CODEWITHSUNDEEP
java
Program-Me-Rev
Program-Me-Rev

Reputation: 6624

How can I go about getting the parent directory of a directory

How can I go about getting the parent directory of a directory?

File parent = new File("");
System.out.println("Parent directory : " + parent.getParent());

prints Parent directory : null

I have a Maven multi-module project and would like to go to the parent folder then get back into each of the module folders and sub-folders getting all the jars in them.

parent  
    distributor  
        src.controllers  
            Dist.java  
    module1  
        src.controllers  
            1App.java  
        target  
            module1-1.0-SNAPSHOT.jar-  
    module2  
        src.controllers  
            2App.java  
        target  
            module2-1.0-SNAPSHOT.jar-

Above, I wold get from Dist.java to parent then into module1 and module2

Upvotes: 2

Views: 9914

Answers (1)

Andreas
Andreas

Reputation: 159096

Quoting javadoc of File.getParent() (emphasis mine):

Returns the pathname string of this abstract pathname's parent, or null if this pathname does not name a parent directory.

The parent of an abstract pathname consists of the pathname's prefix, if any, and each name in the pathname's name sequence except for the last. If the name sequence is empty then the pathname does not name a parent directory.

Remember, a File object represent the path string, not an actual file on the file system. The string "" does not have a parent. The string "a/b/c" has "a/b" as the parent, even if they don't physically exist.

So, first you have to resolve the path "" to a real path by calling getCanonicalFile(). Then you can find the parent directory.

File file = new File("").getCanonicalFile();
System.out.println("Parent directory : " + file.getParent());

Upvotes: 8

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