Question

**chatclient.java**
 package com.examplechat;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.sctp.nio.NioSctpChannel;
public class ChatClient {   
    public static void main(String[] args) throws InterruptedException, IOException  {
      new ChatClient("localhost", 8000).run();
    }   
    private final String host;
    private final int port;

    public ChatClient(String host, int port) {
        super();
        this.host = host;
        this.port = port;
    }
    public void run() throws InterruptedException, IOException {
  EventLoopGroup group = new NioEventLoopGroup();  
  try {
      Bootstrap bootstrap = new Bootstrap()
              .group(group)
              .channel(NioSctpChannel.class)
              .handler(new ChatClientInitilizer());       
      Channel channel = bootstrap.connect(host, port).sync().channel(); 
      BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
     while(true) {
         channel.write(in.readLine()+ "\r\n");
          }     
    }
  finally {
    group.shutdownGracefully();  } 
  } 
    }
**ChatServer.java**
package com.examplechat;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
public class ChatServer {
public static void main(String[] args) throws InterruptedException  {
        new ChatServer(8000).run();
    }
    private final int port;
    public ChatServer(int port) {
        super();
        this.port = port;
    }
    public void run() throws InterruptedException  {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap bootstrap = new ServerBootstrap()
            .group(bossGroup, workerGroup)
            .channel(NioServerSocketChannel.class)
            .childHandler(new ChatServerInitializer());
        bootstrap.bind(port).sync().channel().closeFuture().sync();
        }
        finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }       
    }}

我正在尝试使用netty创建聊天应用程序。当我尝试运行聊天客户端时，我启动了chatserver java应用程序。它显示

线程“main”中的异常io.netty.channel.ChannelException：无法使用从类类创建Channel io.netty.channel.sctp.nio.NioSctpChannel at io.netty.channel.ReflectiveChannelFactory.newChannel （ReflectiveChannelFactory.java:40）

我甚至更改了pom.xml上的依赖项，但每次运行时我都收到同样的错误

更新 错误-1： Unable to create Channel error已被我自己清除

我自己已经回答了，请帮我解决第二个问题

错误-2 ：我收到一个名为警告的新错误：Failed to initialize a channel. Closing: [id: 0x9e4e05e0] java.lang.ClassCastException: io.netty.channel.sctp.nio.NioSctpChannel cannot be cast to io.netty.channel.socket.SocketChannel

如果您需要https://github.com/cyborgsri/Chat-Application/tree/master/netty-chat-youtube/src/main/java/com/examplechat，这是github链接。

Answer 1

我收到了错误

Unable to create Channel from class class io.netty.channel 是由引起：java.lang.UnsupportedOperationException： ibsctp.so.1：无法打开共享对象文件：没有这样的文件或 directory`

我通过以下方式安装lksctp-tools后清除了此错误：

sudo apt-get install lksctp-tools

现在频道已注册。但是我收到了一个新的错误 警告：

Failed to initialize a channel. Closing: [id: 0x9e4e05e0] java.lang.ClassCastException: io.netty.channel.sctp.nio.NioSctpChannel cannot be cast to io.netty.channel.socket.SocketChannel

Answer 2

发生错误是因为您使用：

public class ChatServerInitializer extends ChannelInitializer<SocketChannel>

将其更改为：

public class ChatServerInitializer extends ChannelInitializer<Channel>

无法从类io.netty.channel.sctp.nio.NioSctpChannel创建Channel

2 个答案: