Java 客户端-服务器程序中的静态方法没有正确分配它接收到的变量

Question

我制作的客户端-服务器程序有问题。客户端向服务器发送一个字符串，服务器应该识别它是'+'、'-'、'*'还是'/'并将其发送回客户端。问题是我做了一个静态方法应该识别符号，但它不起作用。它没有给我编译错误，所以我不知道我做错了什么。

客户：

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

   public class Client1{
   public static void main(String[] args){

    Socket client;
    InetSocketAddress isa;

    int letto;
    int dim_buffer = 100; 
    byte[] buffer;
    InputStream fromServer;
    OutputStream toServer;
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    String dataToServer = "";
    String dataFromServer = "";

    try{

        client = new Socket();
        isa = new InetSocketAddress(InetAddress.getLocalHost(), Integer.parseInt(args[0]));
        client.connect(isa);

        do{
            fromServer = client.getInputStream();
            toServer = client.getOutputStream();
            dataToServer = br.readLine();
            toServer.write(dataToServer.getBytes(), 0, dataToServer.length());
            buffer = new byte[dim_buffer];
            letto = fromServer.read(buffer);

            if(letto > 0){
                dataFromServer = new String(buffer, 0, letto);
                System.out.println("DATA FROM SERVER : " +dataFromServer);
            }else
                dataToServer = ".";

        }while(!(dataToServer.equals(".")));
        client.close();
    }catch(Exception e){
        e.printStackTrace();
    }

}
}

服务器

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

public class Server1{
public static void main(String[] args){

    ServerSocket server;
    Socket client;
    InputStream fromClient;
    OutputStream toClient;
    int dim_buffer = 100;
    byte[] buffer;
    String dataToClient = "";
    String dataFromClient = "";
    int letto;

    char operatore = '0';


    try{
        server = new ServerSocket(0);
        System.out.println("Porta server " + server.getLocalPort());

        while(true){

            client = server.accept();
            System.out.println("Connected with " + client.getInetAddress() + "; " + client.getPort());

            do{
                fromClient = client.getInputStream();
                toClient = client.getOutputStream();
                buffer = new byte[dim_buffer];
                letto = fromClient.read(buffer);
                if(letto > 0){
                    dataFromClient = new String(buffer, 0, letto);
                    System.out.println("DATO SENT FROM CLIENT: " + dataFromClient);
                    setOperatore(dataFromClient,operatore);
                    System.out.println("OP: " + Character.toString(operatore));
                    dataToClient = dataFromClient.toUpperCase();
                    toClient.write(dataToClient.getBytes(), 0, dataToClient.length());
                }else
                    dataFromClient = ".";

            }while(!(dataFromClient.equals(".")));
            client.close();
        }

    }catch(Exception e){
        e.printStackTrace();
    }
}

private static void setOperatore(String fromClientString, char operatore){  
    switch(fromClientString){
        case "+":
            operatore = fromClientString.charAt(0);
            break;
        case "-":
            operatore = fromClientString.charAt(0);
            break;
        case "*":
            operatore = fromClientString.charAt(0);
            break;
        case "/":
            operatore = fromClientString.charAt(0);
            break;
        default:
            break;
    }
 }
}

如果我为客户端打开一个终端，为服务器打开一个终端并在客户端终端上写“+”，这就是打印出来的内容。

服务器端：

    java Server1 
    Porta server 45225
    Connected with /127.0.0.1; 55342
    DATO SENT FROM CLIENT: +
    OP: 0

客户端：

    java Client1 45225
    +
    DATA FROM SERVER : +

它应该打印运营商：+ 而是打印 OP: 0

Answer 1

你应该让你的静态方法 return 成为你想要的值。在 Java.

中无法从方法中填充变量

    private static char getOperatore(String fromClientString){  
    char operatore;
    switch(fromClientString){
        case "+":
            operatore = fromClientString.charAt(0);
            break;
        case "-":
            operatore = fromClientString.charAt(0);
            break;
        case "*":
            operatore = fromClientString.charAt(0);
            break;
        case "/":
            operatore = fromClientString.charAt(0);
            break;
        default:
            break;
    }

    return operatore;
 }

Java 客户端-服务器程序中的静态方法没有正确分配它接收到的变量

Java static method in client-server program not assigning correctly variables it receives

java

static-methods

client-server