Question

所以，我正在尝试从套接字读取数据。我已经建立了一个连接并向另一个正在监听的套接字发送了一条消息，但它似乎没有收到任何信息。客户代码：

import java.net.*;
import java.io.*;
import java.util.*;
public class TCPClient {
 /*Conecting to server.
 */
 public static void Client(String[] args){
  int port = 47361;
  Scanner in = new Scanner(System.in);
  System.err.print("Starting up...");
  Socket CS1 = null; //Declaring CS1 as a socket
  DataOutputStream DOS1 = null; //Declaring an outputput data stream "DOS1"
  DataInputStream DIS1 = null; //Setting the values to null
  System.err.println("All created.");
  System.out.println("---------");
  System.out.println(" OPTIONS");
  System.out.println("---------");
  System.out.println("0. Connect.");
  System.out.println("1. Change port.");
  System.out.println("2. Cancel start-up.");
  System.out.println("");
  System.out.println("Choose an option.");
  try {
   short ans = in.nextShort();
   if (ans == 2){
    System.err.println("System.exit(0)");
    System.exit(0);
   }
   if (ans == 1){
     System.out.print("Enter the new port: ");
     port = in.nextInt();
     ans = 0;
   }
   if (ans == 0){
    System.out.print("Enter the IP: ");
    CS1 = new Socket(in.next(), port); //Creating an instane of the "CS1" socket
    System.err.print("Request sent on port " + port + ".");
    DOS1 = new DataOutputStream(CS1.getOutputStream());
    DIS1 = new DataInputStream(CS1.getInputStream()); //creating output and input streams
    System.err.println("Instances created!");
    if (DIS1 != null){
     System.err.println("DIS1 is connected!");
    }
    else {
     System.err.println("DIS1 is null!");
    }
    if (DOS1 != null) {
     System.err.println("DOS1 is connected!");
     System.out.print("Enter input: ");
     String FirstMessage = in.nextLine();
     DOS1.writeBytes(FirstMessage);
     String SecondMessage = DIS1.readLine();
     System.out.println(SecondMessage);
     if (SecondMessage.equals(FirstMessage)) {
     }
     else {
      System.out.println("Please check the code, FirstMessage != SecondMessage");
      }
    }
    else {
     System.err.println("DOS1 is null!");
    }
    if (CS1 != null) {
     System.err.println("CS1 is connected!");
    }
    else {
     System.err.println("CS1 is null!");
    }
    DIS1.close();
    DOS1.close();
    CS1.close(); //closing everything
   }
  }
  catch (IOException e){
   System.err.println("IOException: " + e.getMessage());
  }
 }
}

服务器代码：

import java.net.*;
import java.io.*;
import java.util.*;
public class TCPServer {
 /*Connecting to client
  */
 public static void Server (String[] args) {
  System.err.print("Starting up...");
  ServerSocket SS1 = null;
  DataOutputStream DOS1 = null;
  DataInputStream DIS1 = null;//Setting the values to null
  System.err.println("All created.");
  Scanner in = new Scanner(System.in);
  try {
   SS1 = new ServerSocket(47361); //setting the socket SS1 to port 5000 and creating an instance
   System.err.print("Listening on port 47361...");
   Socket CS1 = SS1.accept(); //accepting the connection request
   DOS1 = new DataOutputStream(CS1.getOutputStream());
   DIS1 = new DataInputStream(CS1.getInputStream());//creating output and input streams
   System.err.println("Instances created!");
   if (DIS1 != null){
    System.err.println("DIS1 is connected!");
    System.err.println(DIS1);
   }
   else {
    System.err.println("DIS1 is null!");
   }
   if (DOS1 != null) {
    System.err.println("DOS1 is connected!");
    System.err.println(DOS1);
   }
   else {
    System.err.println("DOS1 is null!");
   }
   if (SS1 != null) {
    System.err.println("SS1 is connected!");
    System.err.println(SS1);
   }
   else {
    System.err.println("SS1 is null!");
   }
   String FirstMessage = null;
   FirstMessage = DIS1.readLine();
   System.out.println(FirstMessage);
   String SecondMessage = FirstMessage;
   DOS1.writeBytes(SecondMessage);
   DIS1.close();
   DOS1.close();
   SS1.close(); //closing everything
  }
  catch (IOException error){
   System.err.println("IOException " + error.getMessage());
  }
catch (java.util.InputMismatchException error2){
   System.err.println("IOException " + error2.getMessage());
  }
 }
}

到目前为止，它几乎都是EchoServer，没有Buffered。我查看了调试器，它卡在服务器中的FirstMessage = DIS1.readLine();行和客户端中的String SecondMessage = DIS1.readLine();上。此外，即使在我输入任何可能的输入之后，服务器和客户端都在等待输入。为什么会发生这种情况？我怎样才能做到这一点？

旁注：我知道i / o流或套接字不会等于null。此外，编译器警告我不推荐使用java.io.DataInputStream类。您建议使用哪些其他课程？

另一方面注意：我是IO的新手，请不要因此而杀了我哈哈：）

谢谢！

Answer 1

常见问题。你正在读行，但你不是在写行。写信时在邮件中添加行终止符。

从套接字java中读取数据

1 个答案: