What's the difference between getPath(), getAbsolutePath(), and getCanonicalPath() in Java?

Question

What's the difference between `getPath()`, `getAbsolutePath()`, and `getCanonicalPath()` in Java? And when do I use each one?

Answer 1

The question revolves around the java.io.File core Java Class.

See example simple program and output below, but here's a reasonable definition for each.

1) Path - that file path string value that was passed to the File() constructor - see below.

2) Absolute Path - that file path string value after resolving the relative path to a full or absolute path - see below.

3) Canonical Path - goes one step beyond the absolute path name resolution, replace short-hand notations for current and parent directories, and symbolic links (short cuts) with the actual directory path - see below.

Note: if the path that was used to create the File object instance did not not reference a symbolic link or include and relative path notional such as ./ (current dir) or ../ (parent dir), then the Absolute and Canonical values will be the same.

// Test / POC Code

package my.package.path;

import java.io.File;

import java.io.IOException;

public class FilePathTester {

public static void main(String[] args) {

File file = new File("./poke.gif");

System.out.printf("Path = %s\n" ,file.getPath());

System.out.printf("Absolute Path = %s\n" ,file.getAbsolutePath());

try {

System.out.printf("Canoical Path = %s\n" , file.getCanonicalPath());

}

catch(IOException ioex) {

System.err.println(ioex);

}

}

}

Path = .\poke.gif

Absolute Path = C:\dev\workspaces_J\CSC330\.\poke.gif

Canoical Path = C:\dev\workspaces_J\CSC330\poke.gif