import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.io.*; import java.security.*; import javax.crypto.*; import javax.crypto.spec.*; /** 文件名：FileEncrypter.java JDK：1.40以上 说明：文件加密 加密方法：三重DES加密 加密过程： 对选中的文件加密后在同文件夹下生成一个增加了".tdes" 扩展名的加密文件 解密过程：对选中的加密文件（必须有".tdes"扩展名）进行解密 */ public class FileEncrypter extends JFrame{ public static final int WIDTH = 550; public static final int HEIGHT = 200; public static void main(String args[]) { FileEncrypter fe = new FileEncrypter(); fe.show(); }

FileEncrypter(){   this.setSize(WIDTH,HEIGHT);   this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   this.setResizable(false);   Toolkit tk = Toolkit.getDefaultToolkit();   Dimension screenSize = tk.getScreenSize();   this.setLocation((screenSize.width - WIDTH)/2, (screenSize.height - HEIGHT)/2);   this.setTitle("文件加密器(TriDES)");   Container c = this.getContentPane();   c.setLayout( new FlowLayout());   final FilePanel fp = new FilePanel("文件选择");   c.add(fp);   final KeyPanel pp = new KeyPanel("密码");   c.add(pp);   JButton jbE = new JButton("加密");   c.add(jbE);   jbE.addActionListener(new ActionListener(){   public void actionPerformed(ActionEvent event){   File file = new File(fp.getFileName());   if (file.exists())     encrypt(file.getAbsoluteFile(),pp.getKey());   else     JOptionPane.showMessageDialog(   null,"请选择文件！","提示",JOptionPane.OK_OPTION);  }  });   JButton jbD = new JButton("解密");   c.add(jbD);   jbD.addActionListener(new ActionListener(){     public void actionPerformed(ActionEvent event){      File file = new File(fp.getFileName());      if (file.exists())       decrypt(file.getAbsoluteFile(),pp.getKey());      else       JOptionPane.showMessageDialog(null,"请选择文件！","提示",JOptionPane.OK_OPTION);    }   });  } /** 加密函数 输入： 要加密的文件，密码（由0-F组成，共48个字符，表示3个8位的密码）如： AD67EA2F3BE6E5ADD368DFE03120B5DF92A8FD8FEC2F0746 其中： AD67EA2F3BE6E5AD DES密码一 D368DFE03120B5DF DES密码二 92A8FD8FEC2F0746 DES密码三 输出： 对输入的文件加密后，保存到同一文件夹下增加了".tdes"扩展名的文件中。 */ private void encrypt(File fileIn,String sKey){   try{    if(sKey.length() == 48){      byte[] bytK1 = getKeyByStr(sKey.substring(0,16));      byte[] bytK2 = getKeyByStr(sKey.substring(16,32));      byte[] bytK3 = getKeyByStr(sKey.substring(32,48));      FileInputStream fis = new FileInputStream(fileIn);      byte[] bytIn = new byte[(int)fileIn.length()];      for(int i = 0;i< fileIn.length();i++){       bytIn[i] = (byte)fis.read();      }     //加密     byte[] bytOut = encryptByDES(encryptByDES(encryptByDES(bytIn,bytK1),bytK2),bytK3);     String fileOut = fileIn.getPath() + ".tdes";     FileOutputStream fos = new FileOutputStream(fileOut);     for(int i = 0;i< bytOut.length;i++){       fos.write((int)bytOut[i]);     }     fos.close();     JOptionPane.showMessageDialog(this,"加密成功！","提示",JOptionPane.OK_OPTION);   }else     JOptionPane.showMessageDialog(     this,"密码长度必须等于48！","错误信息",JOptionPane.ERROR_MESSAGE);   }catch(Exception e){          e.printStackTrace();    }  } 

