Netty：绑定不匹配

Question

我是 java 新手，正在尝试使用 Netty 构建示例 tcp 服务器。这是我目前拥有的

package http_server;

import java.net.InetSocketAddress;
import java.nio.channels.SocketChannel;

import netty_tutorial.EchoServerHandler;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.ServerSocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;


class server
{
      ServerBootstrap bootstrap;
      int port;

      server(int port_)
      {
          port = port_;

          bootstrap = new ServerBootstrap();

          bootstrap.group(new NioEventLoopGroup());
          bootstrap.channel(NioServerSocketChannel.class);
          bootstrap.localAddress(new InetSocketAddress(port));

          /**
           * Add handlers using anonymous class
          */

          /****PROBLEMATIC LINE*****/
          bootstrap.childHandler(new ChannelInitializer<SocketChannel>()
          {


            @Override
            protected void initChannel(SocketChannel ch) throws Exception {
                // TODO Auto-generated method stub
                System.out.println("hello");
            }

          }
          ); 


      }
}

public class simple_server
{

    public static void main(String args[])
    {
        server server_obj = new server(8080);
    }

}

我计划在 initChannel 方法中添加我的处理程序，但不知何故我无法编译当前程序。当我尝试编译这个示例程序时，我得到以下错误：

Exception in thread "main" java.lang.Error: Unresolved compilation problem: 
    Bound mismatch: The type SocketChannel is not a valid substitute for the bounded parameter <C extends Channel> of the type ChannelInitializer<C>

    at http_server.server.<init>
    at http_server.simple_server.main

知道到底出了什么问题吗？

Answer 1

您从错误的包中导入了 SocketChannel。

替换import java.nio.channels.SocketChannel;

import io.netty.channel.socket.SocketChannel;