Java单元测试Powermockito和Mockito使用代码示例

作者:袖梨 2022-06-29

本篇文章小编给大家分享一下Java单元测试Powermockito和Mockito使用代码示例,文章代码介绍的很详细,小编觉得挺不错的,现在分享给大家供大家参考,有需要的小伙伴们可以来看看。

依赖引入


    org.mockito
    mockito-core
    2.8.9
    test


    org.powermock
    powermock-module-junit4
    1.7.4
    test


    org.powermock
    powermock-api-mockito2
    1.7.4
    test

PowerMockito的使用

Mockito、EasyMock、JMock等比较流行Mock框架有个共同的缺点,都不能mock静态、final、私有方法等,而PowerMock可以完美解决以上框架的不足,接下来让我们看看无所不能的PowerMock是如何解决上述问题,我们先从一个实例来看,下面的代码是需要单测的类,被测类中既有对Spring Bean的调用,同时又包含对Redis的静态读取,另外还有getInstance()单例类的使用,现在,我们一一来mock上述的外部类。

被单测类(主要测试queryStudentScoreByKeyword方法)

@Component
public class StudentService {

    @Resource
    private StudentDao studentDao;

    public List queryStudentScoreByKeyword(String name) {
        System.out.println("invoke StudentService.queryStudentScoreByKeyword ...");

        List cacheList = RedisUtils.getArray(name, StudentBo.class);
        if (CollectionUtils.isNotEmpty(cacheList)) {
            return cacheList;
        }
        String keyword = processKeyword(name);
        List students = studentDao.queryStudentByKeyWord(keyword);
        List ids = students.stream().map(Student::getId).collect(Collectors.toList());
        List personList = SchoolManageProxy.getInstance().queryPerson(ids);

        List studentBos = CommonUtils.toBo(personList, students);
        // 高亮结果
        highlightResult(studentBos, name);
        // 缓存到Redis
        RedisUtils.setArray(name, studentBos, 10 * 60);
        return studentBos;
    }

    private String processKeyword(String name) {
        System.out.println("invoke StudentService.processKeyword ...");
        String newName = name;
        // do somethings
        return newName;
    }

    private void highlightResult(List result, String name) {
        System.out.println("invoke StudentService.highlightResult ...");
        // do keyword highlight
    }

}

单测类

@RunWith(PowerMockRunner.class)
@PrepareForTest({SchoolManageProxy.class, RedisUtils.class, StudentService.class})
// @PowerMockIgnore({"javax.management.*", "javax.net.ssl.*"})
@SuppressStaticInitializationFor({"cn.ganzhiqiang.ares.unittest.SchoolManageProxy"})
public class StudentServiceTest {

    @Mock
    private StudentDao mockStudentDao;

    @InjectMocks
    private StudentService studentServiceUnderTest;

    @Before
    public void setUp() {
        initMocks(this);
    }

    @Test
    public void testQueryStudentScoreByKeyword() throws Exception {
        studentServiceUnderTest = PowerMockito.spy(studentServiceUnderTest);
        PowerMockito.mockStatic(RedisUtils.class);
        PowerMockito.mockStatic(SchoolManageProxy.class);

        // mock单例调用
        SchoolManageProxy mockSchoolManageProxy = PowerMockito.mock(SchoolManageProxy.class);
        PowerMockito.when(SchoolManageProxy.getInstance()).thenReturn(mockSchoolManageProxy);
        when(mockSchoolManageProxy.queryPerson(anyList())).thenReturn(Collections.emptyList());

        // mock掉对Redis的静态调用
        PowerMockito.when(RedisUtils.getArray(eq("tom"), eq(StudentBo.class))).thenReturn(Collections.emptyList());
        // 显示的mock掉静态的void的方法(可以不mock)
        PowerMockito.doNothing().when(RedisUtils.class, "setArray", anyString(), anyList(), anyInt());

        // mock私有方法processKeyword
        PowerMockito.doReturn("tom").when(studentServiceUnderTest, "processKeyword", anyString());

        // 跳过私有方法highlightResult的执行
        PowerMockito.suppress(PowerMockito.method(StudentService.class, "highlightResult"));

        // 使用Mockito来mock服务的调用
        when(mockStudentDao.queryStudentByKeyWord(anyString())).thenReturn(Collections.emptyList());

        // Run the test
        final List result = studentServiceUnderTest.queryStudentScoreByKeyword("tom");

    }
}

使用mockito来mock实例

首选我们先用Mockito来mock对Spring Bean的调用,Mockito.mock可以mock一个实例,我们这里选用@Mock注解,效果是一样的。

// 使用Mockito来mock服务的调用 
when(mockStudentDao.queryStudentByKeyWord(anyString())).thenReturn(Collections.emptyList());

mock对Redis的静态调用

接下来我们使用PowerMock来mock对静态方法的调用,注意需要将RedisUtils类,加入@PrepareForTest注解中,我们既mock了getArray方法,也mock了setArray方法,其实setArray不需要mock这里显式的mock了

PowerMockito.mockStatic(RedisUtils.class);
// mock掉对Redis的静态调用
PowerMockito.when(RedisUtils.getArray(eq("tom"), eq(StudentBo.class))).thenReturn(Collections.emptyList());
// 显式的mock掉静态的void的方法(可以不mock)
PowerMockito.doNothing().when(RedisUtils.class, "setArray", anyString(), anyList(), anyInt());

mock单例类

mock单例类相对来说复杂一点,逻辑上先用Powermock mock出单例类,然后再给单例类的getInstance方法打桩,返回之前mock,再对mock类实际调用的方法打桩即可,代码如下

PowerMockito.mockStatic(SchoolManageProxy.class);
// Powermock mock出单例类
SchoolManageProxy mockSchoolManageProxy = PowerMockito.mock(SchoolManageProxy.class);
// 给单例类的getInstance方法打桩

PowerMockito.when(SchoolManageProxy.getInstance()).thenReturn(mockSchoolManageProxy);
// 对mock类queryPerson的方法打桩
when(mockSchoolManageProxy.queryPerson(anyList())).thenReturn(Collections.emptyList());

mock私有方法

可以看到queryStudentScoreByKeyword方法调用了该类的私有方法processKeyword,如果该方法耗时过长,使用powermock也可以mock该私有方法,需要注意的studentServiceUnderTest需要用spy()来mock

// mock 实例
// spy的标准是:如果不打桩,默认执行真实的方法,如果打桩则返回桩实现。
studentServiceUnderTest = PowerMockito.spy(studentServiceUnderTest);
// mock私有方法processKeyword
// doReturn(...) when(...)不做真实调用,但是when(...) thenReturn(...)还是会真实调用原方法,只是返回了指定的结果
PowerMockito.doReturn("tom").when(studentServiceUnderTest, "processKeyword", anyString());

PowerMock跳过方法执行

使用PowerMock也可以跳过私有方法的执行

// 跳过私有方法highlightResult的执行
PowerMockito.suppress(PowerMockito.method(StudentService.class, "highlightResult"));

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