/** 解密函数 输入： 要解密的文件，密码（由0-F组成，共48个字符，表示3个8位的密码）如： AD67EA2F3BE6E5ADD368DFE03120B5DF92A8FD8FEC2F0746 其中： AD67EA2F3BE6E5AD DES密码一 D368DFE03120B5DF DES密码二 92A8FD8FEC2F0746 DES密码三 输出： 对输入的文件解密后，保存到用户指定的文件中。 */ private void decrypt(File fileIn,String sKey){   try{     if(sKey.length() == 48){       String strPath = fileIn.getPath();       if(strPath.substring(strPath.length()-5).toLowerCase().equals(".tdes"))         strPath = strPath.substring(0,strPath.length()-5);       else{         JOptionPane.showMessageDialog(this,"不是合法的加密文件！","提示",JOptionPane.OK_OPTION);         return;       }       JFileChooser chooser = new JFileChooser();       chooser.setCurrentDirectory(new File("."));       chooser.setSelectedFile(new File(strPath));       //用户指定要保存的文件       int ret = chooser.showSaveDialog(this);       if(ret==JFileChooser.APPROVE_OPTION){         byte[] bytK1 = getKeyByStr(sKey.substring(0,16));         byte[] bytK2 = getKeyByStr(sKey.substring(16,32));         byte[] bytK3 = getKeyByStr(sKey.substring(32,48));         FileInputStream fis = new FileInputStream(fileIn);         byte[] bytIn = new byte[(int)fileIn.length()];         for(int i = 0;i< fileIn.length();i++){             bytIn[i] = (byte)fis.read();         }      //解密      byte[] bytOut = decryptByDES(decryptByDES(decryptByDES(bytIn,bytK3),bytK2),bytK1);      File fileOut = chooser.getSelectedFile();      fileOut.createNewFile();      FileOutputStream fos = new FileOutputStream(fileOut);      for(int i = 0;i< bytOut.length;i++){           fos.write((int)bytOut[i]);       }      fos.close();      JOptionPane.showMessageDialog(this,"解密成功！","提示",JOptionPane.OK_OPTION);     }    }else       JOptionPane.showMessageDialog(this,"密码长度必须等于48！","错误信息",JOptionPane.ERROR_MESSAGE);   }catch(Exception e){       JOptionPane.showMessageDialog(this,"解密失败，请核对密码！","提示",JOptionPane.OK_OPTION);   } } /** 用DES方法加密输入的字节 bytKey需为8字节长，是加密的密码 */ private byte[] encryptByDES(byte[] bytP,byte[] bytKey) throws Exception{    DESKeySpec desKS = new DESKeySpec(bytKey);    SecretKeyFactory skf = SecretKeyFactory.getInstance("DES");    SecretKey sk = skf.generateSecret(desKS);    Cipher cip = Cipher.getInstance("DES");    cip.init(Cipher.ENCRYPT_MODE,sk);    return cip.doFinal(bytP); } /** 用DES方法解密输入的字节 bytKey需为8字节长，是解密的密码 */  private byte[] decryptByDES(byte[] bytE,byte[] bytKey) throws Exception{    DESKeySpec desKS = new DESKeySpec(bytKey);    SecretKeyFactory skf = SecretKeyFactory.getInstance("DES");    SecretKey sk = skf.generateSecret(desKS);    Cipher cip = Cipher.getInstance("DES");    cip.init(Cipher.DECRYPT_MODE,sk);     return cip.doFinal(bytE);  } /** 输入密码的字符形式，返回字节数组形式。 如输入字符串：AD67EA2F3BE6E5AD 返回字节数组：{173,103,234,47,59,230,229,173} */ private byte[] getKeyByStr(String str){    byte[] bRet = new byte[str.length()/2];    for(int i=0;i< str.length()/2;i++){      Integer itg =new Integer(16*getChrInt(str.charAt(2*i)) + getChrInt(str.charAt(2*i+1)));      bRet[i] = itg.byteValue();    }     return bRet;  } /** 计算一个16进制字符的10进制值 输入：0-F */ private int getChrInt(char chr){   int iRet=0;   if(chr=="0".charAt(0)) iRet = 0;   if(chr=="1".charAt(0)) iRet = 1;   if(chr=="2".charAt(0)) iRet = 2;   if(chr=="3".charAt(0)) iRet = 3;   if(chr=="4".charAt(0)) iRet = 4;   if(chr=="5".charAt(0)) iRet = 5;   if(chr=="6".charAt(0)) iRet = 6;   if(chr=="7".charAt(0)) iRet = 7;   if(chr=="8".charAt(0)) iRet = 8;   if(chr=="9".charAt(0)) iRet = 9;   if(chr=="A".charAt(0)) iRet = 10;   if(chr=="B".charAt(0)) iRet = 11;   if(chr=="C".charAt(0)) iRet = 12;   if(chr=="D".charAt(0)) iRet = 13;   if(chr=="E".charAt(0)) iRet = 14;   if(chr=="F".charAt(0)) iRet = 15;     return iRet;   } } 
 
