java - Java套接字错误

Question

我尝试创建使用Socket的程序。
我想输入单词，然后将其送回给我。
第一次，它似乎工作正常，但第二次失败。

这是我的源代码。

- - - - - - - - - - -服务器 - - - - - - - - - -

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class ServerTestClass {                     
    public static void main(String[] args) {
        ServerSocket welcome = null;
        Socket Sock = null;
        try{
            welcome = new ServerSocket(45678);
        }catch(IOException e){
            System.err.println("error");
        }

        while(true){
            try{
                Sock = welcome.accept();
                EchoThread echoThread = new EchoThread(Sock,45678);
                echoThread.start();
            }catch(IOException e){
                System.err.println("error 1");
            }
        }
    }
}
class EchoThread extends Thread{
    Socket Sock ;
    int port;
    EchoThread(Socket Sock,int port){
        this.port = port;
        this.Sock = Sock;
    }
    public void run(){
        OutputStreamWriter output = null;
        BufferedReader input = null;
        try{
            output = new OutputStreamWriter(Sock.getOutputStream());
            input = new BufferedReader(new InputStreamReader(Sock.getInputStream()));
            while(true){
                String word = input.readLine();
                output.write(": "+word);
                output.flush();
                output.close();
                input.close();
                Sock.close();
                break;
            }
        }catch(IOException e){
            System.err.println("error 2");
        }
        finally{
            try{
                if(output != null){
                    output.close();
                }
                if(input != null){
                    input.close();
                }
                if(Sock != null){
                    Sock.close();
                }
            }catch(IOException e){
                e.printStackTrace();
            }
        }  
    }
}

- - - - - - - - - 客户 - - - - - - - -

package client;
import java.net.*;
import java.io.*;
import java.util.*;
public class Client
{
    public static final int PORT = 45678;  // default port
    public static void main(String[] args)
    {
        Socket clientSocket = null;
        int port = PORT;
        String hostName = null;

        try
        { // create socket
          clientSocket = new Socket("localhost", port);
        }
        catch (IOException e)
        {
            System.err.println("Error Creating Socket");
            System.exit(2);
        }
        catch (NumberFormatException e) {
            System.out.println("Port number must be integer between 1024 and 65535");
            System.exit(3);
        }
        OutputStreamWriter output = null;
        Scanner input = null;
        try
        {
            output = new OutputStreamWriter(clientSocket.getOutputStream());
            input = new Scanner(clientSocket.getInputStream());
            Scanner inputData = new Scanner(System.in);     
            while(true) {
                System.out.println("Enter your word: ");
                String inputWord = inputData.nextLine();
                output.write(inputWord + "\r\n");
                output.flush();
                if (inputWord.equals(""))
                {
                    break;
                }
                String outputWord = input.nextLine();
                System.out.println(outputWord);
            }
            input.close();
            output.close();
            clientSocket.close();
        } catch (IOException e)
        {
            System.err.println("Closing Socket connection");
        }
        finally {
            try {
                if (input != null)
                    input.close();
                if (output != null)
                    output.close();
                if (clientSocket != null)
                    clientSocket.close();
            } 
            catch (IOException e) {
                e.printStackTrace(); 
            }
        }
    }
}

- - - - - - - - - - - -结果 - - - - - - - - - - - - - --

run:
Enter your word: 
word
: word
Enter your word: 
word
Exception in thread "main" java.util.NoSuchElementException: No line found
    at java.util.Scanner.nextLine(Scanner.java:1540)
    at client.Client.main(Client.java:49)
Java Result: 1
BUILD SUCCESSFUL (total time: 18 seconds)

Answer 1

 while(true) {
   System.out.println("Enter your word: ");
   String inputWord = ""; 

   inputword = inputData.nextLine();
   output.write(inputWord + "\r\n");
   output.flush();


   if (inputWord.equals(""))
   {
                                break;
   }
   //String outputWord = input.nextLine();
   //System.out.println(outputWord); no need of the commented lines
  }

 }

这是您从那里获取异常的地方，即使您修复了此异常bt，也可以获取一些异常，而当前的问题也已解决。如果没有行要读取，那就一定不要强行读取行。也许你应该试试这个