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

Answer 1

Here is a canonical path.

C:/files/foo.txt

Here are absolute paths

• C:/files/FOO.TXT

• C:/files/FOO.txt

• C:/files/foo.TXT

• C:/FILES/FOO.TXT

A canonical path is an absolute unique path to the file. A file can have only one canonical path and many absolute paths.

A file can have only have one canonical path which is the file path of the file. A file can have many absolute paths to the file.

Answer 2

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.}

Answer 3

There can be many absolute paths to a file. However there can only be one canonical path to a file. Read this