How to combine paths in Java?

novicer picture novicer · Jan 5, 2009 · Viewed 203k times · Source

Is there a Java equivalent for System.IO.Path.Combine() in C#/.NET? Or any code to accomplish this?

This static method combines one or more strings into a path.

Answer

Jon Skeet picture Jon Skeet · Jan 5, 2009

Rather than keeping everything string-based, you should use a class which is designed to represent a file system path.

If you're using Java 7 or Java 8, you should strongly consider using java.nio.file.Path; Path.resolve can be used to combine one path with another, or with a string. The Paths helper class is useful too. For example:

Path path = Paths.get("foo", "bar", "baz.txt");

If you need to cater for pre-Java-7 environments, you can use java.io.File, like this:

File baseDirectory = new File("foo");
File subDirectory = new File(baseDirectory, "bar");
File fileInDirectory = new File(subDirectory, "baz.txt");

If you want it back as a string later, you can call getPath(). Indeed, if you really wanted to mimic Path.Combine, you could just write something like:

public static String combine(String path1, String path2)
{
    File file1 = new File(path1);
    File file2 = new File(file1, path2);
    return file2.getPath();
}