edit:it was 我的一个错误，错误地改变了测试输入。它现在像一个魅力：）谢谢你们的帮助！如果你想的话，你可以结束这个问题。
我有一个任务，应该读取用户输入（测试文件）并返回一些数据（输出）。一切都运行良好，我通过了我的测试2，但由于一些愚蠢的错误，在我的结束流关闭（通过测试后）。
main处理用户输入并声明和运行scanner，它调用我创建的类中的方法（由于赋值限制，我无法更改main）。
这是我在课堂上写的代码：

public class MyInstance extends Intersection {

private boolean methodHasRun = false;
//  keeps count of getIntersectionState() loop
    private static int loop_count;

public String getIntersectionState(){

        String left = "LVg0";
        String right = "RVg0";
        String bottom = "BVr0";
        String top = "TVr0";
        String temp = " ";
        String temp1 = " ";
        String temp2 = " ";
        String temp3 = " ";
        String nr [] = {"1","2","3","4","5","6","7","8","9","10"};

//      if advanceTime() was executed
        if (this.methodHasRun) {

            //get last char, write it to temp
            temp = bottom.substring(bottom.length()-1).trim();  
            temp1 = top.substring(top.length()-1).trim();
            while(loop_count < nr.length-1) { 
                temp = "BVr" + nr[loop_count];
                temp1 = "TVr" + nr[loop_count];
                ++loop_count;
//              break after each increment
                break;
            }
            if(loop_count == 9) {
                temp = "BVr" + nr[8];
                temp1 = "TVr" + nr[8]; 
                ++loop_count;
            }else if(loop_count > 9) {
                while(loop_count < 20) {                
                temp = "BVg" + nr[8];
                temp1 = "TVg" + nr[8];
                temp2 = "LVr" + nr[loop_count-10];
                temp3 = "RVr" + nr[loop_count-10];
                ++loop_count; 
//              can't save left and right out of else if
//              because they will be assigned to: " "
                left = temp2;
                right = temp3;
                break;
                }
            }

            if(loop_count == 21) {
                temp = "BVg" + nr[9];
                temp1 = "TVg" + nr[9];
                temp2 = "LVr" + nr[9];
                temp3 = "RVr" + nr[9];

                left = temp2;
                right = temp3;
            }
            while(loop_count == 20) {
                temp2 = "LVr" + nr[9];
                temp3 = "RVr" + nr[9];
                ++loop_count;
                break;
            }
            if (loop_count > 21) {
                System.out.println("go on");
            }
            bottom = temp;
            top = temp1;

//          System.out.println("State changed!"+
//                  "\nLoop count is: "+loop_count);

//          revert to false until state changes again
            this.methodHasRun = false;

            } else {
            System.out.println("State hasn't changed");
            }
        return left +" "+ right +" "+ bottom +" "+ top;
    }
}

它在运行时生成：

测试输入文件是：

state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state
vehicle left
vehicle right
vehicle bottom
vehicle top
step
state

应输出：

LVg0 RVg0 BVr0 TVr0
LVg0 RVg0 BVr1 TVr1
LVg0 RVg0 BVr2 TVr2
LVg0 RVg0 BVr3 TVr3
LVg0 RVg0 BVr4 TVr4
LVg0 RVg0 BVr5 TVr5
LVg0 RVg0 BVr6 TVr6
LVg0 RVg0 BVr7 TVr7
LVg0 RVg0 BVr8 TVr8
LVg0 RVg0 BVr9 TVr9
LVr1 RVr1 BVg9 TVg9
LVr2 RVr2 BVg9 TVg9
LVr3 RVr3 BVg9 TVg9
LVr4 RVr4 BVg9 TVg9
LVr5 RVr5 BVg9 TVg9
LVr6 RVr6 BVg9 TVg9
LVr7 RVr7 BVg9 TVg9
LVr8 RVr8 BVg9 TVg9
LVr9 RVr9 BVg9 TVg9
LVr10 RVr10 BVg9 TVg9
LVg10 RVg10 BVr10 TVr10

我希望有人能理解我的错误或提出一些建议。