java - Jar 出现数组跳出异常，但 Eclipse 没有

Question

当我转换我的 Java 时项目到 Jar 文件中，ArrayIndexOutOfBounds -2 异常出现在这一段代码的第 3 行:

for (int i = 0; i < copy.get(copy.size() - 2).size(); i++) {
    if (!copy.get(copy.size() - 2).get(i).toString().equals(" ")) {
        startLocations[index] = Integer.parseInt(copy.get(copy.size() - 2).get(i).toString());
        index++;
    }
}

我觉得这很奇怪，因为程序在 Eclipse 中运行得很好，并且 copy 的大小，一个2D ArrayList暂时保留迷宫的网格是 9。当我将其转换为 Jar 并从 cmd 运行它时，代码失败。下面是完整的相关代码。所有文件都位于正确的位置。

String fileName = "maze.txt";
String line = null;
ArrayList < ArrayList < Square >> grid = new ArrayList < ArrayList < Square >> ();

try {
    // Setup FileReader, BufferedReader, and LineReader
    FileReader fileReader = new FileReader(fileName);
    BufferedReader bufferedReader = new BufferedReader(fileReader);

    int row = 0;

    // Get all the lines inside the maze file
    while ((line = bufferedReader.readLine()) != null) {
        ArrayList < Square > lineList = new ArrayList < Square > ();

        for (int i = 0; i < line.length(); i++) {
            String letter = Character.toString(line.charAt(i));

            if (letter.equals("L")) {
                lineList.add(new LockedSquare(row, i, letter));
            } else {
                lineList.add(new Square(row, i, letter));
            }

            row++;
        }

        grid.add(lineList);
    }

    // Cut down grid to only the maze

    ArrayList < ArrayList < Square >> copy = grid;

    int length = grid.size();

    grid = new ArrayList < ArrayList < Square >> ();

    for (int i = 0; i < length - 2; i++) {
        grid.add(copy.get(i));
    }

    // Start position

    int[] startLocations = new int[2];

    int index = 0;

    for (int i = 0; i < copy.get(copy.size() - 2).size(); i++) {
        if (!copy.get(copy.size() - 2).get(i).toString().equals(" ")) {
            startLocations[index] = Integer.parseInt(copy.get(copy.size() - 2).get(i).toString());
            index++;
        }
    }

    int playerX = startLocations[0];
    int playerY = startLocations[1];
}
// Exceptions
catch (FileNotFoundException e) {
    System.out.println("Error: maze.txt not found");
} catch (IOException ex) {
    System.out.println("Error reading maze.txt");
}

Answer 1

发生这种情况是因为您的 jar 文件无法找到 maze.txt .

更改String fileName = "maze.txt";到 String fileName = <absolute-path-for-maze.txt> ;它应该通过 jar