java - Converting Relative Paths to Absolute Paths

Question

I have an absolute path to file A.

I have a relative path to file B from file A's directory. This path may and will use ".." to go up the directory structure in arbitrarily complex ways.

Example A:

• C:projectsproject1module7submodule5fileA

Example Bs:

• ....module3submodule9subsubmodule32fileB
• ..submodule5fileB
• ....module7..module4submodule1fileB
• fileB

How do I combine the two in order to get the simplest possible absolute path to file B?

Answer 1

If I get your problem right, you could do something like this:

File a = new File("/some/abs/path");
File parentFolder = new File(a.getParent());
File b = new File(parentFolder, "../some/relative/path");
String absolute = b.getCanonicalPath(); // may throw IOException