建网站需要哪些,化工企业常用推广网站,免费seo课程,哪个网站可以做验证码兼职之前我们介绍了用特殊分隔符来分割每个报文#xff0c;但是如果传输的数据中恰好有个特殊分隔符#xff0c;它将会被拆分成多个#xff0c;于是#xff0c;为了进一步避免这个问题#xff0c;还有一种解决方案是在两端的channelPipeline中用一个固定长度来区分#xff0c…之前我们介绍了用特殊分隔符来分割每个报文但是如果传输的数据中恰好有个特殊分隔符它将会被拆分成多个于是为了进一步避免这个问题还有一种解决方案是在两端的channelPipeline中用一个固定长度来区分这样也可以解决粘包半包的问题
1.Server
package splicing.fixed;import constant.Constant;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
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.nio.NioServerSocketChannel;
import io.netty.handler.codec.FixedLengthFrameDecoder;import java.net.InetSocketAddress;public class FixedLengthEchoServer {public static final String RESPONSE Welcome to Netty;public static void main(String[] args) throws InterruptedException {FixedLengthEchoServer fixedLengthEchoServer new FixedLengthEchoServer();System.out.println(服务器即将启动);fixedLengthEchoServer.start();}public void start() throws InterruptedException {FixedLengthServerHandler serverHandler new FixedLengthServerHandler();EventLoopGroup group new NioEventLoopGroup();// 线程组try {// 服务端启动必须ServerBootstrap b new ServerBootstrap();b.group(group)// 将线程组传入.channel(NioServerSocketChannel.class) // 指定使用NIO进行网络传输.localAddress(new InetSocketAddress(Constant.DEFAULT_PORT)) // 指定服务器监听端口// 服务端每接收到一个连接请求就会新启一个Socket通信也就是channel// 所以下面这段代码的作用就是为这个子channel增加handler.childHandler(new ChannelInitializerImp());// 异步绑定到服务器,sync()会阻塞直到完成ChannelFuture f b.bind().sync();System.out.println(服务器启动完成,等待客户端的连接和数据.....);// 阻塞直到服务器的channel关闭f.channel().closeFuture().sync();} finally {group.shutdownGracefully().sync();}}private static class ChannelInitializerImp extends ChannelInitializerChannel {Overrideprotected void initChannel(Channel ch) throws Exception {ch.pipeline().addLast(new FixedLengthFrameDecoder(FixedLengthEchoClient.REQUEST.length()));ch.pipeline().addLast(new FixedLengthServerHandler());}}
}
package splicing.fixed;import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;import java.util.concurrent.atomic.AtomicInteger;public class FixedLengthServerHandler extends ChannelInboundHandlerAdapter {private AtomicInteger counter new AtomicInteger(0);Overridepublic void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {ByteBuf in (ByteBuf) msg;String request in.toString(CharsetUtil.UTF_8);System.out.println(Server Accept[ request ] and the counter is : counter.incrementAndGet());ctx.writeAndFlush(Unpooled.copiedBuffer(FixedLengthEchoServer.RESPONSE.getBytes()));
// super.channelRead(ctx, msg);}Overridepublic void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {cause.printStackTrace();ctx.close();
// super.exceptionCaught(ctx, cause);}
}
2.Client
package splicing.fixed;import constant.Constant;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
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.nio.NioSocketChannel;
import io.netty.handler.codec.FixedLengthFrameDecoder;import java.net.InetSocketAddress;public class FixedLengthEchoClient {public static final String REQUEST Mark,zhuge,zhouyu,fox,loulan;private final String host;public FixedLengthEchoClient(String host) {this.host host;}public void start() throws InterruptedException {EventLoopGroup group new NioEventLoopGroup();try {// 客户端启动必须Bootstrap b new Bootstrap();b.group(group)// 将线程组传入.channel(NioSocketChannel.class) // 指定使用NIO进行网络传输.remoteAddress(new InetSocketAddress(host, Constant.DEFAULT_PORT)).handler(new ChannelInitializerImp());ChannelFuture f b.connect().sync();System.out.println(已连接到服务器....);f.channel().closeFuture().sync();} finally {group.shutdownGracefully().sync();}}private static class ChannelInitializerImp extends ChannelInitializerChannel {Overrideprotected void initChannel(Channel ch) throws Exception {ch.pipeline().addLast(new FixedLengthFrameDecoder(FixedLengthEchoServer.RESPONSE.length()));ch.pipeline().addLast(new FixedLengthClientHandler());}}public static void main(String[] args) throws InterruptedException {new FixedLengthEchoClient(Constant.DEFAULT_SERVER_IP).start();}
}
package splicing.fixed;import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.util.CharsetUtil;import java.util.concurrent.atomic.AtomicInteger;public class FixedLengthClientHandler extends SimpleChannelInboundHandlerByteBuf {private AtomicInteger counter new AtomicInteger(0);Overrideprotected void channelRead0(ChannelHandlerContext ctx, ByteBuf msg) throws Exception {System.out.println(client Accept [ msg.toString(CharsetUtil.UTF_8) ] and the counter is : counter.incrementAndGet());}Overridepublic void channelActive(ChannelHandlerContext ctx) throws Exception {ByteBuf msg null;for (int i 0; i 100; i) {msg Unpooled.buffer(FixedLengthEchoClient.REQUEST.length());msg.writeBytes(FixedLengthEchoClient.REQUEST.getBytes());ctx.writeAndFlush(msg);}
// super.channelActive(ctx);}Overridepublic void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {cause.printStackTrace();ctx.close();
// super.exceptionCaught(ctx, cause);}
}
3.结果展示 这种方案的限制在于要提前直到客户端和服务端要发送的报文并且这个长度是固定的不能变如果变了还是会产生粘包半包的问题那么有的人可能会想有没有更好的解决方案别着急下一期我们接着分析
