無法模擬/窺探 class java.util.Optional

Question

我正在嘗試實現這個 JUnit 代碼：

private BinlistsService binlistsService = Mockito.mock(BinlistsService.class);

@Mock
Optional<BinLists> binList = null;

@BeforeEach
    public void beforeEachTest() throws IOException {

        BinLists binLists = new BinLists();
        binLists.setId(1);
        ....

        binList = Optional.of(binLists);
    }

    @Test
    public void testBinCountryCheckFilterImpl() {

        when(binlistsService.findByName(anyString())).thenReturn(binList);

}

但我得到這個錯誤堆棧：

org.mockito.exceptions.base.MockitoException: 
Cannot mock/spy class java.util.Optional
Mockito cannot mock/spy because :
 - final class
    at org.data

你知道我該如何解決這個問題嗎？

Answer 1

刪除Optional<BinLists>字段上的@Mock 。

Optional的是一個簡單的 class ，您可以輕松地創建和控制它，因此您不需要模擬它。只需在需要時創建一個實際實例，您已經在beforeEachTest()中完成了它：

private BinlistsService binlistsService = Mockito.mock(BinlistsService.class);

Optional<BinLists> binList = null;

@BeforeEach
    public void beforeEachTest() throws IOException {

        BinLists binLists = new BinLists();
        binLists.setId(1);
        ....

        binList = Optional.of(binLists);
    }

    @Test
    public void testBinCountryCheckFilterImpl() {

        when(binlistsService.findByName(anyString())).thenReturn(binList);

}

Answer 2

您不需要模擬class Optional （java 核心 class final ），您需要模擬class BinLists

    @Mock
    BinLists binList = null;

JUnit can`t mock the final class, but if you need this unusual technique of mocking can use PowerMock https://github.com/powermock/powermock