Here you can find the source of getFileExtension(Path path)
public static String getFileExtension(Path path)
//package com.java2s; /*//from w ww . ja v a2s . co m * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.nio.file.Path; public class Main { public static String getFileExtension(Path path) { String fileNameWithExt = path.getName(path.getNameCount() - 1) .toString(); int index = fileNameWithExt.lastIndexOf('.'); if (index != -1) return fileNameWithExt.substring(index + 1); else return null; } }