Mockito未返回预期值

Question

我正在使用JUnit和Mockito库来测试我的应用程序。问题是，当我在代码下面执行时，值在运行时没有返回空列表，并且测试失败。理想情况下，当GetEmployee()get执行时，它应该返回空列表

public class Check_Test extends TestCase
{
    public void testMyCheck()
    {
        Check checkObj = new Check();
        EmployeeFactory employeeFactoryMock = Mockito.mock(EmployeeFactory.class);
        Mockito.doReturn(Collections.EMPTY_LIST).when(employeeFactoryMock).getEmployee();
        String str = checkObj.myCheck();
        assertEquals("", str);
    }
}

public class Check
{
    public String myCheck()
    {
        List<Employee> employee = EmployeeFactory.getInstance().getEmployee();
        if (employee.isEmpty())
        {
            return ""; //Line No. 8 returning empty but, control is not coming here
        }
        else
        {
            return "NotEmpty"; // The control is always coming here ????
        }
    }
}

我热切期待着支持。有没有人能帮我一下，如何通过这个测试用例？？？。如何通过Mockito使第8行的控件通过测试用例？？？

请假设，下面两个类没有真实的代码，我们只有二进制文件作为JAR文件，我们不能修改下面的代码....我附上这个是为了我们的理解...

public class EmployeeFactory
{

    private EmployeeFactory()
    {

    }

    public static EmployeeFactory getInstance()
    {
        return EmployeeFactoryHelper.INSTANCE;

    }

    private static class EmployeeFactoryHelper
    {
        public static final EmployeeFactory INSTANCE = new EmployeeFactory();
    }

    private static List<Employee> employees = null;

    static
    {
        employees = Arrays.asList(
                                  new Employee("Manish", "Kumar", true, 60),
                                  new Employee("Siva", "Attla", true, 42),
                                  new Employee("Anand", "Manivel", false, 51),
                                  new Employee("Madhavi", "Govind", true, 45),
                                  new Employee("Janani", "Chidambaram", true, 45),
                                  new Employee("Mannu", "Krishna", false, 39),
                                  new Employee("Karthika", "Hosamane", false, 39)
                          );
    }

    public List<Employee> getEmployee()
    {
        return employees;

    }

}


public class Employee
{

    private String firstName;
    private String lastName;
    private boolean workStatus;
    private int age;

    public Employee(String firstName, String lastName, boolean workStatus, int age)
    {
        super();
        this.firstName = firstName;
        this.lastName = lastName;
        this.workStatus = workStatus;
        this.age = age;
    }

    public String getFirstName()
    {
        return firstName;
    }

    public void setFirstName(String firstName)
    {
        this.firstName = firstName;
    }

    public String getLastName()
    {
        return lastName;
    }

    public void setLastName(String lastName)
    {
        this.lastName = lastName;
    }

    public boolean isWorkStatus()
    {
        return workStatus;
    }

    public void setWorkStatus(boolean workStatus)
    {
        this.workStatus = workStatus;
    }

    public int getAge()
    {
        return age;
    }

    public void setAge(int age)
    {
        this.age = age;
    }

    @Override
    public String toString()
    {
        return "Employee [firstName=" + firstName + ", lastName=" + lastName + ", workStatus=" + workStatus + ", age=" + age + "]";
    }

}

Answer 1

不是调用静态工厂方法，而是注入工厂（可能在构造函数中）并在类中使用它。这样，您就可以解耦类，并且您将能够在测试阶段注入一个模拟实现，而不是真正的实现。小例子：

class EmployeeFactory{
  public Employee getEmployee(){...}
}

class Check{
  private EmployeeFactory factory;
  public Check(EmployeeFactory factory){ this.factory = factory;

  public String myCheck()
  {
    List<Employee> employee = factory.getEmployee();
}

在模拟中：

public class Check_Test extends TestCase
{
    public void testMyCheck()
    {
        EmployeeFactory employeeFactoryMock = Mockito.mock(EmployeeFactory.class);
        Check checkObj = new Check(employeeFactoryMock);
        Mockito.doReturn(Collections.EMPTY_LIST).when(employeeFactoryMock).getEmployee();
        String str = checkObj.myCheck();
        assertEquals("", str);
    }
}