生成文件的Hash码MD5

import javax.print.DocFlavor.URL; import javax.swing.*; import java.awt.event.*; import java.io.*; import java.security.DigestInputStream; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.awt.*; public class FileTest implements ActionListener{ JFrame f; TextArea ta; JFileChooser fc; Container c; File myFile; JButton jb1=new JButton("生成视频文件hash值"); JButton jb2=new JButton("保存hash文件列表到videohash.txt"); JPanel jpl=new JPanel(); String hash=""; public static void main(String args[]){ FileTest demo=new FileTest(); demo.go(); } void go(){ JFrame f=new JFrame("获得视频文件的Hash "); ta=new TextArea("",10,30,TextArea.SCROLLBARS_BOTH); jb1.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { //JOptionPane.showMessageDialog(null,"弹出对话框"); fc=new JFileChooser(); java.net.URL dir=FileTest.class.getProtectionDomain().getCodeSource().getLocation(); String path=dir.getPath()+"VVDown"; fc.setCurrentDirectory(new File(path)); int selected=fc.showOpenDialog(c); if (selected==JFileChooser.APPROVE_OPTION){ myFile=fc.getSelectedFile(); String VideoInfo; try { VideoInfo = fileMD5(myFile.getAbsolutePath()); hash+=myFile.getAbsolutePath()+" "+VideoInfo+"\r\n"; ta.setText(hash); } catch (IOException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } } } }); jb2.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { java.net.URL dir=FileTest.class.getProtectionDomain().getCodeSource().getLocation(); String path=dir.getPath()+"VVDown/videohash.txt"; String text = ta.getText(); String[] lines = text.split("\n"); FileWriter fw; try { fw = new FileWriter(path); BufferedWriter bw = new BufferedWriter(fw); for (int i = 0; i < lines.length; i++) { bw.write(lines[i] + "\r\n"); } bw.close(); } catch (IOException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } JOptionPane.showMessageDialog(null,"保存"); } }); c=f.getContentPane(); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); jpl.add(jb1); jpl.add(jb2); f.getContentPane().add("North",jpl); f.getContentPane().add("Center",ta); f.setLocation(300, 200); f.setSize(800,600); f.setVisible(true); } public static String byteArrayToHex(byte[] byteArray) { // 首先初始化一个字符数组，用来存放每个16进制字符 char[] hexDigits = {'0','1','2','3','4','5','6','7','8','9', 'a','b','c','d','e','f' }; // new一个字符数组，这个就是用来组成结果字符串的（解释一下：一个byte是八位二进制，也就是2位十六进制字符（2的8次方等于16的2次方）） char[] resultCharArray =new char[byteArray.length * 2]; // 遍历字节数组，通过位运算（位运算效率高），转换成字符放到字符数组中去 int index = 0; for (byte b : byteArray) { resultCharArray[index++] = hexDigits[b>>> 4 & 0xf]; resultCharArray[index++] = hexDigits[b& 0xf]; } // 字符数组组合成字符串返回 return new String(resultCharArray); } public String fileMD5(String inputFile) throws IOException { // 缓冲区大小（这个可以抽出一个参数） int bufferSize = 256 * 1024; FileInputStream fileInputStream = null; DigestInputStream digestInputStream = null; try { // 拿到一个MD5转换器（同样，这里可以换成SHA1） MessageDigest messageDigest =MessageDigest.getInstance("MD5"); // 使用DigestInputStream fileInputStream = new FileInputStream(inputFile); digestInputStream = new DigestInputStream(fileInputStream,messageDigest); // read的过程中进行MD5处理，直到读完文件 byte[] buffer =new byte[bufferSize]; while (digestInputStream.read(buffer) > 0); // 获取最终的MessageDigest messageDigest= digestInputStream.getMessageDigest(); // 拿到结果，也是字节数组，包含16个元素 byte[] resultByteArray = messageDigest.digest(); // 同样，把字节数组转换成字符串 return byteArrayToHex(resultByteArray); } catch (NoSuchAlgorithmException e) { return null; } finally { try { digestInputStream.close(); } catch (Exception e) { } try { fileInputStream.close(); } catch (Exception e) { } } } public void actionPerformed(ActionEvent e){ } }