If you need to compare the java.io.file.Path object, be aware that Path.endsWith(String) will ONLY match another sub-element of Path object in your original path, not the path name string portion! If you want to match the string name portion, you would need to call the Path.toString() first. For example // Match all jar files. Files.walk(dir).forEach(path -> { if (path. toString(). endsWith(".jar")) System.out.println(path); }); With out the " toString() " you will spend many fruitless hours wonder why your program didnt work.