Here you can find the source of getFilterExtensions(FileNameExtensionFilter... filters)
public static String[] getFilterExtensions(FileNameExtensionFilter... filters)
//package com.java2s; /*//from ww w . j ava 2s .c o m * Copyright [2016] [Mannheim University of Applied Sciences] * * 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.util.Arrays; import java.util.stream.Stream; import javax.swing.filechooser.FileNameExtensionFilter; public class Main { public static String[] getFilterExtensions(FileNameExtensionFilter... filters) { return filters != null ? Arrays.stream(filters).map(filter -> filter.getExtensions()) .reduce((extensionsA, extensionsB) -> Stream .concat(Arrays.stream(extensionsA), Arrays.stream(extensionsB)).toArray(String[]::new)) .get() : null; } }