Question

第二次输入内容时（第二次输入主机名后）第24行引发异常 - 服务器工作正常。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java的新手，所以我猜错了一些明显的东西。例外情况为：

线程“main”中的异常 java.net.SocketException：软件导致连接中止：套接字写入错误 at java.net.SocketOutputStream.socketWrite0（Native Method）在java.net.SocketOutputStream.socketWrite（SocketOutputStream.java:92）在java.net.SocketOutputStream.write（SocketOutputStream.java:115） at java.io.DataOutputStream.writeBytes（DataOutputStream.java:259）在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反复写入该一个套接字。另一方面，您的服务器执行此操作：

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

接受传入的连接，读取一行，然后放弃它（我猜测套接字的最终结果是垃圾收集它关闭连接）。然后它等待新的连接。

因此，要解决您的问题，请尝试移动

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

在while循环之前

。

Answer 2

在输入第二行之间等待多长时间？它可能与套接字空闲有关。

同样使用这样的服务器代码，您将只看到第一条消息。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");
    }
}

请注意更改：

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

和

... "\n");

不

... '\n');

试一试。这可能是一个简单的解决方案，但它是：）

java DataOutputStream异常

3 个答案: