接收多部分文件请求的415不支持的媒体类型

Question

我想使用javax和spring框架（不是spring boot）编写一个API，该API应该接受发布请求并将文件上传到其中控制器在tomcat服务器中运行的服务器。问题是我拥有所有必需的代码，但是当我调用API时，出现415不支持的类型错误。所需的代码定义如下：

@POST
@Path("file/{productName}")
public String uploadFile(@RequestParam("file") MultipartFile file, @PathParam("productName") String productName) throws IOException {
    File folderPath = new File("/Users/homeDirectory/Desktop/FileUploadTest");
    FileOutputStream fout = new FileOutputStream(folderPath+"/"+ file.getOriginalFilename());
    fout.write(file.getBytes());
    fout.close();
    return "Response";

我还有另一个客户端（子模块）正在使用Unirest调用上传终结点。文件类型可以是CSV或PNG

File f = new File("/Users/homeDirectory/Desktop/aggregateReport.csv");
    HttpResponse<String> response = Unirest.post("http://localhost:8080/report-rest/report/v1/file/test123")
            .field("file", f).asString();

并且在服务器端，我看到以下错误：

Apr 04, 2020 10:13:33 PM org.apache.cxf.jaxrs.utils.JAXRSUtils logMessageHandlerProblem
SEVERE: No message body reader has been found for class org.springframework.web.multipart.MultipartFile, ContentType: multipart/form-data;boundary=1MbhkGkO-__me1XVpPXpsLEWcSMn4ltIz4
Apr 04, 2020 10:13:33 PM org.apache.cxf.jaxrs.impl.WebApplicationExceptionMapper toResponse
WARNING: javax.ws.rs.WebApplicationException: HTTP 415 Unsupported Media Type
	at org.apache.cxf.jaxrs.utils.JAXRSUtils.readFromMessageBody(JAXRSUtils.java:1339)
	at org.apache.cxf.jaxrs.utils.JAXRSUtils.processParameter(JAXRSUtils.java:824)
	at org.apache.cxf.jaxrs.utils.JAXRSUtils.processParameters(JAXRSUtils.java:788)
	at org.apache.cxf.jaxrs.interceptor.JAXRSInInterceptor.processRequest(JAXRSInInterceptor.java:212)
	at org.apache.cxf.jaxrs.interceptor.JAXRSInInterceptor.handleMessage(JAXRSInInterceptor.java:77)
	at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:308)
	at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121)
	at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:254)
	at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:234)
	at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:208)
	at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:160)
	at org.apache.cxf.transport.servlet.CXFNonSpringServlet.invoke(CXFNonSpringServlet.java:180)
	at org.apache.cxf.transport.servlet.AbstractHTTPServlet.handleRequest(AbstractHTTPServlet.java:299)
	at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doPost(AbstractHTTPServlet.java:218)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
	at org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:274)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1468)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)

Answer 1

@POST
@Path("file/{productName}")
public Response uploadFile(MultipartBody multipartBody, @PathParam("productName") String productName) {
    List<Attachment> attachments = multipartBody.getAllAttachments();
    List<DataHandler> dataHandlers = attachments.stream().map(Attachment::getDataHandler).collect(Collectors.toList());
    dataHandlers.forEach(dataHandler -> {
        String fileName = dataHandler.getName();
        try {
            InputStream fileContentStream = dataHandler.getInputStream();
            if (Objects.isNull(fileContentStream)) {
                LOGGER.error("Null Stream received in request");
            } else {
                String directoryPath = fileUtil.createDirectoryToSaveFiles(uploadProperties.getSourceDirectoryLocation(), productName);
                File fileToWrite = fileUtil.createFileToWrite(directoryPath + File.separator + fileName);
                fileUtil.writeContentInFile(fileContentStream, fileToWrite);
            }
        } catch (Exception e) {
            throw new RuntimeException("Something went wrong while writing to file "+ e.getMessage());
        }
    });
    return Response.ok("Sample String").build();
}