title: Add message to existing NullPointerException
body: <p>I'm catching different kind of Exceptions in my method. </p>
  
  <p>If the exception is a <code>NullPointerException</code>, I'd like to add a message to the existing exception. </p>
  
  <p>Is there a way to add a message to an existing NullPointerException? I can't just create a new Exception, because I need the stacktrace etc. </p>
  
  <p>My idea was to just create a new Exception like that:</p>
  
  <pre><code>new Exception("the message", myNullPointer);
  </code></pre>
  
  <p>But then, the output isn't as I need it, because that way, my stacktrace looks like that:</p>
  
  <pre><code>java.lang.Exception:
  ...bla
  ...bla
  </code></pre>
  
  <p>But I need it to keep the NullPointerException like that:</p>
  
  <pre><code>java.lang.NullPointerException:
  ...bla
  ...bla
  </code></pre>
  
  <p>Also it's important to say that I haven't access to the part where the initial NullPointer is created. So I can't add a message at start.</p>
  
  <p><strong>Edit:</strong> I know I should avoid NPEs. But I have to influence about the thrown NPE. So I have to react.</p>