Android中的MD5加密

 private String getMD5Str(String str) {       
      MessageDigest messageDigest = null;       
     
      try {       
          messageDigest = MessageDigest.getInstance("MD5");       
     
          messageDigest.reset();       
     
          messageDigest.update(str.getBytes("UTF-8"));       
      } catch (NoSuchAlgorithmException e) {       
          System.out.println("NoSuchAlgorithmException caught!");       
          System.exit(-1);       
      } catch (UnsupportedEncodingException e) {       
          e.printStackTrace();       
      }       
     
      byte[] byteArray = messageDigest.digest();       
     
      StringBuffer md5StrBuff = new StringBuffer();       
        
      for (int i = 0; i < byteArray.length; i++) {                   
          if (Integer.toHexString(0xFF & byteArray[i]).length() == 1)       
              md5StrBuff.append("0").append(Integer.toHexString(0xFF & byteArray[i]));       
          else       
              md5StrBuff.append(Integer.toHexString(0xFF & byteArray[i]));       
      }       
    //16位加密，从第9位到25位  
      return md5StrBuff.substring(8, 24).toString().toUpperCase();      
  }  

API

*   MessageDigest digester = MessageDigest.getInstance("MD5");
  *   byte[] bytes = new byte[8192];
  *   int byteCount;
  *   while ((byteCount = in.read(bytes)) > 0) {
  *     digester.update(bytes, 0, byteCount);
  *   }
  *   byte[] digest = digester.digest();
  * </pre>