在HttpServletRequest和HttpServletResponse上进行JUnit控制器测试

Question

我有这个功能，我想添加测试，但不知道如何填写HttpServletRequest和HttpServletResponse部分。

public void convertXlsToPdf(HttpServletDtoRequest httpServletDtoRequest) throws Exception {
    HttpServletRequest request = httpServletDtoRequest.getRequest();
    HttpServletResponse response = httpServletDtoRequest.getResponse();

    byte[] result =
        documentService.convertBinaryExcelToPdf(IOUtils.toByteArray(request.getInputStream()));
    ServletOutputStream servletOutputStream = response.getOutputStream();

    response.setContentType("application/pdf");
    response.setHeader("Content-Disposition",
        "attachment; filename=fpdf" + System.currentTimeMillis() + ".pdf");
    response.setContentLength(result.length);

    servletOutputStream.write(result, 0, result.length);
    servletOutputStream.flush();
    servletOutputStream.close();
}

我尝试了类似的事情，但它失败并返回了IllegalStateException。

@Test
public void convertXlsToPdf_Test() throws Exception {
    MockHttpServletRequest request = new MockHttpServletRequest();
    MockHttpServletResponse response = new MockHttpServletResponse();

    HttpServletDtoRequest httpServletDtoRequest = new HttpServletDtoRequest();
    httpServletDtoRequest.setRequest(request);
    httpServletDtoRequest.setResponse(response);

    Gson gson = new GsonBuilder().create(); //--> ERROR HERE
    String json = gson.toJson(httpServletDtoRequest);

    this.mockMvc.perform(
        MockMvcRequestBuilders.get("PATH_TO_CLIENT")
            .accept(MediaType.APPLICATION_JSON).contentType(MediaType.APPLICATION_JSON)
            .content(json)).andExpect(status().isOk());

    verify(this.service).convertBinaryExcelToPdf(
        IOUtils.toByteArray(httpServletDtoRequest.getRequest().getInputStream()));
}

例外是：

引起：com.g

oogle.gson.CircularReferenceException: circular reference error
        at com.google.gson.JsonSerializationVisitor.start(JsonSerializationVisitor.java:61)
        at com.google.gson.JsonSerializationVisitor.findAndInvokeCustomSerializer(JsonSerializationVisitor.java:182)
        at com.google.gson.JsonSerializationVisitor.visitFieldUsingCustomHandler(JsonSerializationVisitor.java:204)
        ... 72 more

怎么做？感谢。