Java 套接字命令行参数

Question

我用 java 创建了一个简单的服务器和客户端，它们可以相互发送和接收消息。目前我已将端口号硬编码到代码中，但我想将其更改为用户从命令行输入的内容。在下面的代码中，我使用 args[0] 作为端口号，但是当我编译它失败时，有人可以帮忙吗？我是 java 和套接字的新手，如果这是一个微不足道的问题，我很抱歉

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

class SimpleServer
{
 public static void main(String args[]) throws Exception
    {

      //declaring string variables
       String fromclient;
       String toclient;

       //new socket object, listening on port 3000
       ServerSocket Server = new ServerSocket (args[0]);

       //prints when started and no client connected
       System.out.println ("TCPServer Waiting for client on port 3000");

       //infinate loop
       while(true) 
       {

          //listens for connection
          Socket connected = Server.accept();

          //prints clients adddress and port
          System.out.println( " THE CLIENT"+" "+ connected.getInetAddress() +":"+connected.getPort()+" IS CONNECTED ");

          //reads in message form user
          BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));    

          //reads in message from clinet
          BufferedReader inFromClient = new BufferedReader(new InputStreamReader (connected.getInputStream()));

          //prints message to client 
          PrintWriter outToClient = new PrintWriter(connected.getOutputStream(),true);


          //infinate loop
          while ( true )
          {

              //printing instructions for killing connection
                System.out.println("SEND(Type Q or q to Quit):");

              //reading in user input
                toclient = inFromUser.readLine();

              //if user enters q or Q kill connection
                if ( toclient.equals ("q") || toclient.equals("Q") )
                {
                    outToClient.println(toclient);
                    connected.close();
                    break;
                }
                else
                {
                   outToClient.println(toclient);
              }

              //reading from client
                fromclient = inFromClient.readLine();

              //if user enter q or Q kill connection
              if ( fromclient.equals("q") || fromclient.equals("Q") )
              {
                    connected.close();
                    break;
              }

            //printing out the message from client
                else
                {
                  System.out.println( "RECIEVED:" + fromclient );
                } 

               }  

        }
    }
  }

这是即将出现的错误

SimpleServer.java:14: error: no suitable constructor found for ServerSocket(String)
     ServerSocket Server = new ServerSocket (args[0]);

Answer 1

ServerSocket Server = new ServerSocket (Integer.parseInt(args[0]));

args[0]是string，需要解析成int