如何使用 File 对象获取文件的目录？

Question

Consider the code:

File file = new File("c:\\temp\\java\\testfile");

testfile is a file, and it may or may not exist. I want to get the directory c:\\\\temp\\\\java\\\\ using the File object. How do I go about doing this?

Answer 1

In either case, I'd expect file.getParent() (or file.getParentFile() ) to give you what you want.

Additionally, if you want to find out whether the original File does exist and is a directory, then exists() and isDirectory() are what you're after.

Answer 2

Java 文档中的File.getParent()

Answer 3

If you do something like this:

File file = new File("test.txt");
String parent = file.getParent();

parent will be null.

So to get directory of this file you can do next:

parent = file.getAbsoluteFile().getParent();

Answer 4

File API File.getParent or File.getParentFile should return you Directory of file.

Your code should be like :

    File file = new File("c:\\temp\\java\\testfile");
    if(!file.exists()){
        file = file.getParentFile();
    }

You can additionally check your parent file is directory using File.isDirectory API

if(file.isDirectory()){
    System.out.println("file is directory ");
}

Answer 5

File filePath=new File("your_file_path");
String dir="";
if (filePath.isDirectory())
{
    dir=filePath.getAbsolutePath();
}
else
{
    dir=filePath.getAbsolutePath().replaceAll(filePath.getName(), "");
}

Answer 6

File directory = new File("Enter any directory name or file name"); boolean isDirectory = directory.isDirectory(); if (isDirectory) { // It returns true if directory is a directory. System.out.println("the name you have entered is a directory : " + directory); //It returns the absolutepath of a directory. System.out.println("the path is " + directory.getAbsolutePath()); } else { // It returns false if directory is a file. System.out.println("the name you have entered is a file : " + directory); //It returns the absolute path of a file. System.out.println("the path is " + file.getParent()); }

Answer 7

String parentPath = f.getPath().substring(0, f.getPath().length() - f.getName().length()); 

这将是我的解决方案

Answer 8

6/10/2021 All current answers fail if eg. the given file is...

new File("." + File.separator + "."); //Odd, yes, but I've seen similar more often than you'd think is possible

For a simple, robust solution, try...

File givenFile = new File("." + File.separator + ".." + File.separator + "." + File.separator + "fakeFilename"); //The file or dir we want the parent of, whether it exists or not
File parentFile = new File(givenFile.getAbsolutePath() + File.separator + "..");
System.out.println(parentFile.getAbsolutePath());

Note that this answer assumes you want the actual parent directory on the filesystem , and not a File object representing the parent node of the given File object (which may be null, or may be the same directory as the given file).

EDIT: Also note that the internal filename is not succinct, and could in some cases grow with repeated usage. An equivalent solution without that issue would need to parse the entire absolute filename given by the above solution, and adjust the output, removing all instances of "." and ".." (the latter ofc would need to also remove the node before it, but only after all "." are removed)

Answer 9

你可以用这个

 File dir=new File(TestMain.class.getClassLoader().getResource("filename").getPath());

Answer 10

I found this more useful for getting the absolute file location.

File file = new File("\\TestHello\\test.txt");
System.out.println(file.getAbsoluteFile());