title: How to decode with MessageDigest , Base64
body: <p>I am currently encoding a password.  I have to decode the password.  Here is the code to encode.  I am trying to get the original password compare it.  I have researched about MessageDigest that says it is a one-way method.  Not sure how to get the original message.  We have a decode method but it isn't giving me the original password - Base64.decode.</p>
  
  <pre><code> public static synchronized String getMD5_Base64(String input) {
          if (!isInited) {
              isInited = true;
              try {
                  digest = MessageDigest.getInstance("MD5");
              } catch (Exception ex) {
              }
          }
          if (digest == null)
              return input;
  
          // now everything is ok, go ahead
          try {
              digest.update(input.getBytes("UTF-8"));
          } catch (java.io.UnsupportedEncodingException ex) {
          }
          byte[] rawData = digest.digest();
          byte[] encoded = Base64.encode(rawData);
          String retValue = new String(encoded);
          return retValue;
      }
  }
  </code></pre>