上面的例子是很理想化的狀態,但是在實際的開發中,我們需要經常調用一些依賴特定環境的函數或者調用同事寫的代碼,而同事僅提供了接口。這個時候就需要利用Mockito來協助我們完成測試。
當然,你可以選擇easyMock ,jmock等mock工具
在這里直接引用《PowerMock實戰手冊》中的例子
待測類:
public class EmployeeService { private EmployeeDao employeeDao; public EmployeeService(EmployeeDao employeeDao) { this.employeeDao = employeeDao; } }
待測類調用的方法
public class EmployeeDao { public int getTotal() { throw new UnsupportedOperationException(); } }
其中 getTotal 就是一個利用正常辦法無法測試的函數。
測試類:
public class EmployeeServiceTest { @Mock private EmployeeDao employeeDao; EmployeeService employeeService; @BeforeMethod public void init(){ MockitoAnnotations.initMocks(this); employeeService = new EmployeeService(employeeDao); } @Test public void testGetTotalEmployee() { PowerMockito.when(employeeDao.getTotal()).thenReturn(10); int total = employeeService.getTotalEmployee(); assertEquals(10, total); } }
@Mock 是Mockito的標記 與MockitoAnnotations.initMocks(this) 配合使用,等效於
EmployeeDao employeeDao = Mockito.mock(EmployeeDao.class)
如果些對象在測試類反復使用的話,前一種寫法能節省很多代碼
@BeforeMethod 是testNG標記 ,作用是在運行很一個測試方法之前運行此方法
@Test testNG標識,表明此方法是一個測試方法
PowerMockito.when(employeeDao.getTotal()).thenReturn(10);
錄制mock的行為,當調用getTotal方法時,返回10
具體請參照:http://site.mockito.org/mockito/docs/current/org/mockito/Mockito.html
下面是運行結果:
[TestNG] Running: C:\Users\changzhz\AppData\Local\Temp\testng-eclipse--599967477\testng-customsuite.xml PASSED: testGetTotalEmployee =============================================== Default test Tests run: 1, Failures: 0, Skips: 0 =============================================== =============================================== Default suite Total tests run: 1, Failures: 0, Skips: 0 =============================================== [TestNG] Time taken by org.testng.reporters.SuiteHTMLReporter@5f205aa: 49 ms [TestNG] Time taken by org.testng.reporters.JUnitReportReporter@424c0bc4: 8 ms [TestNG] Time taken by org.testng.reporters.jq.Main@2ff5659e: 37 ms [TestNG] Time taken by [FailedReporter passed=0 failed=0 skipped=0]: 1 ms [TestNG] Time taken by org.testng.reporters.EmailableReporter2@1996cd68: 3 ms [TestNG] Time taken by org.testng.reporters.XMLReporter@27ddd392: 5 ms