Question

我正在使用Spring 3和RestTemplate。我基本上有两个应用程序，其中一个必须将值发布到另一个应用程序。通过休息模板。

当要发布的值是字符串时，它的工作完美，但是当我必须发布混合和复杂的参数（如MultipartFiles）时，我会得到转换器异常。

例如，我有这个：

App1 - PostController：

@RequestMapping(method = RequestMethod.POST)
public String processSubmit(@ModelAttribute UploadDTO pUploadDTO, 
        BindingResult pResult) throws URISyntaxException, IOException {
    URI uri = new URI("http://localhost:8080/app2/file/receiver");

    MultiValueMap<String, Object> mvm = new LinkedMultiValueMap<String, Object>();
    mvm.add("param1", "TestParameter");
    mvm.add("file", pUploadDTO.getFile()); // MultipartFile

    Map result = restTemplate.postForObject(uri, mvm, Map.class);
    return "redirect:postupload";
}

另一方面......我有另一个从App1接收参数的Web应用程序（App2）。

App2 - ReceiverController

@RequestMapping(value = "/receiver", method = { RequestMethod.POST })
public String processUploadFile(
        @RequestParam(value = "param1") String param1,
        @RequestParam(value = "file") MultipartFile file) {

    if (file == null) {
        System.out.println("Shit!... is null");
    } else {
        System.out.println("Yes!... work done!");
    }
    return "redirect:postupload";
}

我的application-context.xml：

<bean id="restTemplate" class="org.springframework.web.client.RestTemplate">
    <property name="messageConverters">
        <list>
            <bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter" />
            <bean class="org.springframework.http.converter.FormHttpMessageConverter" />
            <bean class="org.springframework.http.converter.StringHttpMessageConverter" />
            <bean class="org.springframework.http.converter.xml.SourceHttpMessageConverter" />
        </list>
    </property>
</bean>

<bean id="multipartResolver"  
    class="org.springframework.web.multipart.commons.CommonsMultipartResolver">  
    <property name="maxUploadSize">  
        <value>104857600</value>  
    </property>  
    <property name="maxInMemorySize">  
        <value>4096</value>  
    </property>      
</bean>

这是我在执行RestTemplate的postForObject时获得的异常堆栈...

org.springframework.http.converter.HttpMessageNotWritableException: Could not write request: no suitable HttpMessageConverter found for request type [org.springframework.web.multipart.commons.CommonsMultipartFile]
at org.springframework.http.converter.FormHttpMessageConverter.writePart(FormHttpMessageConverter.java:292)
at org.springframework.http.converter.FormHttpMessageConverter.writeParts(FormHttpMessageConverter.java:252)
at org.springframework.http.converter.FormHttpMessageConverter.writeMultipart(FormHttpMessageConverter.java:242)
at org.springframework.http.converter.FormHttpMessageConverter.write(FormHttpMessageConverter.java:194)
at org.springframework.http.converter.FormHttpMessageConverter.write(FormHttpMessageConverter.java:1)
at org.springframework.web.client.RestTemplate$HttpEntityRequestCallback.doWithRequest(RestTemplate.java:588)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:436)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:415)
at org.springframework.web.client.RestTemplate.postForObject(RestTemplate.java:294)
at com.yoostar.admintool.web.UploadTestController.create(UploadTestController.java:86)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:175)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:421)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:409)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:774)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:560)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:619)

所以我的问题是：

是否可以使用POST通过RestTemplate发送MultipartFile？
我是否需要使用某些特定的转换器来发送此类对象？我的意思是在我的配置中使用一些 MultipartFileHttpMessageConverter ？

Answer 1

无需使用需要磁盘上文件的FileSystemResource即可解决此问题的方法是使用ByteArrayResource，这样您就可以在帖子中发送一个字节数组（此代码适用于Spring 3.2.3）： / p>

MultiValueMap<String, Object> map = new LinkedMultiValueMap<String, Object>();
final String filename="somefile.txt";
map.add("name", filename);
map.add("filename", filename);
ByteArrayResource contentsAsResource = new ByteArrayResource(content.getBytes("UTF-8")){
            @Override
            public String getFilename(){
                return filename;
            }
        };
map.add("file", contentsAsResource);
String result = restTemplate.postForObject(urlForFacade, map, String.class);

我覆盖了ByteArrayResource的getFilename，因为如果我不这样做，我会得到一个空指针异常（显然它取决于 java activation .jar 是否在类路径上，如果是，则它将使用文件名来尝试确定内容类型）

