Here you can find the source of isAbsolutePath(String path)
public static boolean isAbsolutePath(String path)
//package com.java2s; //License from project: Apache License public class Main { public static final String SLASH = "/"; public static boolean isAbsolutePath(String path) { if (path == null || path.trim().length() == 0) { throw new NullPointerException("Path can't be null or empty."); }//from www. j a v a2 s . c o m return path.startsWith(SLASH); } }