mockStatic：用PowerMock模拟java.lang

Question

我试图用Mockito模拟MBeanServer，但是我的尝试失败了。

@Test 
public void testGetAllCacheProperties() { 
    mockStatic(ManagementFactory.class); 
    MBeanServer server = MBeanServerFactory.newMBeanServer(); 
    ObjectInstance inst = server.registerMBean(new MyBeanService(), ObjectName.getInstance(SERVICE_NAME)); 
    given(ManagementFactory.getPlatformMBeanServer()).willReturn(server); 
} 

我想注入我的模拟到方法通常在jBoss AS 7运行：

@GET 
public Response getAllProperties() { 
    MBeanServer platformMBeanServer = ManagementFactory.getPlatformMBeanServer(); 

但它失败，出现异常：

org.mockito.exceptions.misusing.WrongTypeOfReturnValue: 
JmxMBeanServer cannot be returned by getPlatformMBeanServer() 
getPlatformMBeanServer() should return MBeanServer 

---

更新

当我尝试

PowerMockito.doReturn(server).when(ManagementFactory.class, "getPlatformMBeanServer"); 

我得到异常：

java.lang.LinkageError: loader constraint violation: when resolving method "java.lang.management.ManagementFactory.getPlatformMBeanServer()Ljavax/management/MBeanServer;" the class loader (instance of org/powermock/core/classloader/MockClassLoader) of the current class, my_package_for_test_class.TestClass, and the class loader (instance of <bootloader>) for the method's defining class, java/lang/management/ManagementFactory, have different Class objects for the type javax/management/MBeanServer used in the signature 

Answer 1

没有可能从java.lang包嘲笑静态的，因为PowerMock试图改变咬码和咬java.lang类 明显保护的代码从修改。

有解决办法Johan Haleby。 你必须创建包装类：

public class JmxUtils { 

    public static MBeanServer getPlatformMbeanServer() { 
     return ManagementFactory.getPlatformMBeanServer(); 
    } 
} 

然后测试看起来像这样

@RunWith(PowerMockRunner.class) 
@PrepareForTest(JmxUtils.class) 
public class CacheControllerTest { 
    //.. preconditions 
    given(JmxUtils.getPlatformMbeanServer()).willReturn(server);