Spring测试静态方法打桩-PowerMockito及SpringBootTest结合使用

灰太狼 2022-05-24 08:27 91阅读 0赞

Mockito无法对静态方法进行Mock，如果需要Mock静态方法，需要使用到PowerMockito。

# 1. Maven依赖 #

<dependency>
        <groupId>org.powermock</groupId>
        <artifactId>powermock-api-mockito</artifactId>
        <version>1.7.1</version>
    </dependency>
    
    <dependency>
        <groupId>org.powermock</groupId>
        <artifactId>powermock-module-junit4</artifactId>
        <version>1.7.1</version>
    </dependency>

# 2. 单元测试 #

单元测试时，需要使用PowerMockRunner及PrepareForTest两个注解：

@RunWith(PowerMockRunner.class)
    @PrepareForTest({SysCache.class})
    public class ModelAssistantServiceUTTest { 
        private ModelAssistantService modelAssistantService;
    
        private ModelAssistantDao modelAssistantDao;
    
        private String tenantId;
        private String deviceTypeId;
    
        @Before
        public void before() throws NoSuchFieldException, IllegalAccessException {
            modelAssistantService = new ModelAssistantServiceImpl();
            modelAssistantDao = MockUtil.mockField(ModelAssistantServiceImpl.class,
                    modelAssistantService, "modelAssistantDao", ModelAssistantDao.class);
    
            this.tenantId = "158";
            this.deviceTypeId = "3000";
    
            // SysCache打桩
            PowerMockito.mockStatic(SysCache.class);
            PowerMockito.when(SysCache.getTargetDbCache(BDDMockito.anyLong(), BDDMockito.anyString(), BDDMockito.any()))
                    .thenReturn(new TargetDB());
        }
    }

如果不使用PrepareForTest，将会报以下错误：

... not prepared for test.

而使用PrepareForTest注解时，必须要使用PowerMockRunner才会生效！

# 3 与SpringBootTest一起使用 #

SpringBootTest必须要使用SpringRunner才能生效；但RunWith没有办法指定多个，可以通过PowerMockRunnerDelegate来解决这个问题：

@RunWith(PowerMockRunner.class)
    @PowerMockRunnerDelegate(SpringRunner.class)
    @PrepareForTest(HttpRequest.class)
    @SpringBootTest

单单添加了以上四个注解还是不够，在执行的时候会报以下错误：

java.lang.LinkageError: loader constraint violation: loader (instance of org/powermock/core/classloader/MockClassLoader) previously initiated loading for a different type with name "javax/management/MBeanServer"

此时需要通过PowerMockIgnore注解来解决：

@PowerMockIgnore( {
       "javax.management.*"})

再次执行，发现又报以下错误：

Caused by: java.security.NoSuchAlgorithmException: class configured for SSLContext: sun.security.ssl.SSLContextImpl$TLSContext not a SSLContext

需要在PowerMockIgnore再添加一个忽略项：

@PowerMockIgnore( {
       "javax.management.*", "javax.net.ssl.*"})

因此，最终测试类上的注解如下：

@RunWith(PowerMockRunner.class)
    @PowerMockRunnerDelegate(SpringRunner.class)
    @PowerMockIgnore( {
       "javax.management.*", "javax.net.ssl.*"})
    @PrepareForTest(HttpRequest.class)
    @SpringBootTest

这样之后测试类终于可以成功启动了。