一个Java JFileChooser例子,带有ActionEvent,ActionListener,insets,actionPerformed,showOpenDialog

・8 分钟阅读

这是Sun JFileChooser的一个Java示例,演示了如何使用JFileChooser,还显示了ActionEventActionListeneractionPerformedshowOpenDialog方法等。

/**
 * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * -Redistribution of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * -Redistribution in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * This software is provided\"AS IS,\" without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. (\"SUN\")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that this software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
 * nuclear facility.
 */
import java.awt.BorderLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JDialog;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
/**
 * SwingFileChooserDemo.java is a 1.4 application that uses these files:
 * images/Open16.gif images/Save16.gif
 */
public class SwingFileChooserDemo extends JPanel implements ActionListener {
 static private final String newline =\"n\";
 JButton openButton, saveButton;
 JTextArea log;
 JFileChooser fc;
 public SwingFileChooserDemo() {
 super(new BorderLayout());
 //Create the log first, because the action listeners
 //need to refer to it.
 log = new JTextArea(5, 20);
 log.setMargin(new Insets(5, 5, 5, 5));
 log.setEditable(false);
 JScrollPane logScrollPane = new JScrollPane(log);
 //Create a file chooser
 fc = new JFileChooser();
 //Uncomment one of the following lines to try a different
 //file selection mode. The first allows just directories
 //to be selected (and, at least in the Java look and feel,
 //shown). The second allows both files and directories
 //to be selected. If you leave these lines commented out,
 //then the default mode (FILES_ONLY) will be used.
 //
 //fc.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
 //fc.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
 //Create the open button. We use the image from the JLF
 //Graphics Repository (but we extracted it from the jar).
 openButton = new JButton(\"Open a File...\",
 createImageIcon(\"images/Open16.gif\"));
 openButton.addActionListener(this);
 //Create the save button. We use the image from the JLF
 //Graphics Repository (but we extracted it from the jar).
 saveButton = new JButton(\"Save a File...\",
 createImageIcon(\"images/Save16.gif\"));
 saveButton.addActionListener(this);
 //For layout purposes, put the buttons in a separate panel
 JPanel buttonPanel = new JPanel(); //use FlowLayout
 buttonPanel.add(openButton);
 buttonPanel.add(saveButton);
 //Add the buttons and the log to this panel.
 add(buttonPanel, BorderLayout.PAGE_START);
 add(logScrollPane, BorderLayout.CENTER);
 }
 public void actionPerformed(ActionEvent e) {
 //Handle open button action.
 if (e.getSource() == openButton) {
 int returnVal = fc.showOpenDialog(SwingFileChooserDemo.this);
 if (returnVal == JFileChooser.APPROVE_OPTION) {
 File file = fc.getSelectedFile();
 //This is where a real application would open the file.
 log.append(\"Opening:\" + file.getName() +\".\" + newline);
 } else {
 log.append(\"Open command cancelled by user.\" + newline);
 }
 log.setCaretPosition(log.getDocument().getLength());
 //Handle save button action.
 } else if (e.getSource() == saveButton) {
 int returnVal = fc.showSaveDialog(SwingFileChooserDemo.this);
 if (returnVal == JFileChooser.APPROVE_OPTION) {
 File file = fc.getSelectedFile();
 //This is where a real application would save the file.
 log.append(\"Saving:\" + file.getName() +\".\" + newline);
 } else {
 log.append(\"Save command cancelled by user.\" + newline);
 }
 log.setCaretPosition(log.getDocument().getLength());
 }
 }
 /** Returns an ImageIcon, or null if the path was invalid. */
 protected static ImageIcon createImageIcon(String path) {
 java.net.URL imgURL = SwingFileChooserDemo.class.getResource(path);
 if (imgURL != null) {
 return new ImageIcon(imgURL);
 } else {
 System.err.println(\"Couldn\'t find file:\" + path);
 return null;
 }
 }
 /**
 * Create the GUI and show it. For thread safety, this method should be
 * invoked from the event-dispatching thread.
 */
 private static void createAndShowGUI() {
 //Make sure we have nice window decorations.
 JFrame.setDefaultLookAndFeelDecorated(true);
 JDialog.setDefaultLookAndFeelDecorated(true);
 //Create and set up the window.
 JFrame frame = new JFrame(\"SwingFileChooserDemo\");
 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 //Create and set up the content pane.
 JComponent newContentPane = new SwingFileChooserDemo();
 newContentPane.setOpaque(true); //content panes must be opaque
 frame.setContentPane(newContentPane);
 //Display the window.
 frame.pack();
 frame.setVisible(true);
 }
 public static void main(String[] args) {
 //Schedule a job for the event-dispatching thread:
 //creating and showing this application\'s GUI.
 javax.swing.SwingUtilities.invokeLater(new Runnable() {
 public void run() {
 createAndShowGUI();
 }
 });
 }
}
Xn_warm profile image