単体テスト:mock外部依存オブジェクトをビジネスクラスに注入

public class ConvertController {
	@Resource
	private ConvertServiceImpl convertservice;
	public  APIResult convert() throws Exception {
		APIResult result = null;
		result = convertservice.getConvertResult();
		return result;
	}
}
public class ConvertServiceImpl implements ConvertService {
	public APIResult getConvertResult() {
		
	}
}

public class ConvertControllerTest {
    
    //mock 
	private ConvertController controller;
    // mock 
	private ConvertServiceImpl convertservice;

    // test 
	@Before
	public void setUp() throws Exception {

		controller = new ConvertController();
		convertservice = Mockito.mock(ConvertServiceImpl.class); //  Mock 
		Whitebox.setInternalState(controller, "convertservice", convertservice); //  
	}
	@Test
	public void testconvert() throws Exception {
        // 
		APIResult api = new APIResult(0, "error");
        // convertservice getConvertResult() api
		Mockito.when(convertservice.getConvertResult().thenReturn(api);
        // 
		APIResult result = controller.convert();
        // 
		Assert.assertEquals("{\"code\":0,\"errMsg\":\"error\"}", result.toString());
	}
}