java - 静态实例上的模拟方法

Question

我有一个类:

public class Factory {
   private static final Factory instance = new Factory();
   private Factory() {
   }
   public static Factory getInstance() {
       return instance;
   }
   private Client client = null;

   //To be mocked
   //Failing at this point 
   //Not actually using mocked method
   public Client getClient(Properties properties) {
      //doSomething
      //...
      return client;
   }
}

在另一个类中，上述方法用作:

public class Service {
  protected Client client = null;
  protected void keySetup() {
     //Should be mocked
     client = Factory.getInstance().getClient(properties());

     ...
     ...
  }
}

对于 keySetup() 方法的单元测试，我尝试模拟 Factory.getInstance().getClient(properties()) 但失败了。

我尝试执行以下操作:

@Test
public void testKeySetupTrue(){
    Client client = mock(Client.class); 
    Factory factory = mock(Factory.class);
    ReflectionTestUtils.setField(factory, "client", client);    
    Properties properties = mock(Properties.class);

    Mockito.doReturn(client).when(factory)
    .getClient(properties);

    Service service = new Service();

    service.keySetup();
    ...
    ...
}

当我在 Debug模式下运行时，我看到它实际上正在执行被模拟的 getClient(Properties properties) 。

如何解决这个问题？

Answer 1

static final 不是一个很好的设计。最好注入(inject)依赖项并让框架(spring 或其他)担心控制单例。也就是说，就你而言，使用反射通过模拟工厂设置 Factory 实例 变量。