在java中模拟类变量值的单元测试问题

Question

我有一个类，它有一个初始化为

public class MyClass{

    private BusinessObject businessObject = BusinessObjectGenerator.getBusinessObject();

    public MyClass(){

    }

    public Object myMethodToTest(){
    return businessObject.getObject();
    }
}

现在，我正在尝试单元测试myMethodToTest，我想发送一个模拟对象来代替businessObject。我使用mockito进行模拟，使用spy(new MyClass())进行部分模拟，但在模拟get businessObject的调用时遇到困难。 1.是否可以模拟对businessObject的调用？如果是，怎么做？ 2.在编写单元测试时，如何重构此代码以提供帮助。任何指向这一点的资源都将大有裨益

谢谢

Answer 1

要正确重构此代码，您需要：

private BusinessObject businessObject;

public void setBusinessObject(BusinessObject instance) {
    businessObject = instance;
}

private BusinessObject getBusinessObject() {
    if (businessObject == null) {
        // represents existing implementation in original code sample
        businessObject = BusinessObjectGenerator.getBusinessObject();
    }
    return businessObject;
}

/* rest of your code */

现在，您可以在测试站点将模拟注入到类中

我建议使用依赖注入和Guice这样的框架来实现这一点。这是值得你花时间的