java DataOutputStream异常

Question

第二次输入内容（在输入主机名后）第24行抛出异常 - 服务器正常工作。代码

import java.io.*; 
import java.net.*; 

class TCPclient { 
    public static void main(String[] args) throws Exception { 
     String hostname, msg; 
     InetAddress hostaddress; 
     BufferedReader inFromUser = new BufferedReader (new InputStreamReader(System.in)); 
     System.out.println("Please type host\n"); 
     hostname = inFromUser.readLine(); //I type localhost 
     hostaddress = InetAddress.getByName(hostname); 
     Socket cSocket = new Socket(hostaddress, 44444); 
     String cAddress = cSocket.getLocalSocketAddress().toString(); 
     DataOutputStream outToServer = new DataOutputStream (cSocket.getOutputStream()); 
     while (true) 
     { 
      msg = inFromUser.readLine(); 
      System.out.println(msg); 
      if (msg.equals("exit")) 
      { 
       System.out.println("exit"); 
       break; 
      } 
      outToServer.writeBytes(cAddress + " said : " + msg + '\n'); //this line throws an exception the second time it runs 
     } 
     cSocket.close(); 
    } 
} 

我是新来的java，所以我失去了一些显而易见的东西。异常写着：螺纹

异常 “主” java.net.SocketException异常：在java.net.SocketOutputStream.socketWrite0（本机方法） 插座写 错误 在java.net上：软件 导致连接中断.SocketOutputStream.java:92（SocketOutputStream.java:92） at java.net.SocketOutputStream.write（SocketOutputStream.java:115） at java.io.DataOutputStream.writeBytes（DataOutputStream.java:259） at TCPclient.main（TCPClient .java：52）Java 结果：1

服务器：

import java.io.*; 
import java.net.*; 

class TCPServer { 
    public static void main(String argv[]) throws Exception { 
     String clientSentence; 
     ServerSocket welcomeSocket = new ServerSocket(44444); 
     while(true) { 
     Socket connectionSocket = welcomeSocket.accept(); 
     BufferedReader inFromClient = new BufferedReader(
       new InputStreamReader(connectionSocket.getInputStream())); 
     clientSentence = inFromClient.readLine(); 
     System.out.println(clientSentence + "\n"); 
     } 
    } 
} 

Answer 1

您的客户端创建一个套接字，并再次写入遍地一个插座。您的服务器，而另一方面，这是否：

ServerSocket welcomeSocket = new ServerSocket(44444); 
while(true) { 
    Socket connectionSocket = welcomeSocket.accept(); 

接受传入连接，读取一行，然后放弃它（我猜的插座中的finalize被垃圾收集时，它关闭连接）。然后它等待一个新的连接。

所以要立即解决问题，请尝试while循环之前移动

Socket connectionSocket = welcomeSocket.accept(); 
    BufferedReader inFromClient = new BufferedReader(
      new InputStreamReader(connectionSocket.getInputStream())); 

。

Answer 2

打字第二行之间等待多久？这可能与套接字空闲有关。

此外，与这样的服务器代码，你只会看到第一条消息。试试这个：

import java.io.*; 
import java.net.*; 

class TCPServer { 
    public static void main(String argv[]) throws Exception { 
     String clientSentence; 
     ServerSocket welcomeSocket = new ServerSocket(44444); 
     Socket connectionSocket = welcomeSocket.accept(); 
     BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream())); 
     while (true) { 
      clientSentence = inFromClient.readLine(); 
      System.out.println(clientSentence + "\n"); 
     } 
    } 
} 

Answer 3

尝试：

while (true) 
{ 
    if(inFromUser.readLine() != null) 
    {   
     msg = inFromUser.readLine(); 

     System.out.println(msg); 
     if (msg.equals("exit")) 
     { 
      System.out.println("exit"); 
      break; 
     } 

     outToServer.writeBytes(cAddress + " said : " + msg + "\n"); 
    } 
} 

注意的变化：

if(inFromUser.readLine() != null) 
{ 

和

... "\n"); 

不

... '\n'); 

给它一个镜头。这可能是一个简单的解决方案，但它的东西:)