如何用 Headers 模拟 HttpServletRequest？

Question

我正在使用 Mockito 和 JUnit 来测试应用程序。我需要在模拟时向 HttpServletRequest 添加标头。这是我第一次使用模拟概念来测试应用程序。我们如何在使用这个模拟概念时为请求对象设置标头？

申请代码

@Produces({ MediaType.APPLICATION_JSON })
@Path("/devices")
public class DvrRestService {
    private static final Logger logger = LoggerFactory.getLogger(DvrRestService.class);

    private DvrMiddleService dvrMiddleService;

    @Inject
    public DvrRestService(DvrMiddleService dvrMiddleService) {
        this.dvrMiddleService = dvrMiddleService;
    }

    @GET
    @Path("/{deviceId}/metadata")
    public Response getDeviceMetadata(@Context HttpServletRequest request, @PathParam("deviceId") String deviceId,
        @RequiredSession final Session session) {

        try {
            public static String[] REQUEST_HEADERS = { "if-none-match" };
            List<String> requiredHeaders = Lists.newArrayList(REQUEST_HEADERS);
            Map<String, String> headers = new HashMap<String, String>();

            Enumeration<String> headerNames = request.getHeaderNames();
            while (headerNames.hasMoreElements()) { // here gettting NullPointerException

                String headerName = headerNames.nextElement();
                if (requiredHeaders.contains(headerName.toLowerCase())) {
                    String value = request.getHeader(headerName);
                    if (value != null) {
                        headers.put(headerName, value);
                        System.out.println("headerName: " + headerName + ", Value: " + value);
                    }
                }
            }
            DvrResponse response = dvrMiddleService.getDeviceMetadata(deviceId.toUpperCase(), getHeaders(request));
            return processResponse(response.statusCode, response.getResponse(), DeviceMetadataResponse.class,
                response.getHeaders());
        } catch (Exception e) {
            return processErrorResponse(e, new DeviceMetadataResponse(), logger);
        }

    }
}

测试

public class DvrRestServiceTest {

    static DvrMiddleService dms;
    static HttpServletRequest request;
    static Session session;
    static DvrRestService drs;
    public static final String DeviceId = "000004D42070";
    @BeforeClass
    public static void init(){
        dms = mock(DvrMiddleService.class);
        request = mock(HttpServletRequest.class);
        session = mock(Session.class);
        drs = new DvrRestService(dms);
    }
    @Test
    public void getDeviceMetadataTest(){
        Response rs = drs.getDeviceMetadata(request, DeviceId, session);
        assertEquals(Response.Status.OK, rs.getStatus());
    }
}

原文由 Sat 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

作为主体的起点和演示，您可以从以下代码片段开始。

 // define the headers you want to be returned
Map<String, String> headers = new HashMap<>();
headers.put(null, "HTTP/1.1 200 OK");
headers.put("Content-Type", "text/html");

// create an Enumeration over the header keys
Enumeration<String> headerNames = Collections.enumeration(headers.keySet());

// mock HttpServletRequest
HttpServletRequest request = mock(HttpServletRequest.class);
// mock the returned value of request.getHeaderNames()
when(request.getHeaderNames()).thenReturn(headerNames);

System.out.println("demonstrate output of request.getHeaderNames()");
while (headerNames.hasMoreElements()) {
    System.out.println("header name: " + headerNames.nextElement());
}

// mock the returned value of request.getHeader(String name)
doAnswer(new Answer<String>() {
    @Override
    public String answer(InvocationOnMock invocation) throws Throwable {
        Object[] args = invocation.getArguments();
        return headers.get((String) args[0]);
    }
}).when(request).getHeader("Content-Type");

System.out.println("demonstrate output of request.getHeader(String name)");
String headerName = "Content-Type";
System.out.printf("header name: [%s]   value: [%s]%n",
        headerName, request.getHeader(headerName));
}

输出

demonstrate output of request.getHeaderNames()
header name: null
header name: Content-Type

demonstrate output of request.getHeader(String name)
header name: [Content-Type]   value: [text/html]

原文由 SubOptimal 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 2

对于 HttpServletRequest ，我建议使用功能齐全的模拟类型，而不是直接使用 Mockito 模拟来模拟它。 spring-test 库有 MockHttpServletRequest 用于此目的：

 @BeforeClass
public static void init(){
    // ...

    MockHttpServletRequest mockRequest = new MockHttpServletRequest();
    mockRequest.addHeader("Content-Type", "text/html");
    mockRequest.addHeader("if-none-match", "*");
    mockRequest.addHeader("customHeader", "customValue");

    this.request = mockRequest;
}

基本原理

HttpServletRequest 是一个复杂的接口，有超过 20 个方法，它们之间有明确定义的相互作用。使用库中的 HttpServletRequest 的全功能模拟类型简化了模拟，无需仔细模拟您正在使用的方法。

这种方法的一个优点是它在面对未来使用类上的其他方法获取相同信息的重构时更具弹性。在 HttpServletRequest 中检索“if-none-match”标头的情况下，我看到可以合法地用于检索标头的三种不同方法： getHeader(String name) ， getHeaders(String name) 和 getHeaderNames() 。此外， getHeader 和 getHeaders 的参数不区分大小写（“if-none-match”、“If-None-Match”等返回相同的结果。 ), 所以任何可能的参数大小写都是正确的。很可能通过直接模拟来支持这一点，尽管它涉及额外的样板代码，使测试复杂化并使其不那么明显。

来自 spring-test 库的 MockHttpServletRequest 类模拟此接口，并允许通过简单的 API 设置标头和其他值。虽然该库是为测试 Spring 应用程序而设计的，但 MockHttpServletRequest 类独立于任何 Spring 特定的功能，即使应用程序不使用 Spring，它也应该完全可用。

原文由 M. Justin 发布，翻译遵循 CC BY-SA 4.0 许可协议