用Java生成MD5值

JDK中已封裝了MD5類，所以實現起來也比較簡單

用兩個類完成了界面和實現過程

Digest.class

MainFrame.class

點擊下面的expand source可以查看代碼！

//實現生成MD5值 import java.io.BufferedInputStream; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; public class Digest { public Digest() { // TODO Auto-generated constructor stub } /** * @param args */ public static StringBuilder check(String path) { // TODO Auto-generated method stub StringBuilder sb = new StringBuilder(); byte[] size = null; StringBuilder noAlgorithm=new StringBuilder("無法使用MD5算法，這可能是你的JAVA虛擬機版本太低"); StringBuilder fileNotFound=new StringBuilder("未能找到文件，請重新定位文件路徑"); StringBuilder IOerror=new StringBuilder("文件輸入流錯誤"); try { MessageDigest md5=MessageDigest.getInstance("MD5");//生成MD5類的實例 File file = new File(path); //創建文件實例，設置路徑爲方法參數 FileInputStream fs = new FileInputStream(file); BufferedInputStream bi = new BufferedInputStream(fs); ByteArrayOutputStream bo = new ByteArrayOutputStream(); byte[] b = new byte[bi.available()]; //定義字節數組b大小爲文件的不受阻塞的可訪問字節數 int i; //將文件以字節方式讀到數組b中 while ((i = bi.read(b, 0, b.length)) != -1) { } md5.update(b);//執行MD5算法 for (byte by : md5.digest()) { sb.append(String.format("%02X", by));//將生成的字節MD５值轉換成字符串 } bo.close(); bi.close(); } catch (NoSuchAlgorithmException e) { // TODO Auto-generated catch block return noAlgorithm; } catch (FileNotFoundException e) { // TODO Auto-generated catch block return fileNotFound; } catch (IOException e) { // TODO Auto-generated catch block return IOerror; } return sb;//返回MD５值 } }

//生成窗體類爲主類 import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import javax.swing.*; import javax.swing.plaf.metal.MetalLookAndFeel; public class MainFrame extends JFrame implements ActionListener,MouseListener{ JTextField fileSource=new JTextField(36); JTextField produceMD5=new JTextField(36); JTextField showEqual=new JTextField("請在此處輸入源MD5值",36); JButton choiceFile=new JButton("選擇文件"); JButton createMD5=new JButton("生成MD5"); JButton judgement=new JButton("對比"); JPanel panel; JFileChooser fileChooser=new JFileChooser(); public MainFrame() { // TODO Auto-generated constructor stub super("MD5工具"); //設置主窗體的觀感爲金屬外觀 try { UIManager.setLookAndFeel(new MetalLookAndFeel()); } catch (UnsupportedLookAndFeelException e) { // TODO Auto-generated catch block e.printStackTrace(); } //窗體佈局使用GridBagLayout GridBagLayout gbl=new GridBagLayout(); GridBagConstraints gbc=new GridBagConstraints(); panel=new JPanel(gbl); panel.setBorder(BorderFactory.createTitledBorder("xiaohb's MD5 check tool")); gbc.fill=GridBagConstraints.BOTH; gbc.weightx=1.0; gbc.weighty=1.0; gbl.setConstraints(fileSource, gbc); panel.add(fileSource); gbc.weightx=0.0; gbc.gridwidth=GridBagConstraints.REMAINDER; gbl.setConstraints(choiceFile, gbc); panel.add(choiceFile); gbc.gridwidth=1; gbl.setConstraints(produceMD5, gbc); panel.add(produceMD5); gbc.weightx=0.0; gbc.gridwidth=GridBagConstraints.REMAINDER; gbl.setConstraints(createMD5, gbc); panel.add(createMD5); gbc.gridwidth=1; gbl.setConstraints(showEqual, gbc); panel.add(showEqual); gbc.weightx=0.0; gbc.gridwidth=GridBagConstraints.REMAINDER; gbl.setConstraints(judgement, gbc); panel.add(judgement); add(panel); //給按鈕添加註冊器 showEqual.addMouseListener(this); choiceFile.addActionListener(this); createMD5.addActionListener(this); judgement.addActionListener(this); } /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub MainFrame frame=new MainFrame(); frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE); frame.setSize(350, 200); frame.setResizable(false); frame.setVisible(true); } public void actionPerformed(ActionEvent e) { // TODO Auto-generated method stub Digest digest=new Digest(); JOptionPane prompt=new JOptionPane(); if(e.getSource()==choiceFile){ fileChooser.showOpenDialog(this); fileSource.setText(fileChooser.getSelectedFile().toString());//顯示選擇的文件名 }else if(e.getSource()==createMD5){ produceMD5.setText((digest.check(fileSource.getText())).toString());//生成的MD5值顯示在文本區域內 }else if(e.getSource()==judgement){ //判斷MD5值是否相同 if(produceMD5.getText().equalsIgnoreCase(showEqual.getText())){ prompt.showMessageDialog(this, "兩個MD5值相同，文件安全！"); }else{ prompt.showMessageDialog(this, "兩個MD5值不同，文件可能被篡改，請檢查！"); } } } public void mouseClicked(MouseEvent e) { // TODO Auto-generated method stub if(e.getSource()==showEqual){ showEqual.setText(""); } } public void mouseEntered(MouseEvent arg0) { // TODO Auto-generated method stub } public void mouseExited(MouseEvent arg0) { // TODO Auto-generated method stub } public void mousePressed(MouseEvent arg0) { // TODO Auto-generated method stub } public void mouseReleased(MouseEvent arg0) { // TODO Auto-generated method stub } }