title: How to check null value from Java Method of Tibco ActiveMatrix
body: <p>I am having a trouble on checking null value from a Java Method component in Tibco ActiveMatrix process. </p>
  
  <p>Basically, I have a Java Method component invoking java to get a billing account, if the return is null, I would like to log the searching criteria - billing account id; otherwise, I will map the object to be XML content...</p>
  
  <p>The problem is while using the following in 'XPath' to check the null object in a transition (Success with condition):</p>
  
  <ul>
  <li>empty($Get-BA-Details/ns5:JavaMethodActivityOutput/MethodReturnValue</li>
  <li>count($Get-BA-Details/ns5:JavaMethodActivityOutput/MethodReturnValue)= 0 </li>
  <li>string-length($Get-BA-Details/ns5:JavaMethodActivityOutput/MethodReturnValue) = 0</li>
  </ul>
  
  <p><em>'$Get-BA-Details' is the Java Method component.</em></p>
  
  <p>they all return 'false', and then try to map the java object to be XML content, which results in error while billing account is not found. </p>
  
  <p>Could anyone shed some lights?</p>
  
  <p>Thanks a lot!</p>