哈夫曼压缩与解压缩程序（JAVA）

import java.io.*; import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.filechooser.*; public class FileChooserDemo extends JPanel implements ActionListener { static private final String newline = "\n"; JButton openButton, saveButton; JTextArea log; JFileChooser fc; public FileChooserDemo() { 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("压缩文件...", 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("解压文件...", 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(FileChooserDemo.this); if (returnVal == JFileChooser.APPROVE_OPTION) { File file = fc.getSelectedFile(); //This is where a real application would open the file. log.append("正压缩文件: " + file.getAbsolutePath() + newline); try { Hzip.compress(file.getAbsolutePath()); log.append("已完成压缩: " + file.getAbsolutePath()+".huf" + newline); } catch (IOException error) { // TODO Auto-generated catch block error.printStackTrace(); log.append("错误:"+error.getMessage()); } } 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(FileChooserDemo.this); if (returnVal == JFileChooser.APPROVE_OPTION) { File file = fc.getSelectedFile(); //This is where a real application would save the file. log.append("解压: " + file.getAbsolutePath() + "" + newline); try { Hzip.uncompress(file.getAbsolutePath()); log.append("已完成解压: " + file.getAbsolutePath().substring(0, file.getAbsolutePath().length()-4)+ newline); } catch (IOException error) { // TODO Auto-generated catch block error.printStackTrace(); log.append("错误:"+error.getMessage()); } } 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 = FileChooserDemo.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 dispatch thread. */ private static void createAndShowGUI() { //Create and set up the window. JFrame frame = new JFrame("文件Huffman压缩与解压!"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Add content to the window. frame.add(new FileChooserDemo()); //Display the window. frame.pack(); frame.setVisible(true); } public static void main(String[] args) { //Schedule a job for the event dispatch thread: //creating and showing this application's GUI. SwingUtilities.invokeLater(new Runnable() { public void run() { //Turn off metal's use of bold fonts UIManager.put("swing.boldMetal", Boolean.FALSE); createAndShowGUI(); } }); } }