Here you can find the source of isValidRootArgument(Path argument)
protected static boolean isValidRootArgument(Path argument)
//package com.java2s; // copy, modify, merge, publish, distribute, sublicense, import java.nio.file.Files; import java.nio.file.Path; public class Main { protected static boolean isValidRootArgument(Path argument) { return (Files.exists(argument) && Files.isDirectory(argument)); }//from w w w .j a va 2 s.co m }