序列化在Netty中的使用

• Java序列化的缺点

1、无法跨语言

　　对于Java序列化后的字节数组，别的语言无法进行反序列化

2、序列化后的码流过大

3、序列化性能低

• 使用JDK自带的序列化进行对象的传输

被传输的，实现了序列化接口的POJO

package org.zln.netty.five.part04.dto;

import org.apache.commons.lang3.builder.ToStringBuilder;

import java.io.Serializable;

/**
 * 用户订购请求信息
 * Created by sherry on 16/11/7.
 */
public class SubscribeReq implements Serializable{

    //序列化
    private static final long serialVersionUID = 1L;

    //订购编号
    private int subReqID;
    //用户名
    private String userName;
    //订购的产品名称
    private String productName;
    //订购者联系电话
    private String phoneName;
    //订购者家庭地址
    private String address;

    @Override
    public String toString() {
        return new ToStringBuilder(this)
                .append("subReqID", subReqID)
                .append("userName", userName)
                .append("productName", productName)
                .append("phoneName", phoneName)
                .append("address", address)
                .toString();
    }

    public int getSubReqID() {
        return subReqID;
    }

    public void setSubReqID(int subReqID) {
        this.subReqID = subReqID;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getProductName() {
        return productName;
    }

    public void setProductName(String productName) {
        this.productName = productName;
    }

    public String getPhoneName() {
        return phoneName;
    }

    public void setPhoneName(String phoneName) {
        this.phoneName = phoneName;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}

package org.zln.netty.five.part04.dto;

import org.apache.commons.lang3.builder.ToStringBuilder;

import java.io.Serializable;

/**
 * 订单请求的响应信息
 * Created by sherry on 16/11/7.
 */
public class SubscribeResp implements Serializable {

    //序列化
    private static final long serialVersionUID = 1L;

    //订购编号
    private int subReqID;
    //订购结果  0-未成功
    private int respCode;
    //可选的详细描述信息
    private String desc;

    @Override
    public String toString() {
        return new ToStringBuilder(this)
                .append("subReqID", subReqID)
                .append("respCode", respCode)
                .append("desc", desc)
                .toString();
    }

    public int getSubReqID() {
        return subReqID;
    }

    public void setSubReqID(int subReqID) {
        this.subReqID = subReqID;
    }

    public int getRespCode() {
        return respCode;
    }

    public void setRespCode(int respCode) {
        this.respCode = respCode;
    }

    public String getDesc() {
        return desc;
    }

    public void setDesc(String desc) {
        this.desc = desc;
    }
}

服务端

package org.zln.netty.five.part04.server;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Created by sherry on 16/11/5.
 */
public class SubReqServer {
    /**
     * 服务端绑定端口号
     */
    private int PORT;

    public SubReqServer(int PORT) {
        this.PORT = PORT;
    }

    /**
     * 日志
     */
    private static Logger logger = LoggerFactory.getLogger(SubReqServer.class);

    public void bind() {
        /*
        NioEventLoopGroup是线程池组
        包含了一组NIO线程,专门用于网络事件的处理
        bossGroup:服务端,接收客户端连接
        workGroup:进行SocketChannel的网络读写
         */
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workGroup = new NioEventLoopGroup();
        try {
            /*
            ServerBootstrap:用于启动NIO服务的辅助类,目的是降低服务端的开发复杂度
             */
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup, workGroup)
                    .channel(NioServerSocketChannel.class)
                    .option(ChannelOption.SO_BACKLOG, 1024)//配置TCP参数,能够设置很多,这里就只设置了backlog=1024,
                    .handler(new LoggingHandler(LogLevel.DEBUG))
                    .childHandler(new SubReqServerInitializer());//绑定I/O事件处理类
            logger.debug("绑定端口号:" + PORT + ",等待同步成功");
            /*
            bind:绑定端口
            sync:同步阻塞方法,等待绑定完成,完成后返回 ChannelFuture ,主要用于通知回调
             */
            ChannelFuture channelFuture = serverBootstrap.bind(PORT).sync();
            logger.debug("等待服务端监听窗口关闭");
            /*
             closeFuture().sync():为了阻塞,服务端链路关闭后才退出.也是一个同步阻塞方法
             */
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            logger.error(e.getMessage(), e);
        } finally {
            logger.debug("优雅退出,释放线程池资源");
            bossGroup.shutdownGracefully();
            workGroup.shutdownGracefully();
        }
    }
}

package org.zln.netty.five.part04.server;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.serialization.ClassResolvers;
import io.netty.handler.codec.serialization.ObjectDecoder;
import io.netty.handler.codec.serialization.ObjectEncoder;

/**
 * Created by sherry on 16/11/5.
 */
public class SubReqServerInitializer extends ChannelInitializer<SocketChannel> {
    @Override
    protected void initChannel(SocketChannel socketChannel) throws Exception {

        ChannelPipeline pipeline = socketChannel.pipeline();

        /*
        ObjectDecoder:对实现了Serializable接口的POJO进行解码,用于解码请求对象
        1024 * 1024:设置1M大小,为最大的单个对象的序列化后的字节长度
        ClassResolvers.weakCachingConcurrentResolver(this.getClass().getClassLoader())):对类加载器进行缓存,线程安全.支持多线程并发访问,当虚拟机内存不足时,释放缓存时的内存,防止内存泄漏
         */
        pipeline.addLast(new ObjectDecoder(1024 * 1024, ClassResolvers.weakCachingConcurrentResolver(this.getClass().getClassLoader())));
        /*
        ObjectEncoder:服务端在发送的时候,将对象进行编码操作
         */
        pipeline.addLast(new ObjectEncoder());
        pipeline.addLast(new SubReqServerHandler());


    }
}

package org.zln.netty.five.part04.server;

import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.zln.netty.five.part03.SessionUtils;
import org.zln.netty.five.part04.dto.SubscribeReq;
import org.zln.netty.five.part04.dto.SubscribeResp;

/**
 * Handler主要用于对网络事件进行读写操作,是真正的业务类
 * 通常只需要关注 channelRead 和 exceptionCaught 方法
 * Created by sherry on 16/11/5.
 */
public class SubReqServerHandler extends ChannelHandlerAdapter {

    /**
     * 日志
     */
    private Logger logger = LoggerFactory.getLogger(SubReqServerHandler.class);

    private static int count = 0;

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        SubscribeReq subscribeReq = (SubscribeReq) msg;
        logger.debug("收到的订单请求信息:
"+subscribeReq);

        //根据请求信息,设置响应信息
        SubscribeResp subscribeResp = getSubscribeResp(subscribeReq);
        ctx.writeAndFlush(subscribeResp);


    }

    private SubscribeResp getSubscribeResp(SubscribeReq subscribeReq) {
        SubscribeResp subscribeResp = new SubscribeResp();
        subscribeResp.setSubReqID(subscribeReq.getSubReqID());
        subscribeResp.setRespCode(subscribeReq.getSubReqID());
        subscribeResp.setDesc("你订购的是一双红皮鞋,三天后发货");
        return subscribeResp;
    }


    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        //将消息发送队列中的消息写入到SocketChannel中发送给对方
        logger.debug("channelReadComplete");
        ctx.flush();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        //发生异常时,关闭 ChannelHandlerContext,释放ChannelHandlerContext 相关的句柄等资源
        logger.error(cause.getMessage(),cause);
        ctx.close();
    }
}

客户端

package org.zln.netty.five.part04.client;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.zln.netty.five.part03.EchoServer;

/**
 * Created by sherry on 16/11/5.
 */
public class SubReqClient {
    /**
     * 日志
     */
    private Logger logger = LoggerFactory.getLogger(EchoServer.class);

    private String HOST;
    private int PORT;

    public SubReqClient(String HOST, int PORT) {
        this.HOST = HOST;
        this.PORT = PORT;
    }

    public void connect(){
        //配置客户端NIO线程组
        EventLoopGroup eventLoopGroup = new NioEventLoopGroup();
        try {
            Bootstrap bootstrap = new Bootstrap();
            bootstrap.group(eventLoopGroup)
                    .channel(NioSocketChannel.class)
                    .option(ChannelOption.TCP_NODELAY,true)
                    .handler(new SubReqClientInitializer());
            //发起异步连接操作
            logger.debug("发起异步连接操作 - start");
            ChannelFuture channelFuture = bootstrap.connect(HOST,PORT).sync();
            logger.debug("发起异步连接操作 - end");
            //等待客户端链路关闭
            logger.debug("等待客户端链路关闭 - start");
            channelFuture.channel().closeFuture().sync();
            logger.debug("等待客户端链路关闭 - end");
        } catch (InterruptedException e) {
            logger.error(e.getMessage(),e);
        }finally {
            //优雅的关闭
            eventLoopGroup.shutdownGracefully();
        }
    }
}

package org.zln.netty.five.part04.client;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.serialization.ClassResolvers;
import io.netty.handler.codec.serialization.ObjectDecoder;
import io.netty.handler.codec.serialization.ObjectEncoder;

/**
 * Created by sherry on 16/11/5.
 */
public class SubReqClientInitializer extends ChannelInitializer<SocketChannel> {
    @Override
    protected void initChannel(SocketChannel socketChannel) throws Exception {

