFactory和configuration创建provider
         UnmarshallerProvider provider = new DefaultUnmarshallerProvider(marshallerFactory, configuration);
         //构建Netty的MarshallingDecoder对象，俩个参数分别为provider和单个消息序列化后的最大长度
         MarshallingDecoder decoder = new MarshallingDecoder(provider, 1024 * 1024 * 1);
         return decoder;
     }

     /**
      * 创建Jboss Marshalling编码器MarshallingEncoder
      * @return MarshallingEncoder
      */
     public static MarshallingEncoder buildMarshallingEncoder() {
         final MarshallerFactory marshallerFactory = Marshalling.getProvidedMarshallerFactory("serial");
         final MarshallingConfiguration configuration = new MarshallingConfiguration();
         configuration.setVersion(5);
         MarshallerProvider provider = new DefaultMarshallerProvider(marshallerFactory, configuration);
         //构建Netty的MarshallingEncoder对象，MarshallingEncoder用于实现序列化接口的POJO对象序列化为二进制数组
         MarshallingEncoder encoder = new MarshallingEncoder(provider);
         return encoder;
     }
 }

服务器端

 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.logging.LogLevel;
 import io.netty.handler.logging.LoggingHandler;

 public class Server {

     public static void main(String[] args) throws Exception{

         EventLoopGroup pGroup = new NioEventLoopGroup();
         EventLoopGroup cGroup = new NioEventLoopGroup();

         ServerBootstrap b = new ServerBootstrap();
         b.group(pGroup, cGroup)
          .channel(NioServerSocketChannel.class)
          .option(ChannelOption.SO_BACKLOG, 1024)
          //设置日志
          .handler(new LoggingHandler(LogLevel.INFO))
          .childHandler(new ChannelInitializer<SocketChannel>() {
             protected void initChannel(SocketChannel sc) throws Exception {
                 sc.pipeline().addLast(MarshallingCodeCFactory.buildMarshallingDecoder());
                 sc.pipeline().addLast(MarshallingCodeCFactory.buildMarshallingEncoder());
                 sc.pipeline().addLast(new ServerHandler());
             }
         });

         ChannelFuture cf = b.bind(8765).sync();

         cf.channel().closeFuture().sync();
         pGroup.shutdownGracefully();
         cGroup.shutdownGracefully();

     }
 }

 import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;

 import java.io.File;
 import java.io.FileOutputStream;

 import bhz.utils.GzipUtils;

 public class ServerHandler extends ChannelHandlerAdapter{

     @Override
     public void channelActive(ChannelHandlerContext ctx) throws Exception {

     }

     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
         Req req = (Req)msg;
         System.out.println("Server : " + req.getId() + ", " + req.getName() + ", " + req.getRequestMessage());
         byte[] attachment = GzipUtils.ungzip(req.getAttachment());

         String path = System.getProperty("user.dir") + File.separatorChar + "receive" +  File.separatorChar + "001.jpg";
         FileOutputStream fos = new FileOutputStream(path);
         fos.write(attachment);
         fos.close();

         Resp resp = new Resp();
         resp.setId(req.getId());
         resp.setName("resp" + req.getId());
         resp.setResponseMessage("响应内容" + req.getId());
         ctx.writeAndFlush(resp);//.addListener(ChannelFutureListener.CLOSE);
     }

     @Override
     public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {

     }

     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
         ctx.close();
     }

 }

客户端

 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.SocketChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;

 import java.io.File;
 import java.io.FileInputStream;

 import bhz.utils.GzipUtils;

 public class Client {

     public static void main(String[] args) throws Exception{

         EventLoopGroup group = new NioEventLoopGroup();
         Bootstrap b = new Bootstrap();
         b.group(group)
          .channel(NioSocketChannel.class)
          .handler(new ChannelInitializer<SocketChannel>() {
             @Override
             protected void initChannel(SocketChannel sc) throws Exception {
                 sc.pipeline().addLast(MarshallingCodeCFactory.buildMarshallingDecoder());
                 sc.pipeline().addLast(MarshallingCodeCFactory.buildMarshallingEncoder());
                 sc.pipeline().addLast(new ClientHandler());
             }
         });

