java - 重命名目录时重命名文件

Question

尝试重命名目录名和文件名。

try
    {
        File dir = new File("DIR");
        dir.mkdir();
        File file1 = new File(dir,"myfile1.txt");
        file1.createNewFile();
        File file2 = new File(dir,"myfile2.txt");
        file2.createNewFile();

        dir.renameTo(new File("myDIR"));            
        System.out.print(file1.renameTo(new File(dir,"myf1.txt")));
    }
    catch(IOException ie)
    {

    }

但是，只有目录被成功重命名，而文件名没有被成功重命名。
这些操作不能同时进行吗？

Answer 1

这是因为您的 dir、file1 和 file2 指向旧路径。

执行完这些行后，

File dir = new File("DIR");
dir.mkdir();
File file1 = new File(dir,"myfile1.txt");
file1.createNewFile();
File file2 = new File(dir,"myfile2.txt");
file2.createNewFile();

这些将是变量引用的路径，

dir = "DIR" // Exists
file1 = "DIR\myfile1.txt" //Exists
file2 = "DIR\myfile2.txt" //Exists

执行后，

    dir.renameTo(new File("myDIR"));            

变量引用的路径还是一样，

dir = "DIR" // Doesn't exist anymore because it's moved.
file1 = "DIR\myfile1.txt" // Doesn't exist anymore because it's moved along with dir.
file2 = "DIR\myfile2.txt" // Doesn't exist anymore because it's moved along with dir.

所以，当你打电话时，

    System.out.print(file1.renameTo(new File(dir,"myf1.txt")));

您正在对一个不存在的文件和一个也不存在的目录调用 renameTo()。所以它注定会失败。

即使您在 dir、file1 或 file2 上调用 .exists() 方法，它只会返回 false。