网络编程之每天学习一点点[day13]-----netty编解码技术
发布日期:2021-06-30 13:45:26
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分类:技术文章
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编解码技术,说白了就是java序列化传输,序列化的目的就两个:
第一个是进行网络传输,第二对象持久化。
虽然我们可以使用java进行对象序列化,netty去传输。但是java序列化的硬伤太多,比如java序列话没办法跨语言、序列化后的码流太大、序列化性能太低等等
主流的编解码框架:
JBOSS的MarsShaling包
google的Protobuf
基于Protobuf的Kyro
MessagePack框架
Jboss Marshalling是一个java对象序列化包,对jdk默认的序列化框架进行了优化,但又保留了跟java.io.serlalizable接口的兼容,同时增加了一些可调的参数和附加特性。
类库:jboss-marshalling-1.3.0、jboss-marshalling-serial-1.3.0
我们使用客户端传输的是一个req对象:
import java.io.Serializable;public class Req implements Serializable{ /** * */ private static final long serialVersionUID = 6673744374596339216L; 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; }}
服务器端响应的对象是Resp:
import java.io.Serializable;public class Resp implements Serializable{ /** * */ private static final long serialVersionUID = -3041772672090376328L; 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; } }
客户端和服务端的代码中都增加了marshalling的解码器和编码器
sc.pipeline().addLast(MarshallingCodeCFactory.buildMarshallingDecoder()); sc.pipeline().addLast(MarshallingCodeCFactory.buildMarshallingEncoder());
先看下客户端的代码
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() { @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(); }}
客户端封装了5个req对象,并且读取本地图片001.jpg,使用gzip压缩后传递给服务端。
看下客户端处理器:
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(); } }
附上gzip工具类:
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(); } }
再看下我们的server代码:
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() { 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(); }}
ServerHandler
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(); } }
读取客户端发送的req,将其中的图片放置在receice文件下,封装响应报文给客户端。
看下我们的重点,MarshallingCodeCFactory:
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(jeffSheng) */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; }}
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