         ChannelFuture cf = b.connect("127.0.0.1", 8765).sync();

         for(int i = 0; i < 5; i++ ){
             Req req = new Req();
             req.setId("" + i);
             req.setName("pro" + i);
             req.setRequestMessage("数据信息" + i);
             String path = System.getProperty("user.dir") + File.separatorChar + "sources" +  File.separatorChar + "001.jpg";
             File file = new File(path);
             FileInputStream in = new FileInputStream(file);
             byte[] data = new byte[in.available()];
             in.read(data);
             in.close();
             req.setAttachment(GzipUtils.gzip(data));
             cf.channel().writeAndFlush(req);
         }

         cf.channel().closeFuture().sync();
         group.shutdownGracefully();
     }
 }

 import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.util.ReferenceCountUtil;

 public class ClientHandler extends ChannelHandlerAdapter{

     @Override
     public void channelActive(ChannelHandlerContext ctx) throws Exception {

     }

     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
         try {
             Resp resp = (Resp)msg;
             System.out.println("Client : " + resp.getId() + ", " + resp.getName() + ", " + resp.getResponseMessage());
         } finally {
             ReferenceCountUtil.release(msg);
         }
     }

     @Override
     public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {

     }

     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
         ctx.close();
     }

 }

工具类（压缩文件）

 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.util.zip.GZIPInputStream;
 import java.util.zip.GZIPOutputStream;

 public class GzipUtils {

     public static byte[] gzip(byte[] data) throws Exception{
         ByteArrayOutputStream bos = new ByteArrayOutputStream();
         GZIPOutputStream gzip = new GZIPOutputStream(bos);
         gzip.write(data);
         gzip.finish();
         gzip.close();
         byte[] ret = bos.toByteArray();
         bos.close();
         return ret;
     }

     public static byte[] ungzip(byte[] data) throws Exception{
         ByteArrayInputStream bis = new ByteArrayInputStream(data);
         GZIPInputStream gzip = new GZIPInputStream(bis);
         byte[] buf = new byte[1024];
         int num = -1;
         ByteArrayOutputStream bos = new ByteArrayOutputStream();
         while((num = gzip.read(buf, 0 , buf.length)) != -1 ){
             bos.write(buf, 0, num);
         }
         gzip.close();
         bis.close();
         byte[] ret = bos.toByteArray();
         bos.flush();
         bos.close();
         return ret;
     }

     public static void main(String[] args) throws Exception{

         //读取文件
         String readPath = System.getProperty("user.dir") + File.separatorChar + "sources" +  File.separatorChar + "006.jpg";
         File file = new File(readPath);
         FileInputStream in = new FileInputStream(file);
         byte[] data = new byte[in.available()];
         in.read(data);
         in.close();  

         System.out.println("文件原始大小:" + data.length);
         //测试压缩

         byte[] ret1 = GzipUtils.gzip(data);
         System.out.println("压缩之后大小:" + ret1.length);

         byte[] ret2 = GzipUtils.ungzip(ret1);
         System.out.println("还原之后大小:" + ret2.length);

         //写出文件
         String writePath = System.getProperty("user.dir") + File.separatorChar + "receive" +  File.separatorChar + "006.jpg";
         FileOutputStream fos = new FileOutputStream(writePath);
         fos.write(ret2);
         fos.close();        

     }

 }

数据对象

 import java.io.Serializable;

 public class Req implements Serializable{

     private static final long  SerialVersionUID = 1L;

     private String id ;
     private String name ;
     private String requestMessage ;
     private byte[] attachment;

     public String getId() {
         return id;
     }
     public void setId(String id) {
         this.id = id;
     }
     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public String getRequestMessage() {
         return requestMessage;
     }
     public void setRequestMessage(String requestMessage) {
         this.requestMessage = requestMessage;
     }
     public byte[] getAttachment() {
         return attachment;
     }
     public void setAttachment(byte[] attachment) {
         this.attachment = attachment;
     }

 }

 import java.io.Serializable;

 public class Resp implements Serializable{

     private static final long serialVersionUID = 1L;

     private String id;
     private String name;
     private String responseMessage;

     public String getId() {
         return id;
     }
     public void setId(String id) {
         this.id = id;
     }
     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public String getResponseMessage() {
         return responseMessage;
     }
     public void setResponseMessage(String responseMessage) {
         this.responseMessage = responseMessage;
     }

 }