--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/swing/filechooser/FileNameExtensionFilter.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,158 @@
+/*
+ * Copyright 2006 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.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()) + "]";
+ }
+}