Java错误: Default constructor cannot handle exception type FileNotFound Exception

Question

我正在尝试从文件中读取输入，并将其放入 Java 小程序中，以显示为吃 bean 人关卡，但我需要使用类似于 getLine() 的东西...所以我搜索了类似的东西，这是我找到的代码:

File inFile = new File("textfile.txt");
FileInputStream fstream = new FileInputStream(inFile);//ERROR
// Get the object of DataInputStream
DataInputStream in = new DataInputStream(fstream);
BufferedReader br = new BufferedReader(new InputStreamReader(in));

我标记为“错误”的行给出了一个错误，指出“默认构造函数无法处理隐式 super 构造函数抛出的异常类型 FileNotFoundException。必须定义显式构造函数。”

我已经搜索过此错误消息，但我找到的所有内容似乎与我的情况无关。

Answer 1

要么在子类中声明一个显式构造函数，该构造函数会抛出 FileNotFoundException:

public MySubClass() throws FileNotFoundException {
} 

或者用 try-catch block 包围基类中的代码，而不是抛出 FileNotFoundException 异常:

public MyBaseClass()  {
    FileInputStream fstream = null;
    try {
        File inFile = new File("textfile.txt");
        fstream = new FileInputStream(inFile);
        // Get the object of DataInputStream
        DataInputStream in = new DataInputStream(fstream);
        BufferedReader br = new BufferedReader(new InputStreamReader(in));
        // Do something with the stream
    } catch (FileNotFoundException ex) {
        Logger.getLogger(this.getClass().getName()).log(Level.SEVERE, null, ex);
    } finally {
        try {
            // If you don't need the stream open after the constructor
            // else, remove that block but don't forget to close the 
            // stream after you are done with it
            fstream.close();
        } catch (IOException ex) {
            Logger.getLogger(this.getClass().getName()).log(Level.SEVERE, null, ex);
        }
    }  
} 

不相关，但由于您正在编写 Java 小程序，请记住您将需要 sign it以便执行IO操作。