@Override
	public int compare(String version1, String version2) {
		if(ObjectUtil.equal(version1, version2)) {
			return 0;
		}
		if (version1 == null && version2 == null) {
			return 0;
		} else if (version1 == null) {// null或""视为最小版本，排在前
			return -1;
		} else if (version2 == null) {
			return 1;
		}

		return CompareUtil.compare(Version.of(version1), Version.of(version2));
	}
@Test
	public void versionComparatorTes6() {
		int compare = VersionComparator.INSTANCE.compare("V0.0.20170102", "V0.0.20170101");
		assertTrue(compare > 0);

		// 自反测试
		compare = VersionComparator.INSTANCE.compare("V0.0.20170101", "V0.0.20170102");
		assertTrue(compare < 0);
	}