Java 客户端/服务器发送或获取 int 或 string 类型

Question

我正在尝试创建一个简单的java程序，其中客户端和服务器都能够发送和获取字符串和整数。我可以仅使用字符串或仅使用整数来完成它，但我发现很难将它们组合起来而不造成困惑。如果有人能告诉我最简单的方法，我将不胜感激。这是我到目前为止所做的，但它返回了错误的数字。

MyServer.java

package myserver;

import java.io.DataInputStream;
import java.util.Random;
import java.io.*;
import java.net.*;


public class MyServer 
{
   public static void main(String argv[]) throws Exception
      {
            String clientSentence;
            String answer;
            ServerSocket welcomeSocket = new ServerSocket(6789);
            Socket connectionSocket = welcomeSocket.accept();
            BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
            DataOutputStream outToClient = new DataOutputStream(connectionSocket.getOutputStream());
            clientSentence = inFromClient.readLine();
            Random rand = new Random();
            int  n = rand.nextInt(100) + 1;
            System.out.println("Received: " + clientSentence);
            answer = "Hey " + clientSentence + " guess a number from 1 to 100!" + '\n';
            outToClient.writeBytes(answer);
             DataInputStream integerFromClient = new DataInputStream(connectionSocket.getInputStream());
            int k = integerFromClient.readInt();
            System.out.println(k);

      }
} 

MyClient.java

package myserver;

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

class MyClient
{
 public static void main(String argv[]) throws Exception
 {
  String sentence;
  String modifiedSentence;
  BufferedReader inFromUser = new BufferedReader( new InputStreamReader(System.in));
  Socket clientSocket = new Socket("localhost", 6789);
  DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
  BufferedReader inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
  sentence = inFromUser.readLine();
  outToServer.writeBytes(sentence + '\n');
  modifiedSentence = inFromServer.readLine();
  System.out.println("SERVER: " + modifiedSentence);
  int k = inFromUser.read();
  outToServer.writeInt(k);
  clientSocket.close();
 }
}

Answer 1

我建议您使用包裹在 BufferedInputStream/BufferedOutputStream 周围的 DataInputStream/DataOutputStream。这将允许您发送

dos.writeUTF(string);
String s = dis.readUTF();

或

dos.writeInt(n);
int i = dis.readInt();

如果您不知道要写入什么类型，您可以使用这样的字节。

dos.writeByte('S');
dos.writeUTF(string);
dos.writeByte('i');
dos.writeInt(n);

和

for(int code; (code = dis.read()) != -1;) {
   switch(code) {
      case 'S':
            String s = dis.readUTF();
            process(s);
            break;
      case 'i':
            int i = dis.readInt();
            process(i);
            break;
      default:
            throw new StreamCorruptedException("code: "+code);
   }

}

您可以将其扩展为发送复杂的数据结构。