Expecting custom exception instead of null pointer exception while junit testing
<p>I have method in java class :</p>

<pre><code>@Context
UriInfo uriInfo;
public void processRequest(@QueryParam ("userId") @DefaultValue("") String userId)
{
     String baseURI = uriInfo.getBaseUri().toString();
     if(userId == null)
     {
         //UserIdNotFoundException is my custom exception which extends Exceptition
         throw new UserIdNotFoundException();
     }
 }
</code></pre>

<p>When I'm junit testing the above method expecting for UserIdNotFoundException when userId parameter is Null, I get the following Assertion error : <code>expected  an instance of UserIdNotFoundException but &lt;java.lang.NullPointerException&gt; is java.lang.NullPointerException</code>. </p>

<pre><code>@Test
public void testProcessRequest_throws_UserIdNotFoundException()
{
     expectedException.expect(UserIdNotFoundException.class);
     processRequest(null);
}
</code></pre>

<p>My custom exception class :</p>

<pre><code>public class UserIdNotFoundException extends Exception
{

     public UserIdNotFoundException()
     {

     }

     public UserIdNotFoundException(String message)
     {
          super(message);
     }
}
</code></pre>