MultiKeyComparator implements Comparator<MultiKey>, Serializable { public MultiKeyComparator(List<SortCondition> sortConditions) { if (null == sortConditions || sortConditions.isEmpty()) { String msg = "Sort conditions is illegal."; LOG.error(msg); throw new IllegalArgumentException(msg); } this.sortConditions = sortConditions; } MultiKeyComparator(List<SortCondition> sortConditions); @Override int compare(MultiKey first, MultiKey second);  }
@Test public void testMultiKeyComparator() { try { mc = new MultiKeyComparator(null); fail(); } catch (IllegalArgumentException ex) { assertTrue(true); } try { mc = new MultiKeyComparator(sclist); fail(); } catch (IllegalArgumentException ex) { assertTrue(true); } }