??在mock方法時(shí)，對(duì)于方法的參數(shù)匹配是有要求的，只有要執(zhí)行的方法的參數(shù)匹配mock方法里面的參數(shù)時(shí)，該mock方法才會(huì)起作用。Powermock提供了很多種參數(shù)匹配的方式，比如，如果需要精確地匹配參數(shù)，可以使用equal方式；如果需要靈活地匹配參數(shù)，可以使用any方式。下面，我們就來簡單地介紹下mock方法時(shí)的參數(shù)匹配。

一、精確匹配

??還是先來看下被測試代碼：

public class EmployeeService {
    public Employee findEmployeeByEmail(String email) {
        throw new UnsupportedOperationException();
    }

    public boolean employeeExists(Employee employee) {
        throw new UnsupportedOperationException();
    }
}
public class EmployeeController {
    private EmployeeService employeeService;

    public EmployeeController(EmployeeService employeeService) {
        this.employeeService = employeeService;
    }

    public Employee findEmployeeByEmail(String email) {
        return employeeService.findEmployeeByEmail(email);
    }

    public boolean isEmployeeEmailAlreadyTaken(String email) {
        return employeeService.employeeExists(new Employee(email));
    }
}

??代碼很直觀，EmployeeController類中定義了兩個(gè)方法，一個(gè)是findEmployeeByEmail，根據(jù)email查詢員工，調(diào)用employeeService.findEmployeeByEmail方法；另一個(gè)方法是isEmployeeEmailAlreadyTaken方法，判斷某個(gè)員工是否存在，調(diào)用employeeService.employeeExists方法。
??
??現(xiàn)在看下測試代碼：

public class EmployeeControllerTest {
    @Test
    public void testFindEmployeeByEmail() {
        EmployeeService employeeService = PowerMockito.mock(EmployeeService.class);
        Employee employee = new Employee();
        PowerMockito.when(employeeService.findEmployeeByEmail(Mockito.eq("123@abc.com"))).thenReturn(employee);

        EmployeeController employeeController = new EmployeeController(employeeService);

        Assert.assertSame(employee, employeeController.findEmployeeByEmail("123@abc.com"));
        Assert.assertNull(employeeController.findEmployeeByEmail("123@dce.com"));
    }
}

??從上述測試方法可以看到，在模擬employeeService.findEmployeeByEmail方法時(shí)使用了eq方法，這個(gè)就是精確匹配模式，執(zhí)行參數(shù)完全匹配該參數(shù)時(shí)，才會(huì)返回employee。

二、模糊匹配

??有時(shí)候，我們想要在匹配參數(shù)時(shí)更靈活些，可以使用模糊匹配?？聪孪旅娴臏y試方法：

public class EmployeeControllerTest {
    @Test
    public void testFindEmployeeByEmail() {
        EmployeeService employeeService = PowerMockito.mock(EmployeeService.class);
        Employee employee = new Employee();
        PowerMockito.when(employeeService.findEmployeeByEmail(Mockito.startsWith("123"))).thenReturn(employee);

        EmployeeController employeeController = new EmployeeController(employeeService);

        Assert.assertSame(employee, employeeController.findEmployeeByEmail("123@abc.com"));
        Assert.assertSame(employee, employeeController.findEmployeeByEmail("123@dce.com"));
        Assert.assertNull(employeeService.findEmployeeByEmail("456@abc.com"));
    }
}

??該例中，使用startWith替換了eq，可以看到當(dāng)參數(shù)為"123@abc.com"和"123@456.com"時(shí)，都返回了employee，而"456@abc.com"則返回了Null?？梢姶藭r(shí)參數(shù)是匹配任何以"123"開頭的字符串，這種用法能夠使得參數(shù)的匹配相對(duì)于eq方式更靈活些。

三、任意匹配

??另外一種參數(shù)匹配，即無論入?yún)⑹鞘裁粗担颊J(rèn)為是匹配的。

public class EmployeeControllerTest {
    @Test
    public void testFindEmployeeByEmail() {
        EmployeeService employeeService = PowerMockito.mock(EmployeeService.class);
        Employee employee = new Employee();
        PowerMockito.when(employeeService.findEmployeeByEmail(Mockito.anyString())).thenReturn(employee);

        EmployeeController employeeController = new EmployeeController(employeeService);

        Assert.assertSame(employee, employeeController.findEmployeeByEmail("123@abc.com"));
        Assert.assertSame(employee, employeeController.findEmployeeByEmail("123@dce.com"));
        Assert.assertSame(employee, employeeService.findEmployeeByEmail("456@abc.com"));
    }
}

??此例中，使用了anyString方式，即無論入?yún)⑹鞘裁醋址挤祷豦mployee。此時(shí)可以看出給定的三個(gè)字符串，都返回了employee。

四、自定義匹配

??除了使用自帶的匹配方式之外，還可以自己定義相應(yīng)的參數(shù)匹配方式。

public class EmployeeControllerTest {
    @Test
    public void testIsEmployeeEmailAlreadyTaken() {
        EmployeeService employeeService = PowerMockito.mock(EmployeeService.class);
        final String email = "123@abc.com";
        PowerMockito.when(employeeService.employeeExists(Mockito.argThat(new ArgumentMatcher<Employee>() {
            @Override
            public boolean matches(Object employee) {
                return ((Employee) employee).getEmail().equals(email);
            }
        }))).thenReturn(true);

        EmployeeController employeeController = new EmployeeController(employeeService);

        Assert.assertTrue(employeeController.isEmployeeEmailAlreadyTaken(email));
    }
}

??這個(gè)例子看上去稍微有點(diǎn)復(fù)雜。從業(yè)務(wù)代碼可以看出，EmployeeController類的方法isEmployeeEmailAlreadyTaken和EmployeeService類的方法參數(shù)并不一樣，但是又有所關(guān)聯(lián)，是使用isEmployeeEmailAlreadyTaken的入?yún)?gòu)造了一個(gè)新的入?yún)ⅰ，F(xiàn)在，我們要想精確匹配入?yún)?，就需要自己?shí)現(xiàn)matcher方法。

??除了上述的一些例子外，Mockito還提供了許多別的參數(shù)匹配的方法，比如any、matches、isNull等等。如何使用這些匹配方式，需要根據(jù)自己的需求來選擇相應(yīng)的模式實(shí)現(xiàn)。另外，上面介紹的參數(shù)匹配同樣適用于Mockito.verify。

??最后，強(qiáng)調(diào)一點(diǎn)，對(duì)于多個(gè)參數(shù)的方法，如果我們其中一個(gè)參數(shù)使用了參數(shù)匹配模式，那么所有的參數(shù)都必須使用參數(shù)匹配模式，下面的例子中的使用方式就是錯(cuò)誤的：

PowerMockito.when(mock.findEmployeeByFirstNameAndLastName("Deep", Mockito.anyString())).thenReturn(null);

??正確的方式為：

PowerMockito.when(mock.findEmployeeByFirstNameAndLastName(Mockito.eq("Deep"), Mockito.anyString())).thenReturn(null);