Netty（4.0.4）版本压缩/解压字符串消息错误

Question

Netty（4.0.4）版本压缩/解压字符串消息错误

3

我希望在Netty客户端/服务器上应用压缩/解压缩。我在客户端和服务器的管道中使用以下代码：

@Override
protected void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline pipeline = ch.pipeline();
pipeline.addLast("framer", new DelimiterBasedFrameDecoder(
    8192, Delimiters.lineDelimiter()));

pipeline.addLast("decoder", new StringDecoder());
pipeline.addLast("encoder", new StringEncoder());
pipeline.addLast("gzipdeflater", ZlibCodecFactory.newZlibEncoder(ZlibWrapper.GZIP));
pipeline.addLast("gzipinflater", ZlibCodecFactory.newZlibDecoder(ZlibWrapper.GZIP));

// and then business logic.
pipeline.addLast("handler", new NettyClientHandler());        
}

并且服务器为：

@Override
protected void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline pipeline = ch.pipeline();
pipeline.addLast("framer", new DelimiterBasedFrameDecoder(
    8192, Delimiters.lineDelimiter()));
pipeline.addLast("decoder", new StringDecoder());
pipeline.addLast("encoder", new StringEncoder());
pipeline.addLast("gzipdeflater", ZlibCodecFactory.newZlibEncoder(ZlibWrapper.GZIP));
pipeline.addLast("gzipinflater", ZlibCodecFactory.newZlibDecoder(ZlibWrapper.GZIP));
//GlibDecoder
//pipeline.addLast("decoder", new ZlibDecoder());
//pipeline.addLast("encoder", new StringEncoder());
// and then business logic.
pipeline.addLast("handler", new NettyServerHandler());        
}

在启动连接时，客户端报错如下：

警告：初始化通道失败。关闭：[id: 0x3553bb5c] java.lang.NoClassDefFoundError: com/jcraft/jzlib/Inflater at io.netty.handler.codec.compression.JZlibDecoder.(JZlibDecoder.java:28) at io.netty.handler.codec.compression.ZlibCodecFactory.newZlibDecoder(ZlibCodecFactory.java:86) at testChat.NettyClientInitializer.initChannel(NettyClientInitializer.java:36) at testChat.NettyClientInitializer.initChannel(NettyClientInitializer.java:21) at io.netty.channel.ChannelInitializer.channelRegistered(ChannelInitializer.java:70) at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRegistered(DefaultChannelHandlerContext.java:188) at io.netty.channel.DefaultChannelHandlerContext.fireChannelRegistered(DefaultChannelHandlerContext.java:174) at io.netty.channel.DefaultChannelPipeline.fireChannelRegistered(DefaultChannelPipeline.java:730) at io.netty.channel.AbstractChannel$AbstractUnsafe.register0(AbstractChannel.java:426) at io.netty.channel.AbstractChannel$AbstractUnsafe.access$100(AbstractChannel.java:367) at io.netty.channel.AbstractChannel$AbstractUnsafe$1.run(AbstractChannel.java:403) at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:353) at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:366) at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:101) at java.lang.Thread.run(Thread.java:722) 原因是： java.lang.ClassNotFoundException: com.jcraft.jzlib.Inflater at java.net.URLClassLoader$1.run(URLClassLoader.java:366) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:423) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:356) ... 15 more

主程序报错如下：

Exception in thread "main" java.nio.channels.ClosedChannelException

当我尝试在字符串编码之前进行压缩/解压缩时，客户端/服务器可以正常工作，但我仍然遇到了同样的错误？请帮帮我好吗？

- Tareq Saleh

2个回答

0

感谢评论，经过多次尝试，我找到了正确的解决方案： - 在NetBeans中，我将jzlib-1.1.2.jar添加到我的项目中。 - 管道的正确顺序如下代码：

pipeline.addLast("deflater", ZlibCodecFactory.newZlibEncoder(ZlibWrapper.GZIP));
pipeline.addLast("inflater", ZlibCodecFactory.newZlibDecoder(ZlibWrapper.GZIP));

pipeline.addLast("framer", new DelimiterBasedFrameDecoder(
        8192, Delimiters.lineDelimiter()));


pipeline.addLast("decoder", new MyStringDecoder());
pipeline.addLast("encoder", new MyStringEncoder());

在客户端和服务器端都要

- Tareq Saleh

ZlibEncoder不是解压器，而ZlibDecoder才是压缩器吗？因为如果这样的话，你还是搞混了吧？ - Csaba Toth

我遵循这个示例链接，它展示了使用ZlibEncoder进行压缩和使用ZlibDecoder进行解压缩，请自行验证。 - Tareq Saleh

澄清一下，inflate是将数据解压缩并膨胀到其原始大小的操作，因此它是解码器，用于解码先前被deflate压缩过的内容。 - FHannes

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原文链接

- Norman Maurer · Accepted Answer

您需要在pom.xml中添加以下依赖项：

  <dependency>
    <groupId>com.jcraft</groupId>
    <artifactId>jzlib</artifactId>
      <version>1.1.2</version>
  </dependency>

这是因为Netty将所有依赖声明为可选的。