JDK17适配Mockito4.9.0后，如何替代@SuppressStaticInitializationFor？

问题背景 #

报错信息：

Cannot instrument class XXX because it or one of its supertypes could not be initialized

因JDK17兼容性问题切换至Mockito 4.9.0后，原@SuppressStaticInitializationFor注解无法使用，但需要阻止部分类的静态初始化逻辑执行，现有测试代码如下：

@RunWith(MockitoJUnitRunner.class)
//@PrepareForTest({NonWorkingDayHelper.class, TaskService.class})
//@SuppressStaticInitializationFor("com.ecquaria.cloud.entity.nonworkingday.NonWorkingDayHelper")
public class TaskManagerTest {

    @Before
    public void setUp(){
        Mockito.mockStatic(NonWorkingDayHelper.class);
        Mockito.mockStatic(TaskService.class);
    }
    @Test
    public void testUpdateSLARemainInDays() throws Exception {
        Mockito.when(NonWorkingDayHelper.isNonWorkingDay(any(Date.class))).thenReturn(false);
        Mockito.when(TaskService.getInstance()).thenReturn(Mockito.mock(TaskService.class));
        TaskManager.updateSLARemainInDays();

    }
}

解决方案 #

在Mockito 4.x中，可通过Mockito.mockStatic()的重载方法结合MockedStaticSettings实现禁用类静态初始化的效果，替代原@SuppressStaticInitializationFor注解：

1. 确保依赖包含mockito-inline #

Mockito 4.x的静态类Mock功能需要依赖mockito-inline模块（默认mockito-core不支持），Maven依赖配置如下：

<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-inline</artifactId>
    <version>4.9.0</version>
    <scope>test</scope>
</dependency>

2. 修改测试代码的静态Mock逻辑 #

创建MockedStatic实例时，通过withSettings().withoutStaticInitializer()设置禁用目标类的静态初始化：

@RunWith(MockitoJUnitRunner.class)
public class TaskManagerTest {

    private MockedStatic<NonWorkingDayHelper> nonWorkingDayHelperMock;
    private MockedStatic<TaskService> taskServiceMock;

    @Before
    public void setUp(){
        // 禁用NonWorkingDayHelper的静态初始化
        nonWorkingDayHelperMock = Mockito.mockStatic(NonWorkingDayHelper.class, 
            Mockito.withSettings().withoutStaticInitializer());
        // 禁用TaskService的静态初始化
        taskServiceMock = Mockito.mockStatic(TaskService.class, 
            Mockito.withSettings().withoutStaticInitializer());
    }

    @After
    public void tearDown(){
        // 关闭静态Mock，避免影响其他测试
        nonWorkingDayHelperMock.close();
        taskServiceMock.close();
    }

    @Test
    public void testUpdateSLARemainInDays() throws Exception {
        nonWorkingDayHelperMock.when(() -> NonWorkingDayHelper.isNonWorkingDay(any(Date.class)))
            .thenReturn(false);
        taskServiceMock.when(TaskService::getInstance)
            .thenReturn(Mockito.mock(TaskService.class));
        TaskManager.updateSLARemainInDays();
    }
}

关键说明 #

• withoutStaticInitializer()会完全阻止目标类的静态代码块执行及静态字段初始化，与原@SuppressStaticInitializationFor注解效果一致
• 静态Mock实例需要在测试结束后调用close()方法释放，避免对其他测试用例产生干扰

内容的提问来源于stack exchange，提问作者Pan Yichun