powermock - 如何使用 PowerMock 模拟非静态方法

Question

我正在尝试模拟我的测试方法的内部方法调用

我的类(class)看起来像这样

public class App {
public Student getStudent() {
    MyDAO dao = new MyDAO();
    return dao.getStudentDetails();//getStudentDetails is a public 
                                  //non-static method in the DAO class
}

当我为 getStudent() 方法编写 junit 时，PowerMock 中是否有一种方法可以模拟该行

dao.getStudentDetails();

或者让 App 类在 junit 执行期间使用模拟 dao 对象而不是连接到数据库的实际 dao 调用？

Answer 1

您可以使用 whenNew()来自 PowerMock 的方法(见 https://github.com/powermock/powermock/wiki/Mockito#how-to-mock-construction-of-new-objects)

完整的测试用例

import org.junit.*;
import org.junit.runner.RunWith;
import org.mockito.Mockito;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

import static org.junit.Assert.*;

@RunWith(PowerMockRunner.class)
@PrepareForTest(App.class)
public class AppTest {
    @Test
    public void testGetStudent() throws Exception {
        App app = new App();
        MyDAO mockDao = Mockito.mock(MyDAO.class);
        Student mockStudent = Mockito.mock(Student.class);

        PowerMockito.whenNew(MyDAO.class).withNoArguments().thenReturn(mockDao);
        Mockito.when(mockDao.getStudentDetails()).thenReturn(mockStudent);
        Mockito.when(mockStudent.getName()).thenReturn("mock");

        assertEquals("mock", app.getStudent().getName());
    }
}

我为这个测试用例制作了一个简单的 Student 类:

public class Student {
    private String name;
    public Student() {
        name = "real";
    }
    public String getName() {
        return name;
    }
}