Question

所以，我试图删除一个文件，但它不允许我......这是我的代码：

private static final File file = new File("data.dat");

public static void recreate() {
    try {
        if (file.exists()) {
            file.delete();
        }

        if (file.exists()) {
            throw new RuntimeException("Huh, what now?");
        }

        file.createNewFile();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

由于没有怀疑，它会抛出异常：

Exception in thread "main" java.lang.RuntimeException: Huh, what now?

有任何帮助吗？我做错了什么（可能只是一个derp ......）？

Answer 1

您可能没有该文件的写权限。在尝试删除该文件之前，您可以使用File#canWrite检查该文件的写入权限：

if (!file.canWrite()) {
    throw new RuntimeException("Sorry I don't have right permissions!");
}
// now you can try to delete it
if (file.exists()) {
            file.delete();
}

编辑：您还需要父目录的读/写/执行权限。您也可以添加这些检查：

if (!file.exists())
    throw new RuntimeException("file doesn't exist!");

File parent = file.getParentFile();

if (!parent.canRead() || !parent.canWrite() || !parent.canExecute())
    throw new RuntimeException("Sorry I don't have right permissions on dir!");

if (!file.canWrite())
    throw new RuntimeException("Sorry I don't have write permission on file!");

// now you can try to delete it
if (file.delete()) // check return value
    System.out.println("file deleted!!!");
 else
    throw new RuntimeException("Failed to delete the file");

Answer 2

我知道这不完全是你问的问题，但是既然你重新创建了文件，那该怎么样：

public static void recreate() {
    try (FileOutputStream fout = new FileOutputStream(file)) {
        // empty
    } catch (IOException e) {
         throw new RuntimeException(e);
    }
}

文件不删除

2 个答案: