Using request instance concurrently
Typical Exception Messages
Request.setAttribute() has thrown a NullPointerExceptionjava.lang.NullPointerException1 frames hiddenorg.apache.catalina.connector.Request.setAttribute25Web pages
RequestFacade.setAttribute() has thrown a NullPointerExceptionjava.lang.NullPointerException4 frames hiddenorg.apache.catalina.connector.RequestFacade.setAttribute7Web pages
This problem occurs when the request instance being accessed from the wrong request thread (i.e. two concurrent requests A and B, it was possible for thread B to access the request object from thread A, which is evidently wrong).