what's the difference between canonicalpath and absolutepath? [duplicate]

Question

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

Any difference between those two?

canonicalpath and absolutepath?

If having difference, a real world example will be needed.

Answer 1

The difference is that there is only one canonical path to a file^[1], while there can be many absolute paths to a file (depending on the system). For instance, on a Unix system, /usr/local/../bin is the same as /usr/bin. getCanonicalPath() resolves those ambiguities and returns the (unique) canonical path. So if the current directory was /usr/local, then:

File file = new File("../bin"); System.out.println(file.getPath()); System.out.println(file.getAbsolutePath()); System.out.println(file.getCanonicalPath()); 

would print:

../bin
/usr/local/../bin
/usr/bin

Per Voo's suggestion: on Unix systems, getCanonicalPath() will also resolve symbolic links if the symbolic link exists. Hard links are treated like normal files (which is basically what they are). Note, however, that a file need not exist for these methods to succeed.

^[1]_{Well, not quite. As @Tom Hale points out in a comment, if the file system supports hard linked directories, there may be multiple canonical paths to a given file.}