Here you can find the source of isImg(String format)
public static boolean isImg(String format)
//package com.java2s; /*/*w ww .j a v a2 s. c o m*/ * Copyright 2017 Andrey Timofeev. * * 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 javax.imageio.ImageIO; public class Main { public static boolean isImg(String format) { String[] formatNames = ImageIO.getReaderFormatNames(); for (String name : formatNames) { if (name.equalsIgnoreCase(format)) { return true; } } return false; } }