public void testClearRemovesMDCValue() { ThreadContext log4jThreadContext = ThreadContext.newMDCEnabledContext(); Hashtable mdcContext = MDC.getContext(); assertTrue(mdcContext == null || mdcContext.isEmpty()); final String testKey = "painter"; log4jThreadContext.put(testKey, 7); mdcContext = MDC.getContext(); assertEquals(1, mdcContext.size()); mdcContext.clear(); assertEquals(0, mdcContext.size()); log4jThreadContext.clear(); assertNull("get() after clear should return null", log4jThreadContext.get(testKey)); } }