首先，对用户输入的password进行MD5转换，然后，对用户输入的Data进行des加密，最后进行base64转换为密文； 解密，对用户输入的password进行MD5转换，然后，对用户输入的Data进行base64解密，最后进行des解密为明文； 现在提供这样一个帮助类，进行类似操作！

package httpVisit.action;     import javax.crypto.Cipher;  import javax.crypto.SecretKey;  import javax.crypto.SecretKeyFactory;  import javax.crypto.spec.DESKeySpec;  import javax.crypto.spec.IvParameterSpec;     import sun.misc.BASE64Decoder;  import sun.misc.BASE64Encoder;     /**   * @author：Heweipo   * @version 1.00   *    */  public class DesCoderUtil {         private static byte[] keys = { 1, -1, 1, -1, 1, -1, 1, -1 };         private static String key = "leagsoft";         public static String getKey() {          return key;      }         public static void setKey(String key) {          DesCoderUtil.key = key;      }         /**       *        * <p>       * 对password进行MD5加密       * @param source       * @return        * @return byte[]           * author: Heweipo       */      public static byte[] getMD5(byte[] source) {          byte tmp[] = null;          try {              java.security.MessageDigest md = java.security.MessageDigest                      .getInstance("MD5");              md.update(source);              tmp = md.digest();          } catch (Exception e) {              e.printStackTrace();          }          return tmp;      }         /**       *        * <p>       * 采用JDK内置类进行真正的加密操作       * @param byteS       * @param password       * @return        * @return byte[]           * author: Heweipo       */      private static byte[] encryptByte(byte[] byteS, byte password[]) {          byte[] byteFina = null;          try {// 初始化加密/解密工具              Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");              DESKeySpec desKeySpec = new DESKeySpec(password);              SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");              SecretKey secretKey = keyFactory.generateSecret(desKeySpec);              IvParameterSpec iv = new IvParameterSpec(keys);              cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);              byteFina = cipher.doFinal(byteS);          } catch (Exception e) {              throw new RuntimeException(e);          }          return byteFina;      }         /**       *        * <p>       * 采用JDK对应的内置类进行解密操作       * @param byteS       * @param password       * @return        * @return byte[]           * author: Heweipo       */      private static byte[] decryptByte(byte[] byteS, byte password[]) {          byte[] byteFina = null;          try {// 初始化加密/解密工具              Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");              DESKeySpec desKeySpec = new DESKeySpec(password);              SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");              SecretKey secretKey = keyFactory.generateSecret(desKeySpec);              IvParameterSpec iv = new IvParameterSpec(keys);              cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);              byteFina = cipher.doFinal(byteS);          } catch (Exception e) {              throw new RuntimeException(e);          }          return byteFina;      }         /**       *        * <p>       * Des加密strMing，然后base64转换       * @param strMing       * @param md5key       * @return        * @return String           * author: Heweipo       */      public static String encryptStr(String strMing, byte md5key[]) {          byte[] byteMi = null;          byte[] byteMing = null;          String strMi = "";          try {              byteMing = strMing.getBytes("utf-8");              byteMi = encryptByte(byteMing, md5key);              BASE64Encoder base64Encoder = new BASE64Encoder();              strMi = base64Encoder.encode(byteMi);          } catch (Exception e) {              throw new RuntimeException(e);          } finally {              byteMing = null;              byteMi = null;          }          return strMi;      }         /**       *        * <p>       * Base64转换strMi,然后进行des解密       * @param strMi       * @param md5key       * @return        * @return String           * author: Heweipo       */      public static String decryptStr(String strMi, byte md5key[]) {          byte[] byteMing = null;          String strMing = "";          try {              BASE64Decoder decoder = new BASE64Decoder();              byteMing = decoder.decodeBuffer(strMi);              byteMing = decryptByte(byteMing, md5key);              strMing = new String(byteMing);          } catch (Exception e) {              throw new RuntimeException(e);          } finally {              byteMing = null;          }          return strMing;      }             public static void main(String[] args) {                     String[] keys = {"leagsoft","leagsoftpo","leagsoftiu","leagsoftyy","leagsoftew","leagsoftmm"};          for(String key : keys){              String data = "我是learn_more，who are you?";              try{                  System.out.println(DesCoderUtil.encryptStr(data, DesCoderUtil.getMD5(key.getBytes("utf-8"))));                  System.out.println("--------------");                  System.out.println(DesCoderUtil.decryptStr(DesCoderUtil.encryptStr(data, DesCoderUtil.getMD5(key.getBytes("utf-8"))),                           DesCoderUtil.getMD5(key.getBytes("utf-8"))));              }catch(Exception e){                  e.printStackTrace();              }          }      }     }