java中3des加密解密示例

import java.security.Security;
  import javax.crypto.Cipher;
  import javax.crypto.SecretKey;
  import javax.crypto.spec.SecretKeySpec;
  /*字符串 DESede(3DES) 加密*/
  public class ThreeDes {
  /**
  * @param args在java中调用sun公司提供的3DES加密解密算法时，需要使
  * 用到$JAVA_HOME/jre/lib/目录下如下的4个jar包：
  *jce.jar
  *security/US_export_policy.jar
  *security/local_policy.jar
  *ext/sunjce_provider.jar
  */
  private static final String Algorithm ="DESede"; //定义加密算法,可用 DES,DESede,Blowfish
  //keybyte为加密密钥，长度为24字节
  //src为被加密的数据缓冲区（源）
  public static byte[] encryptMode(byte[] keybyte,byte[] src){
  try {
  //生成密钥
  SecretKey deskey = new SecretKeySpec(keybyte, Algorithm);
  //加密
  Cipher c1 = Cipher.getInstance(Algorithm);
  c1.init(Cipher.ENCRYPT_MODE, deskey);
  return c1.doFinal(src);//在单一方面的加密或解密
  } catch (java.security.NoSuchAlgorithmException e1) {
  // TODO: handle exception
  e1.printStackTrace();
  }catch(javax.crypto.NoSuchPaddingException e2){
  e2.printStackTrace();
  }catch(java.lang.Exception e3){
  e3.printStackTrace();
  }
  return null;
  }
  //keybyte为加密密钥，长度为24字节
  //src为加密后的缓冲区
  public static byte[] decryptMode(byte[] keybyte,byte[] src){
  try {
  //生成密钥
  SecretKey deskey = new SecretKeySpec(keybyte, Algorithm);
  //解密
  Cipher c1 = Cipher.getInstance(Algorithm);
  c1.init(Cipher.DECRYPT_MODE, deskey);
  return c1.doFinal(src);
  } catch (java.security.NoSuchAlgorithmException e1) {
  // TODO: handle exception
  e1.printStackTrace();
  }catch(javax.crypto.NoSuchPaddingException e2){
  e2.printStackTrace();
  }catch(java.lang.Exception e3){
  e3.printStackTrace();
  }
  return null;
  }
  //转换成十六进制字符串
  public static String byte2Hex(byte[] b){
  String hs="";
  String stmp="";
  for(int n=0; n<b.length; n++){
  stmp = (java.lang.Integer.toHexString(b[n]& 0XFF));
  if(stmp.length()==1){
  hs = hs + "0" + stmp;
  }else{
  hs = hs + stmp;
  }
  if(n<b.length-1)hs=hs+":";
  }
  return hs.toUpperCase();
  }
  public static void main(String[] args) {
  // TODO Auto-generated method stub
  //添加新安全算法,如果用JCE就要把它添加进去
  Security.addProvider(new com.sun.crypto.provider.SunJCE());
  final byte[] keyBytes = {0x11, 0x22, 0x4F, 0x58,
  (byte)0x88, 0x10, 0x40, 0x38, 0x28, 0x25, 0x79,0x51,
  (byte)0xCB,
  (byte)0xDD, 0x55, 0x66, 0x77, 0x29, 0x74,
  (byte)0x98, 0x30, 0x40, 0x36,
  (byte)0xE2
  }; //24字节的密钥
  String szSrc = "This is a 3DES test. 测试";
  System.out.println("加密前的字符串:" + szSrc);
  byte[] encoded = encryptMode(keyBytes,szSrc.getBytes());
  System.out.println("加密后的字符串:" + new String(encoded));
  byte[] srcBytes = decryptMode(keyBytes,encoded);
  System.out.println("解密后的字符串:" + (new String(srcBytes)));
  }
  }