java - 已经抛出的 FileNotFoundException

Question

我这里有一个关于刽子手游戏的小代码(整体的一部分)以及它在编译时给出的错误。

import java.lang.*;
import java.io.*;
import java.util.*;

public class Hangman {

    //Properties

    private final int MAX_TRIES = 6;
    private StringBuffer secretWord; 
    private StringBuffer allLetters;
    private StringBuffer usedLetters;
    private int numberOfIncorrectTries;
    private int maxAllowedIncorrectTries;
    private StringBuffer knownSoFar;

    //Constructor   

    public Hangman() 
    {
        numberOfIncorrectTries = 0;
        maxAllowedIncorrectTries = MAX_TRIES;
        allLetters = new StringBuffer("abcdefghijklmnopqrstuvwxyz");
        usedLetters = new StringBuffer("");
        secretWord = chooseSecretWord();          //THIS IS LINE 33
        knownSoFar = new StringBuffer("");

        for (int count = 0; count < secretWord.length(); count++)
        {
            knownSoFar.append("*");
        }
    }


    //Methods

    public StringBuffer chooseSecretWord() throws FileNotFoundException{

        File file = new File("words.txt");
        Scanner scanner = new Scanner(file);

        final int NUMBER_OF_WORDS;
        int counter;
        int wordIndex;

        NUMBER_OF_WORDS = 99;

        StringBuffer[] words = new StringBuffer[NUMBER_OF_WORDS];

        //move all words to words array
        counter = 0; 
        while(scanner.hasNext())
        {
            StringBuffer newWord = new StringBuffer(scanner.next());
            words[counter++] = newWord;
        }
        //Find a random integer to get random index of array
        wordIndex = (int)(Math.random()*NUMBER_OF_WORDS);

        return words[wordIndex];
    } 

错误:

1 error found:
File: E:\Java\homeworks\Hangman\Hangman.java  [line: 33]
Error: unreported exception java.io.FileNotFoundException; must be caught or declared to be thrown

我花了一个小时试图找到原因，但什么也没看到。 Words.txt 文件与程序位于同一文件夹中，并且 ChooseSecretWord() 方法在主函数中工作(该函数是为了测试它而构建的)。我怀疑这是一个 PATH 问题，但不知道如何修复它。预先感谢您提供的任何帮助。

Answer 1

FileNotFoundException 是一个受检查的异常，这意味着您需要捕获或抛出它。如果你要扔或接住，这取决于你的设计，但它需要在某个地方完成。

所以你可以在这里抛出:

public Hangman() throws FileNotFoundException 

或者在这里捕获:

allLetters = new StringBuffer("abcdefghijklmnopqrstuvwxyz");
usedLetters = new StringBuffer("");
try {
    secretWord = chooseSecretWord();
} catch (FileNotFoundException e) {
    // TODO Do something here, example log the error our present a error message to the user.
}          //THIS IS LINE 33
knownSoFar = new StringBuffer("");

如果你想了解更多关于异常的知识；然后，docs.oracle.com 有一个关于异常的优秀教程:

https://docs.oracle.com/javase/tutorial/essential/exceptions/definition.html