关闭套接字问题答案

【问题标题】：Closed socket issue关闭套接字问题
【发布时间】：2016-01-10 23:51:09
【问题描述】：

试图编写一个回显文本的简单服务器，需要给它多个线程。 每当客户端连接时，我都会关闭套接字。我不太确定出了什么问题，而且我才刚刚开始学习这个，所以我不了解。如果有人能告诉我出了什么问题，我将不胜感激。 注意：这段代码显然没有完全完成，我主要只是需要解决上述问题。

import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.BufferedReader;

import java.io.OutputStream;
import java.io.PrintStream;

import java.net.ServerSocket;
import java.net.Socket;

import java.io.IOException;

public final class EchoServer 
{
    public static void main(String[] args) throws Exception 
    {
        try (ServerSocket serverSocket = new ServerSocket(22222)) 
        {
            while (true) 
            {
                try (Socket socket = serverSocket.accept()) 
                {
                    Thread newThread = new Thread(new server(socket));
                    newThread.start();
                }
            }
        }
    }
}
class server implements Runnable
{   
    Socket mySocket; 
    server(Socket s)
    {
        mySocket = s;
    }

    public void run()
    {
        //while(true)
        //{
            try
            {
                System.out.println("Client connected ");

                InputStream is = mySocket.getInputStream();
                InputStreamReader isr = new InputStreamReader(is, "UTF-8");
                BufferedReader br = new BufferedReader(isr);

                OutputStream os = mySocket.getOutputStream();
                PrintStream out = new PrintStream(os);

                String input = ("...");

                while(!input.equals("exit"))
                {   
                    input = br.readLine();
                    out.println("Server> " + input);
                }
            }
            catch(IOException e)
            {
                System.out.println(e);
            }
        //}
    }
}

【问题讨论】：

你应该阅读直到br.readLine()返回null

标签： java multithreading sockets runnable serversocket

【解决方案1】：

Try-with-resources 块在退出时会立即关闭资源，所以

try (Socket socket = serverSocket.accept()) 
{
  Thread newThread = new Thread(new server(socket));
  newThread.start();
}
// socket is closed by here, but newThread may still be running.

所以，只需删除 try:

Socket socket = serverSocket.accept();
Thread newThread = new Thread(new server(socket));
newThread.start();
// socket is still open here.

但请记住关闭server 类中的套接字（最终）。

【讨论】：

...所以删除 try 块。