Java tutorial
//package com.java2s; /** * Copyright 2014 Zhenguo Jin * <p/> * 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 * <p/> * http://www.apache.org/licenses/LICENSE-2.0 * <p/> * 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 android.text.TextUtils; import java.io.File; public class Main { public final static String FILE_EXTENSION_SEPARATOR = ""; public static String getFileExtension(String filePath) { if (TextUtils.isEmpty(filePath)) { return filePath; } int extenPosi = filePath.lastIndexOf(FILE_EXTENSION_SEPARATOR); int filePosi = filePath.lastIndexOf(File.separator); if (extenPosi == -1) { return ""; } return (filePosi >= extenPosi) ? "" : filePath.substring(extenPosi + 1); } }