        ChannelPipeline pipeline = socketChannel.pipeline();

        //与服务端不同,这里禁止对类加载器进行缓存
        pipeline.addLast(new ObjectDecoder(1024, ClassResolvers.cacheDisabled(this.getClass().getClassLoader())));
        pipeline.addLast(new ObjectEncoder());
        pipeline.addLast(new SubReqClientHandler());
    }
}

package org.zln.netty.five.part04.client;

import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.zln.netty.five.part04.dto.SubscribeReq;
import org.zln.netty.five.part04.dto.SubscribeResp;

/**
 * Created by sherry on 16/11/5.
 */
public class SubReqClientHandler extends ChannelHandlerAdapter {

    /**
     * 日志
     */
    private Logger logger = LoggerFactory.getLogger(SubReqClientHandler.class);

    private static int count = 0;

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        logger.debug("客户端连接上了服务端");

        for (int i = 0; i < 10; i++) {
            SubscribeReq subscribeReq = getSubscribeReq(i);
            ctx.writeAndFlush(subscribeReq);
        }

    }

    private SubscribeReq getSubscribeReq(int i) {
        SubscribeReq subscribeReq = new SubscribeReq();
        subscribeReq.setSubReqID(i);
        subscribeReq.setUserName("张柳宁"+i);
        subscribeReq.setProductName("红皮鞋"+i);
        subscribeReq.setPhoneName("123"+i);
        subscribeReq.setAddress("地址"+i);
        return subscribeReq;
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        SubscribeResp subscribeResp = (SubscribeResp) msg;
        logger.debug("这是收到的第 " + (++count) + " 笔响应 -- " + subscribeResp);
    }

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

• 使用Marshalling第三方jar进行序列化

POJO不变

工具类

package org.zln.netty.five.part05.marshalling;

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;

public class MarshallingCodeCFactory {
    public static MarshallingDecoder buildMarshallingDecoder() {
        /*
         * 通过 Marshalling 工具类的 getProvidedMarshallerFactory
         * 静态方法获取MarshallerFactory 实例, , 参数 serial 表示创建的是 Java 序列化工厂对象.它是由
         * jboss-marshalling-serial 包提供
         */
        final MarshallerFactory marshallerFactory = Marshalling
                .getProvidedMarshallerFactory("serial");
        /*
         * 创建
         */
        final MarshallingConfiguration configuration = new MarshallingConfiguration();
        configuration.setVersion(5);

        UnmarshallerProvider provider = new DefaultUnmarshallerProvider(
                marshallerFactory, configuration);
        /*
         * provider : 提供商 maxSize : 单个对象最大尺寸
         */
        int maxSize = 1024 << 2;
        MarshallingDecoder decoder = new MarshallingDecoder(provider, maxSize);
        return decoder;
    }

    public static MarshallingEncoder buildMarshallingEncoder() {
        final MarshallerFactory marshallerFactory = Marshalling
                .getProvidedMarshallerFactory("serial");
        final MarshallingConfiguration configuration = new MarshallingConfiguration();
        configuration.setVersion(5);
        MarshallerProvider provider = new DefaultMarshallerProvider(
                marshallerFactory, configuration);
        MarshallingEncoder decoder = new MarshallingEncoder(provider);
        return decoder;
    }

}

服务端

package org.zln.netty.five.part05.server;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import org.zln.netty.five.part05.marshalling.MarshallingCodeCFactory;

/**
 * Created by sherry on 16/11/5.
 */
public class SubReqServerInitializer extends ChannelInitializer<SocketChannel> {
    @Override
    protected void initChannel(SocketChannel socketChannel) throws Exception {

        ChannelPipeline pipeline = socketChannel.pipeline();

        //解码器
        pipeline.addLast(MarshallingCodeCFactory.buildMarshallingDecoder());
        //编码器
        pipeline.addLast(MarshallingCodeCFactory.buildMarshallingEncoder());
        pipeline.addLast(new SubReqServerHandler());


    }
}

客户端

package org.zln.netty.five.part05.client;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import org.zln.netty.five.part05.marshalling.MarshallingCodeCFactory;

/**
 * Created by sherry on 16/11/5.
 */
public class SubReqClientInitializer extends ChannelInitializer<SocketChannel> {
    @Override
    protected void initChannel(SocketChannel socketChannel) throws Exception {

        ChannelPipeline pipeline = socketChannel.pipeline();

        //解码器
        pipeline.addLast(MarshallingCodeCFactory.buildMarshallingDecoder());
        //编码器
        pipeline.addLast(MarshallingCodeCFactory.buildMarshallingEncoder());
        pipeline.addLast(new SubReqClientHandler());
    }
}

其他代码和使用JDK序列化的时候完全一样