MockMvcRequestBuilders.asyncDispatch 提供空的 HTTP 响应和 contentType答案

【问题标题】：MockMvcRequestBuilders.asyncDispatch providing an empty HTTP Response and contentTypeMockMvcRequestBuilders.asyncDispatch 提供空的 HTTP 响应和 contentType
【发布时间】：2019-06-22 01:12:04
【问题描述】：

我有一个单元测试，在使用 Spring 4.3 将方法转换为返回 StreamingResponseBody 之后，我试图检查正在发出的异步请求的响应。

测试方法如下：

final MockMvc mockMvc = MockMvcBuilders.webAppContextSetup(wac)
     .apply(SecurityMockMvcConfigurers.springSecurity())
     .build();

MvcResult mvcResult1 = mockMvc.perform(
   get("/reports/generic/100?FIELD1=&FIELD3=").headers(STANDARD_HEADERS.get()))
  .andExpect(status().isOk())
  .andExpect(request().asyncStarted())
  .andReturn();

mvcResult1.getAsyncResult();

mockMvc.perform(asyncDispatch(mvcResult1))
                    .andExpect(status().isOk())
                    .andExpect(content().contentType("text/csv"))
                    .andExpect(content().string("Test Data" + System.lineSeparator() + "FIELD1=" + System.lineSeparator() + "FIELD3=" + System.lineSeparator()))

它调用的方法如下：

public StreamingResponseBody streamReport(@PathVariable("type") @NotNull String type, @PathVariable("id") @NotNull Long id, ReportConfiguration config, HttpServletResponse response) throws Exception {


    ReportServiceHandler handler = reportHandlerFactory.getHandler(type);
    final String reportFilename = handler.getReportFileName(id, reportConfiguration);

    response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename=" + reportFilename);
    response.setContentType("text/csv");

    return new StreamingResponseBody() {

        @Override
        public void writeTo(OutputStream outputStream) throws IOException {

            try {
                response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename=" + reportFilename);
                response.setContentType("text/csv");
                ServletOutputStream out = (ServletOutputStream) outputStream;
                handler.generateReport(out, id, reportConfiguration);
                out.flush();
            } catch ( Exception e ) {
                response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "inline");
                response.setContentType("");
                throw new IOException(e);
            }
        }
    };
}

调试显示原始请求中包含来自异步的响应，但异步响应对象（在 mvcResult1 内）没有在 期间被复制asyncDispatch 所以 contextType 和 content 字符串都是空的。

这里是否遗漏了处理异步 mvcResult 以便可以断言内容的测试配置？

【问题讨论】：

标签： java spring spring-mvc spring-test spring-test-mvc

【解决方案1】：

我在这方面做得相当成功。以下是我的不同做法：

    return new StreamingResponseBody() {

    @Override
    public void writeTo(OutputStream outputStream) throws IOException {

        try {
            ... same
            out.flush();
        } catch ( Exception e ) {
            ... your error handling
        } finally {
            // Try to close the stream
            try {
                if (out != null) {
                    out.close();
                }
            } catch (Throwable t) {
                // not much we can do
            }
        }
    }
};

现在，我的测试与您的测试平行。阅读您的代码时，我不确定您为什么调用 perform() 两次。对我来说只需要一次。

//Same
final MockMvc mockMvc = MockMvcBuilders.webAppContextSetup(wac)
   .apply(SecurityMockMvcConfigurers.springSecurity())
   .build();

// Same
MvcResult mvcResult1 = mockMvc.perform(
get(....))
  .andExpect(status().isOk())
  .andExpect(request().asyncStarted())
  .andReturn();
    
mvcResult1.getAsyncResult();

// From this point on, I have complete response,
// if it's not bugging you to place the entire file in memory
String thisIsYourFileContent = mvcResult1.getResponse().getContentAsString();

// Go on asserting the content of the file...

希望这对某人有所帮助。

【讨论】：