Java单测void类型的方法详解

@Override
 public void updateRuleName(Long ruleId, String newRuleName, Long ucId) {
 Assert.notNull(ruleId, "规则ID不能为Null");
 Assert.notNull(newRuleName, "规则名称不能为Null");
 Assert.notNull(ucId, "操作人的UCID不能为Null");
 
 String cleanNewRuleName = StringUtils.trim(newRuleName);
 if (StringUtils.isBlank(cleanNewRuleName)) {
  throw new IllegalArgumentException("新的规则名称不能为空");
 }
 
 // 查询规则对象
 Rule rule = queryRuleById(ruleId);
 if (null == rule) {
  throw new IllegalDataException("没有查到该规则");
 }
 
 rule.setRuleId(ruleId);
 rule.setRuleName(cleanNewRuleName);
 rule.setUpdateUcid(ucId);
 rule.setUpdateTime(new Date());
 
 ruleDao.updateSelective(rule);
 }

 @Test
 public void testUpdateRuleName() {
 Long ruleId = 1L;
 String newRuleName = "newRuleName";
 Long ucId = 123L;
 
 List<Rule> rules = new ArrayList<Rule>();
 Rule rule = new Rule();
 rule.setRuleStatus((byte) DBValueSetting.RULE_STATUS_TAKE_EFFECT);
 rules.add(rule);
 
 // 查询规则对象
 Map<String, Object> params = new HashMap<String, Object>();
 params.put("ruleId", ruleId);
 Mockito.when(ruleDao.queryRulesByCondition(params)).thenReturn(rules);
 
 Mockito.doAnswer(new Answer<Object>() {
  public Object answer(InvocationOnMock invocation) {
  // 断点2：这里随后执行
  Rule rule = (Rule) invocation.getArguments()[0];
  Assert.assertTrue(rule.getRuleName().equals("newRuleName"));
  return null;
  }
 }).when(ruleDao).updateSelective(Mockito.any(Rule.class));
 
 // 断点1：先执行到这里
 ruleService.updateRuleName(ruleId, newRuleName, ucId);
 }

public interface Answer<T> {
 /**
 * @param invocation the invocation on the mock.
 *
 * @return the value to be returned
 *
 * @throws Throwable the throwable to be thrown
 */
 T answer(InvocationOnMock invocation) throws Throwable;
}