 
 
 
 
 
 
/** 文件选择组件。 */ class FilePanel extends JPanel{   FilePanel(String str){    JLabel label = new JLabel(str);    JTextField fileText = new JTextField(35);    JButton chooseButton = new JButton("浏览...");    this.add(label);    this.add(fileText);    this.add(chooseButton);    clickAction ca = new clickAction(this);    chooseButton.addActionListener(ca); } public String getFileName(){ JTextField jtf = (JTextField)this.getComponent(1); return jtf.getText(); } private class clickAction implements ActionListener{   clickAction(Component c){    cmpt = c;   }   public void actionPerformed(ActionEvent event){     JFileChooser chooser = new JFileChooser();     chooser.setCurrentDirectory(new File("."));     int ret = chooser.showOpenDialog(cmpt);     if(ret==JFileChooser.APPROVE_OPTION){        JPanel jp = (JPanel)cmpt;        JTextField jtf = (JTextField)jp.getComponent(1);        jtf.setText(chooser.getSelectedFile().getPath());      }   }   private Component cmpt;  } } /** 密码生成组件。 */ class KeyPanel extends JPanel{   KeyPanel(String str){     JLabel label = new JLabel(str);     JTextField fileText = new JTextField(35);     JButton chooseButton = new JButton("随机产生");     this.add(label);     this.add(fileText);     this.add(chooseButton);     clickAction ca = new clickAction(this);     chooseButton.addActionListener(ca); } //返回生成的密码（48个字符长度） public String getKey(){   JTextField jtf = (JTextField)this.getComponent(1);   return jtf.getText(); } private class clickAction implements ActionListener{   clickAction(Component c){    cmpt = c;   } public void actionPerformed(ActionEvent event){  try{    KeyGenerator kg = KeyGenerator.getInstance("DES");    kg.init(56);    Key ke = kg.generateKey();    byte[] bytK1 = ke.getEncoded();    ke = kg.generateKey();    byte[] bytK2 = ke.getEncoded();    ke = kg.generateKey();    byte[] bytK3 = ke.getEncoded();    JPanel jp = (JPanel)cmpt;    JTextField jtf = (JTextField)jp.getComponent(1);    jtf.setText(getByteStr(bytK1)+getByteStr(bytK2)+getByteStr(bytK3));  }catch(Exception e){     e.printStackTrace();   } } private String getByteStr(byte[] byt){   String strRet = "";   for(int i=0;i< byt.length;i++){    //System.out.println(byt[i]);    strRet += getHexValue((byt[i]&240)/16);    strRet += getHexValue(byt[i]&15);   }   return strRet; } private String getHexValue(int s){    String sRet=null;    switch (s){     case 0: sRet = "0";break;     case 1: sRet = "1";break;     case 2: sRet = "2";break;     case 3: sRet = "3";break;     case 4: sRet = "4";break;     case 5: sRet = "5";break;     case 6: sRet = "6";break;     case 7: sRet = "7";break;     case 8: sRet = "8";break;     case 9: sRet = "9";break;     case 10: sRet = "A";break;     case 11: sRet = "B";break;     case 12: sRet = "C";break;     case 13: sRet = "D";break;     case 14: sRet = "E";break;     case 15: sRet = "F";  }    return sRet; }   private Component cmpt;  } } 程序运行图：

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