Mockito when语句Maven构建触发Method.getParameterTypes()空指针，Eclipse正常

问题背景 #

维护的单元测试在Eclipse中运行无异常，但使用Maven构建时抛出空指针异常，当前使用Mockito核心版本v5.5.0。

出错代码 #

测试方法 #

@Test
public void testfilterFeatureEnabled() throws Exception {
    when(featureToggle.havingValue()).thenReturn("stuff");
    when(activationStrategy.isApplicable(any(Feature.class))).thenReturn(true); // 54行，异常触发处
    when(activationStrategy.havingValue(any(Feature.class), anyString())).thenReturn(true);
    
    featureToggleFilter.filter(reqContext);
    
    verify(reqContext, never()).abortWith(any(Response.class));
}

测试类Mock定义 #

@ExtendWith(MockitoExtension.class)
public class FeatureToggleFilterTest {

    @InjectMocks
    private FeatureToggleFilter featureToggleFilter;

    @Mock
    private FeatureToggle featureToggle;

    @Mock
    private ActivationStrategy  activationStrategy;

    @Mock
    private ContainerRequestContext reqContext;
}

Maven构建堆栈信息 #

java.lang.NullPointerException
    at java.base/java.lang.reflect.Method.getParameterTypes(Method.java:311)
    at org.mockito.internal.creation.DelegatingMethod.<init>(DelegatingMethod.java:20)
    at org.mockito.internal.invocation.DefaultInvocationFactory.createMockitoMethod(DefaultInvocationFactory.java:81)
    at org.mockito.internal.invocation.DefaultInvocationFactory.createInvocation(DefaultInvocationFactory.java:60)
    at org.mockito.internal.creation.bytebuddy.MockMethodInterceptor.doIntercept(MockMethodInterceptor.java:83)
    at org.mockito.internal.creation.bytebuddy.MockMethodInterceptor.doIntercept(MockMethodInterceptor.java:56)
    at org.mockito.internal.creation.bytebuddy.MockMethodInterceptor$DispatcherDefaultingToRealMethod.interceptAbstract(MockMethodInterceptor.java:161)
    at com.att.idp.featuretoggle.core.ActivationStrategy$MockitoMock$4gFdat1K.isApplicable(Unknown Source)
    at com.att.idp.featuretoggle.web.jaxrs.FeatureToggleFilterTest.testfilterFeatureEnabled(FeatureToggleFilterTest.java:54)

异常触发于测试代码第54行，排查发现是Method.getParameterTypes()调用时抛出NPE，推测关联的Method实例被Mock导致。

解决方法 #

在Maven Surefire插件配置中添加进程隔离相关属性，强制测试在独立进程中运行即可解决问题。示例配置如下：

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>3.2.5</version> <!-- 使用对应版本的Surefire插件 -->
            <configuration>
                <forkCount>1</forkCount>
                <reuseForks>true</reuseForks>
            </configuration>
        </plugin>
    </plugins>
</build>

内容的提问来源于stack exchange，提问作者David M. Karr