循环程序以在完成检查后重新启动

Question

我正在尝试制作一个程序，用户将在a和b上输入字符串，程序将检查它是否被接受。现在，如果用户输入"exit"，我设法使程序退出，但是我无法弄清楚如何循环程序并在完成检查字符串时使其重新启动，要求用户再次输入。我应该怎么做？下面是我的代码

import java.util.Scanner; 
public class Automata {
public static void main(String[] args) {
    Boolean keeprunning = true;
    Scanner inputScanner = new Scanner(System.in);
    System.out.println("Please enter your input");
    String input = inputScanner.next();
    char [] Inputted = input.toCharArray();
    if (input.equalsIgnoreCase("Exit")){
        keeprunning = false;
        System.out.println("Exit now");
    }
    String stateA = "A";
    String stateB = "B";
    String stateC = "C";
    String stateD = "D";
    String stateE = "E";
    String stateF = "F";
    String currentState = "A";
    while(keeprunning){
    for (int i = 0; i < Inputted.length; i++){
        if (Inputted[i]=='a' && currentState.equals(stateA)){
            currentState = "B";
            System.out.println(stateA + " -- " + Inputted[i] + " --> " + stateB);
        } else if (Inputted[i]=='b' && currentState.equals(stateA)){
            currentState = "F";
            System.out.println(stateA + " -- " + Inputted[i] + " --> " + stateF);
        } 
        else if (Inputted[i] == 'a' && currentState.equals(stateB)){
            currentState = "B";
            System.out.println(stateB + " -- " + Inputted[i] + " --> " + stateB);
        } else if (Inputted[i] == 'b' && currentState.equals(stateB)){
            currentState = "C";
            System.out.println(stateB + " -- " + Inputted[i] + " --> " + stateC);
        } 
        else if (Inputted[i]== 'b' && currentState.equals(stateF)){
            currentState = "F";
            System.out.println(stateF + " -- " + Inputted[i] + " --> " + stateF);
        } else if (Inputted[i] == 'a' && currentState.equals(stateF)){
            currentState = "B";
            System.out.println(stateF + " -- " + Inputted[i] + " --> " + stateB);
        } 
        else if (Inputted[i] == 'a' && currentState.equals(stateC)){
            currentState = "D";
            System.out.println(stateC + " -- " + Inputted[i] + " --> " + stateD);
        } else if (Inputted[i] == 'b' && currentState.equals(stateC)){
            currentState = "F";
            System.out.println(stateC + " -- " + Inputted[i] + " --> " + stateF);
        } 
        else if (Inputted[i] == 'a' && currentState.equals(stateD)){
            currentState = "B";
            System.out.println(stateD + " -- " + Inputted[i] + " --> " + stateB);
        } else if (Inputted[i] == 'b' && currentState.equals(stateD)){
            currentState = "E";
            System.out.println(stateD + " -- " + Inputted[i] + " --> " + stateE);
        } 
        else if (Inputted[i] == 'a' && currentState.equals(stateE)){
            currentState = "B";
            System.out.println(stateE + " -- " + Inputted[i] + " --> " + stateB);
        } else if (Inputted[i] == 'b' && currentState.equals(stateE)){
            currentState = "C";
            System.out.println(stateE + " -- " + Inputted[i] + " --> " + stateC);
        }   
    } if (currentState.equals(stateA) || currentState.equals(stateB) || currentState.equals(stateD) || currentState.equals(stateE)){
        System.out.println("Input accepted");
        keeprunning = false;
        break;
    } else if (currentState.equals(stateF) || currentState.equals(stateC)){
        System.out.println("Input not accepted");
        keeprunning = false;
        break;
    }
}
    }

感谢您的任何帮助:D

Answer 1

只需将while循环标头移动到顶部，就在声明之后keeprunning：

Boolean keeprunning = true;
while(keeprunning){
...

并从语句中删除以下代码if-else：

keeprunning = false;
break;

这应该可以解决您所说的问题

---

import java.util.Scanner; 
public class Automata {
public static void main(String[] args) {
Boolean keeprunning = true;
while(keeprunning){
    Scanner inputScanner = new Scanner(System.in);
    System.out.println("Please enter your input");
    String input = inputScanner.next();
    char [] Inputted = input.toCharArray();
    if (input.equalsIgnoreCase("Exit")){
        keeprunning = false;
        System.out.println("Exit now");
    }
    else{
    String stateA = "A";
    String stateB = "B";
    String stateC = "C";
    String stateD = "D";
    String stateE = "E";
    String stateF = "F";
    String currentState = "A";

    for (int i = 0; i < Inputted.length; i++){
        if (Inputted[i]=='a' && currentState.equals(stateA)){
            currentState = "B";
            System.out.println(stateA + " -- " + Inputted[i] + " --> " + stateB);
        } else if (Inputted[i]=='b' && currentState.equals(stateA)){
            currentState = "F";
            System.out.println(stateA + " -- " + Inputted[i] + " --> " + stateF);
        } 
        else if (Inputted[i] == 'a' && currentState.equals(stateB)){
            currentState = "B";
            System.out.println(stateB + " -- " + Inputted[i] + " --> " + stateB);
        } else if (Inputted[i] == 'b' && currentState.equals(stateB)){
            currentState = "C";
            System.out.println(stateB + " -- " + Inputted[i] + " --> " + stateC);
        } 
        else if (Inputted[i]== 'b' && currentState.equals(stateF)){
            currentState = "F";
            System.out.println(stateF + " -- " + Inputted[i] + " --> " + stateF);
        } else if (Inputted[i] == 'a' && currentState.equals(stateF)){
            currentState = "B";
            System.out.println(stateF + " -- " + Inputted[i] + " --> " + stateB);
        } 
        else if (Inputted[i] == 'a' && currentState.equals(stateC)){
            currentState = "D";
            System.out.println(stateC + " -- " + Inputted[i] + " --> " + stateD);
        } else if (Inputted[i] == 'b' && currentState.equals(stateC)){
            currentState = "F";
            System.out.println(stateC + " -- " + Inputted[i] + " --> " + stateF);
        } 
        else if (Inputted[i] == 'a' && currentState.equals(stateD)){
            currentState = "B";
            System.out.println(stateD + " -- " + Inputted[i] + " --> " + stateB);
        } else if (Inputted[i] == 'b' && currentState.equals(stateD)){
            currentState = "E";
            System.out.println(stateD + " -- " + Inputted[i] + " --> " + stateE);
        } 
        else if (Inputted[i] == 'a' && currentState.equals(stateE)){
            currentState = "B";
            System.out.println(stateE + " -- " + Inputted[i] + " --> " + stateB);
        } else if (Inputted[i] == 'b' && currentState.equals(stateE)){
            currentState = "C";
            System.out.println(stateE + " -- " + Inputted[i] + " --> " + stateC);
        }   
    } if (currentState.equals(stateA) || currentState.equals(stateB) || currentState.equals(stateD) || currentState.equals(stateE)){
        System.out.println("Input accepted");
    } else if (currentState.equals(stateF) || currentState.equals(stateC)){
        System.out.println("Input not accepted");
    }
}   
}
}
}

Answer 2

最快的解决方案是在所有代码上添加一个while(true)循环（在main()的开头）

更好的解决方案是使用程序的逻辑创建一个可运行的线程，并在main()部分运行它。