java 小动画 源程序

import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.border.*; import java.io.*; public class CopyFile extends JFrame implements ActionListener { private JProgressBar jpb = new JProgressBar(); private JButton jbtCopy = new JButton("Copy"); private JTextField jtfFrom = new JTextField(); private JTextField jtfTo = new JTextField(); public CopyFile() { JPanel jPanel2 = new JPanel(); jPanel2.setLayout(new BorderLayout()); jPanel2.setBorder(new TitledBorder("From")); jPanel2.add(jtfFrom, BorderLayout.CENTER); JPanel jPanel3 = new JPanel(); jPanel3.setLayout(new BorderLayout()); jPanel3.setBorder(new TitledBorder("To")); jPanel3.add(jtfTo, BorderLayout.CENTER); JPanel jPanel1 = new JPanel(); jPanel1.setLayout(new GridLayout(2, 1)); jPanel1.add(jPanel2); jPanel1.add(jPanel3); JPanel jPanel4 = new JPanel(); jPanel4.add(jbtCopy); this.getContentPane().add(jpb, BorderLayout.NORTH); this.getContentPane().add(jPanel1, BorderLayout.CENTER); this.getContentPane().add(jPanel4, BorderLayout.SOUTH); jpb.setStringPainted(true); // Paint the percent in a string jbtCopy.addActionListener(this); } public void actionPerformed(ActionEvent e) { // Create a thread for copying files new CopyFileThread().start(); } public static void main(String[] args) { CopyFile frame = new CopyFile(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setTitle("CopyFile"); frame.setSize(400, 180); frame.setVisible(true); } // Copy file and update progress bar in a separate thread class CopyFileThread extends Thread { private int currentValue; public void run() { BufferedInputStream in = null; BufferedOutputStream out = null; try { // Create file input stream File inFile = new File(jtfFrom.getText().trim()); in = new BufferedInputStream(new FileInputStream(inFile)); // Create file output stream File outFile = new File(jtfTo.getText()); out = new BufferedOutputStream(new FileOutputStream(outFile)); // Get total bytes in the file long totalBytes = in.available(); // Start progress meter bar jpb.setValue(0); jpb.setMaximum(100); int r; long bytesRead = 0; // You may increase buffer size to improve IO speed byte[] b = new byte[10]; while ((r = in.read(b, 0, b.length)) != -1) { out.write(b, 0, r); bytesRead += r; currentValue = (int)(bytesRead * 100 / totalBytes); // Update the progress bar jpb.setValue(currentValue); } } catch (FileNotFoundException ex) { ex.printStackTrace(); } catch (IOException ex) { ex.printStackTrace(); } finally { try { if (in != null) in.close(); if (out != null) out.close(); } catch (Exception ex) {} } } } }