import java.security.MessageDigest;  import java.security.NoSuchAlgorithmException;  /*   * MD5 算法  */  public class MD5 {             // 全局数组      private final static String[] strDigits = { "0", "1", "2", "3", "4", "5",              "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };         public MD5() {      }         // 返回形式为数字跟字符串      private static String byteToArrayString(byte bByte) {          int iRet = bByte;          // System.out.println("iRet="+iRet);          if (iRet < 0) {              iRet += 256;          }          int iD1 = iRet / 16;          int iD2 = iRet % 16;          return strDigits[iD1] + strDigits[iD2];      }         // 返回形式只为数字      private static String byteToNum(byte bByte) {          int iRet = bByte;          System.out.println("iRet1=" + iRet);          if (iRet < 0) {              iRet += 256;          }          return String.valueOf(iRet);      }         // 转换字节数组为16进制字串      private static String byteToString(byte[] bByte) {          StringBuffer sBuffer = new StringBuffer();          for (int i = 0; i < bByte.length; i++) {              sBuffer.append(byteToArrayString(bByte[i]));          }          return sBuffer.toString();      }         public static String GetMD5Code(String strObj) {          String resultString = null;          try {              resultString = new String(strObj);              MessageDigest md = MessageDigest.getInstance("MD5");              // md.digest() 该函数返回值为存放哈希值结果的byte数组              resultString = byteToString(md.digest(strObj.getBytes()));          } catch (NoSuchAlgorithmException ex) {              ex.printStackTrace();          }          return resultString;      }         public static void main(String[] args) {          MD5 getMD5 = new MD5();          System.out.println(getMD5.GetMD5Code("000000"));      }  }