Question

我有一个独立的项目来编写测试用例;问题是我无法模拟HttpServletRequest，因为在我的servlet中有类似getServletContext()的调用，因为测试用例是从外部servlet容器运行的。它总会返回一个错误，说'＆34;没有找到上下文＆＃34;。这只是servlet容器的一个依赖项;可能有数百个。例如，initialContext.lookup()也取决于容器。

在这种情况下，如何使用Mockito编写测试用例？请不要询问错误信息;它更像是一个逻辑问题，而不是技术问题。

在互联网上寻找教程让我想知道我是否做了严重的错误。似乎没有人在遇到过这个问题之前......如果没有在servlet中调用HttpServletRequest，你怎么能模拟getServletContext()？我的意思是认真的，它有多罕见？

Answer 1

您有一个使用ServletContext的servlet实现，例如

public class SomeServlet extends HttpServlet{

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        ServletContext servletContext = getServletContext();
        Object attribute = servletContext.getAttribute("test");
        System.out.println(attribute.toString());
   }
}

在这种情况下，您有2个选项来测试doGet方法

使用powermock的partitial mocking仅模拟getServletContext方法。

@RunWith(PowerMockRunner.class)
public class SomeServletTest {

    @Test
    public void onGet() throws ServletException, IOException{
        SomeServlet someServlet = PowerMock.createPartialMock(SomeServlet.class, "getServletContext");   
        ServletContext servletContext = PowerMock.createNiceMock(ServletContext.class);
        HttpServletRequest httpServletRequest = PowerMock.createNiceMock(HttpServletRequest.class);
        HttpServletResponse httpServletResponse = PowerMock.createNiceMock(HttpServletResponse.class);

        someServlet.getServletContext();
        PowerMock.expectLastCall().andReturn(servletContext);

        servletContext.getAttribute("test");
        PowerMock.expectLastCall().andReturn("hello");

        PowerMock.replay(someServlet, servletContext, httpServletRequest, httpServletResponse);

        someServlet.doGet(httpServletRequest, httpServletResponse);
    }
}

或更简单的方法是覆盖getServletContext方法。在这种情况下，您不需要powermock。你可以使用easymock来做到这一点。 e.g。

public class SomeServletTest {

    @Test
    public void onGet() throws ServletException, IOException{
        HttpServletRequest httpServletRequest = EasyMock.createNiceMock(HttpServletRequest.class);
        HttpServletResponse httpServletResponse = EasyMock.createNiceMock(HttpServletResponse.class);
        final ServletContext servletContext = EasyMock.createNiceMock(ServletContext.class);
        SomeServlet someServlet = new SomeServlet(){
            public ServletContext getServletContext() {
                return servletContext; // return the mock
            }
        };

        EasyMock.expect(servletContext.getAttribute("test")).andReturn("hello");
        EasyMock.replay(servletContext, httpServletRequest, httpServletResponse);

        someServlet.doGet(httpServletRequest, httpServletResponse);
    }
}

可以有100个。像initialContext.lookup（）也依赖于容器。

在这种情况下，您可以创建一个InitialContext模拟并使用它。如果您的代码创建了新的InitialContext，例如

public void someMethod(){
    InitialContext context = new InitialContext();
    context.lookup(....);
}

你可以简单地将InitialContext实例化提取到一个受保护的方法，你可以在测试中覆盖它，就像我上面用ServletContext

所示

public void someMethod(){
    InitialContext context = createInitialContext();
    context.lookup(....);
}

protected InitialContext createInitialContext(){
    return new InitialContext(); // can be overridden by a subclass 
                                 // and therefore by tests as well to
                                 // return a mock
}

如果您不想或不能以这种方式修改代码，那么您可以Powermock使用intercept the constructor。

修改

你可以发布你的Mockito代码吗？这将是一种乐趣，因为这些方法的命名方式不同。

@Test public void onGet() throws ServletException, IOException { HttpServletRequest httpServletRequest = Mockito.mock(HttpServletRequest.class); HttpServletResponse httpServletResponse = Mockito.mock(HttpServletResponse.class); final ServletContext servletContext = Mockito.mock(ServletContext.class); SomeServlet someServlet = new SomeServlet(){ public ServletContext getServletContext() { return servletContext; // return the mock } }; Mockito.doReturn("hello").when(servletContext).getAttribute("test"); someServlet.doGet(httpServletRequest, httpServletResponse); }

如何模拟servletContext而不是Servlet或HttpServletRequest？

1 个答案: