java - 未处理的异常类型 FileNotFoundException

Question

主类:

public class cfung58_lab03_Main {
//main class 
//creates objects

    //Unhandled Exception Type FileNotFoundException occurs on the line below
static cfung58_lab03_Department myDepartment = new cfung58_lab03_Department(); 

...    
}

部门类别:

public class cfung58_lab03_Department {
    ....
    static  cfung58_lab03_Course[] coursesArray; 
static cfung58_lab03_Student[] studentArray; 

    public cfung58_lab03_Department() throws FileNotFoundException{
      File file = new File("Courses.txt");  //file for Courses.txt
    //System.out.println(file.getCanonicalPath());//gets path
    //File file2 = new File("Students.txt"); //file for Students.txt
    //System.out.println("True or false: " + file.canRead()); 
    if (file.exists()){
        //if the course file exists 

        //load scanner object to read file course.txt string
                    //NOTE: remember to throw FileException 
        Scanner read = new Scanner(file); 

        //count the number of Courses first before 
                    // creating the coursesArray and filling in the elements 
        int numberOfCourses = 0; 

        while (read.hasNext()){
            //String courseName = read.next(); 
            numberOfCourses++; 
        }

        //create coursesArray
        cfung58_lab03_Course[] coursesArray = new cfung58_lab03_Course[numberOfCourses];

        //restart the scanner system for read
        read = new Scanner(file); 

        while (read.hasNext()){
            String courseName = read.next(); 

            //for loop to fill in the elements for coursesArray
            for (int i = 0 ; i < numberOfCourses ; i++){
                //creating element 
                coursesArray[i] = new cfung58_lab03_Course(courseName, 0 );
            }

        }
    }
    //else throw exception 
    else 
        throw new FileNotFoundException("File could not be found."); 

尽管我已经在部门构造函数上抛出了异常，但我不确定是什么导致了编译器错误。

Eclipse也没有解决方案。

知道是什么原因造成的吗？

Answer 1

您正在从名称可怕的主类中调用一个方法，并且该方法抛出一个已检查的异常。所以这个异常需要被捕获(或抛出，但你不能在这里抛出它，因为你正在从方法中分配静态变量):

static cfung58_lab03_Department myDepartment;

static {
    try {
        myDepartment = new cfung58_lab03_Department(); 
    }
    catch (FileNotFoundException e) {
        throw new RuntimeException(e);
    }
}

也就是说，这个字段可能应该是你的 main 方法的局部变量。