| /* |
| * Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.swing.filechooser; |
| |
| import java.io.File; |
| import java.util.Locale; |
| |
| /** |
| * An implementation of {@code FileFilter} that filters using a |
| * specified set of extensions. The extension for a file is the |
| * portion of the file name after the last ".". Files whose name does |
| * not contain a "." have no file name extension. File name extension |
| * comparisons are case insensitive. |
| * <p> |
| * The following example creates a |
| * {@code FileNameExtensionFilter} that will show {@code jpg} files: |
| * <pre> |
| * FileFilter filter = new FileNameExtensionFilter("JPEG file", "jpg", "jpeg"); |
| * JFileChooser fileChooser = ...; |
| * fileChooser.addChoosableFileFilter(filter); |
| * </pre> |
| * |
| * @see FileFilter |
| * @see javax.swing.JFileChooser#setFileFilter |
| * @see javax.swing.JFileChooser#addChoosableFileFilter |
| * @see javax.swing.JFileChooser#getFileFilter |
| * |
| * @since 1.6 |
| */ |
| public final class FileNameExtensionFilter extends FileFilter { |
| // Description of this filter. |
| private final String description; |
| // Known extensions. |
| private final String[] extensions; |
| // Cached ext |
| private final String[] lowerCaseExtensions; |
| |
| /** |
| * Creates a {@code FileNameExtensionFilter} with the specified |
| * description and file name extensions. The returned {@code |
| * FileNameExtensionFilter} will accept all directories and any |
| * file with a file name extension contained in {@code extensions}. |
| * |
| * @param description textual description for the filter, may be |
| * {@code null} |
| * @param extensions the accepted file name extensions |
| * @throws IllegalArgumentException if extensions is {@code null}, empty, |
| * contains {@code null}, or contains an empty string |
| * @see #accept |
| */ |
| public FileNameExtensionFilter(String description, String... extensions) { |
| if (extensions == null || extensions.length == 0) { |
| throw new IllegalArgumentException( |
| "Extensions must be non-null and not empty"); |
| } |
| this.description = description; |
| this.extensions = new String[extensions.length]; |
| this.lowerCaseExtensions = new String[extensions.length]; |
| for (int i = 0; i < extensions.length; i++) { |
| if (extensions[i] == null || extensions[i].length() == 0) { |
| throw new IllegalArgumentException( |
| "Each extension must be non-null and not empty"); |
| } |
| this.extensions[i] = extensions[i]; |
| lowerCaseExtensions[i] = extensions[i].toLowerCase(Locale.ENGLISH); |
| } |
| } |
| |
| /** |
| * Tests the specified file, returning true if the file is |
| * accepted, false otherwise. True is returned if the extension |
| * matches one of the file name extensions of this {@code |
| * FileFilter}, or the file is a directory. |
| * |
| * @param f the {@code File} to test |
| * @return true if the file is to be accepted, false otherwise |
| */ |
| public boolean accept(File f) { |
| if (f != null) { |
| if (f.isDirectory()) { |
| return true; |
| } |
| // NOTE: we tested implementations using Maps, binary search |
| // on a sorted list and this implementation. All implementations |
| // provided roughly the same speed, most likely because of |
| // overhead associated with java.io.File. Therefor we've stuck |
| // with the simple lightweight approach. |
| String fileName = f.getName(); |
| int i = fileName.lastIndexOf('.'); |
| if (i > 0 && i < fileName.length() - 1) { |
| String desiredExtension = fileName.substring(i+1). |
| toLowerCase(Locale.ENGLISH); |
| for (String extension : lowerCaseExtensions) { |
| if (desiredExtension.equals(extension)) { |
| return true; |
| } |
| } |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * The description of this filter. For example: "JPG and GIF Images." |
| * |
| * @return the description of this filter |
| */ |
| public String getDescription() { |
| return description; |
| } |
| |
| /** |
| * Returns the set of file name extensions files are tested against. |
| * |
| * @return the set of file name extensions files are tested against |
| */ |
| public String[] getExtensions() { |
| String[] result = new String[extensions.length]; |
| System.arraycopy(extensions, 0, result, 0, extensions.length); |
| return result; |
| } |
| |
| /** |
| * Returns a string representation of the {@code FileNameExtensionFilter}. |
| * This method is intended to be used for debugging purposes, |
| * and the content and format of the returned string may vary |
| * between implementations. |
| * |
| * @return a string representation of this {@code FileNameExtensionFilter} |
| */ |
| public String toString() { |
| return super.toString() + "[description=" + getDescription() + |
| " extensions=" + java.util.Arrays.asList(getExtensions()) + "]"; |
| } |
| } |