You can also use java.nio.file.Path
to do this much more easily. The java.nio.file.Path.startsWith
method seems to handle all possible cases.
Example:
private static void isChild(Path child, String parentText) {
Path parent = Paths.get(parentText).toAbsolutePath();
System.out.println(parentText + " = " + child.startsWith(parent));
}
public static void main(String[] args) {
Path child = Paths.get("/FolderA/FolderB/File").toAbsolutePath();
isChild(child, "/FolderA/FolderB/File");
isChild(child, "/FolderA/FolderB/F");
isChild(child, "/FolderA/FolderB");
isChild(child, "/FolderA/Folder");
isChild(child, "/FolderA");
isChild(child, "/Folder");
isChild(child, "/");
isChild(child, "");
}
Output:
/FolderA/FolderB/File = true
/FolderA/FolderB/F = false
/FolderA/FolderB = true
/FolderA/Folder = false
/FolderA = true
/Folder = false
/ = true
= false
If you need more reliability you can use toRealPath
instead of toAbsolutePath
.