問題描述

我的代碼中只有參數(shù)化的構(gòu)造函數(shù)，我需要通過它進(jìn)行注入.

I have only parameterized constructor in my code and i need to inject through it.

我想監(jiān)視參數(shù)化構(gòu)造函數(shù)以注入模擬對象作為我的 junit 的依賴項(xiàng).

I want to spy parameterized constructor to inject mock object as dependency for my junit.

public RegDao(){
 //original object instantiation here
Notification ....
EntryService .....
}

public RegDao(Notification notification , EntryService entry) {
 // initialize here
}

we have something like below : 
RegDao dao = Mockito.spy(RegDao.class);

但是我們有什么東西可以讓我在構(gòu)造函數(shù)中注入模擬對象并監(jiān)視它嗎?

But do we have something that i can inject mocked object in the Constructor and spy it?.

推薦答案

您可以通過在 junit 中使用參數(shù)化構(gòu)造函數(shù)實(shí)例化您的主類，然后從中創(chuàng)建一個(gè)間諜來做到這一點(diǎn).

You can do that by instantiating your main class with parametrized constructor in your junit and then creating a spy from it.

假設(shè)您的主類是A.其中 B 和 C 是它的依賴項(xiàng)

Let's suppose your main class is A. Where B and C are its dependencies

public class A {

    private B b;

    private C c;

    public A(B b,C c)
    {
        this.b=b;
        this.c=c;
    }

    void method() {
        System.out.println("A's method called");
        b.method();
        c.method();
        System.out.println(method2());

    }

    protected int method2() {
        return 10;
    }
}

然后您可以使用下面的參數(shù)化類為此編寫 junit

Then you can write junit for this using your parametrized class as below

@RunWith(MockitoJUnitRunner.class)
public class ATest {

    A a;

    @Mock
    B b;

    @Mock
    C c;

    @Test
    public void test() {
        a=new A(b, c);
        A spyA=Mockito.spy(a);

        doReturn(20).when(spyA).method2();

        spyA.method();
    }
}

測試類的輸出

A's method called
20

1. 這里 B 和 C 是您使用參數(shù)化構(gòu)造函數(shù)注入到您的類 A 中的模擬對象.
2. 然后我們創(chuàng)建了一個(gè)名為 spyA 的 A 的 spy.
3. 我們通過修改類 A 中受保護(hù)方法 method2 的返回值來檢查 spy 是否真的有效，這不可能如果 spyA 不是 A 的實(shí)際 spy.

1. Here B and C are mocked object that you injected in your class A using parametrized constructor.
2. Then we created a spy of A called spyA.
3. We checked if spy is really working by modifying the return value of a protected method method2 in class A which could not have been possible if spyA was not an actual spy of A.

這篇關(guān)于為什么我們不能使用 Mockito 為參數(shù)化構(gòu)造函數(shù)創(chuàng)建間諜的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網(wǎng)！