Answer 2

前几天我也遇到了同样的问题。谷歌搜索让我和其他几个地方，但没有人给出这个问题的解决方案。我最终将上传的文件（MultiPartFile）保存为tmp文件，然后使用FileSystemResource通过RestTemplate上传它。这是我使用的代码，

String tempFileName = "/tmp/" + multiFile.getOriginalFileName();
FileOutputStream fo = new FileOutputStream(tempFileName);

fo.write(asset.getBytes());    
fo.close();   

parts.add("file", new FileSystemResource(tempFileName));    
String response = restTemplate.postForObject(uploadUrl, parts, String.class, authToken, path);   


//clean-up    
File f = new File(tempFileName);    
f.delete();

我仍然在寻找一个更优雅的解决方案来解决这个问题。

Answer 3

MultiValueMap<String, Object> parts = new LinkedMultiValueMap<String, Object>();
parts.add("name 1", "value 1");
parts.add("name 2", "value 2+1");
parts.add("name 2", "value 2+2");
Resource logo = new ClassPathResource("/org/springframework/http/converter/logo.jpg");
parts.add("logo", logo);
Source xml = new StreamSource(new StringReader("<root><child/></root>"));
parts.add("xml", xml);

template.postForLocation("http://example.com/multipart", parts);

Answer 4

我最近在这个问题上挣扎了3天。客户端如何发送请求可能不是原因，服务器可能未配置为处理多部分请求。这是我必须做的才能让它发挥作用：

pom.xml - 添加了commons-fileupload依赖项（如果您没有使用maven等依赖项管理，请下载并将jar添加到项目中）

<dependency>
  <groupId>commons-fileupload</groupId>
  <artifactId>commons-fileupload</artifactId>
  <version>${commons-version}</version>
</dependency>

web.xml - 添加多部分过滤器和映射

<filter>
  <filter-name>multipartFilter</filter-name>
  <filter-class>org.springframework.web.multipart.support.MultipartFilter</filter-class>
</filter>
<filter-mapping>
  <filter-name>multipartFilter</filter-name>
  <url-pattern>/springrest/*</url-pattern>
</filter-mapping>

app-context.xml - 添加多部分解析器

<beans:bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <beans:property name="maxUploadSize">
        <beans:value>10000000</beans:value>
    </beans:property>
</beans:bean>

您的控制器

@RequestMapping(value=Constants.REQUEST_MAPPING_ADD_IMAGE, method = RequestMethod.POST, produces = { "application/json"})
public @ResponseBody boolean saveStationImage(
        @RequestParam(value = Constants.MONGO_STATION_PROFILE_IMAGE_FILE) MultipartFile file,
        @RequestParam(value = Constants.MONGO_STATION_PROFILE_IMAGE_URI) String imageUri, 
        @RequestParam(value = Constants.MONGO_STATION_PROFILE_IMAGE_TYPE) String imageType, 
        @RequestParam(value = Constants.MONGO_FIELD_STATION_ID) String stationId) {
    // Do something with file
    // Return results
}

您的客户

public static Boolean updateStationImage(StationImage stationImage) {
    if(stationImage == null) {
        Log.w(TAG + ":updateStationImage", "Station Image object is null, returning.");
        return null;
    }

    Log.d(TAG, "Uploading: " + stationImage.getImageUri());
    try {
        RestTemplate restTemplate = new RestTemplate();
        FormHttpMessageConverter formConverter = new FormHttpMessageConverter();
        formConverter.setCharset(Charset.forName("UTF8"));
        restTemplate.getMessageConverters().add(formConverter);
        restTemplate.getMessageConverters().add(new MappingJackson2HttpMessageConverter());

        restTemplate.setRequestFactory(new HttpComponentsClientHttpRequestFactory());

        HttpHeaders httpHeaders = new HttpHeaders();
        httpHeaders.setAccept(Collections.singletonList(MediaType.parseMediaType("application/json")));

        MultiValueMap<String, Object> parts = new LinkedMultiValueMap<String, Object>();

        parts.add(Constants.STATION_PROFILE_IMAGE_FILE, new FileSystemResource(stationImage.getImageFile()));
        parts.add(Constants.STATION_PROFILE_IMAGE_URI, stationImage.getImageUri());
        parts.add(Constants.STATION_PROFILE_IMAGE_TYPE, stationImage.getImageType());
        parts.add(Constants.FIELD_STATION_ID, stationImage.getStationId());

        return restTemplate.postForObject(Constants.REST_CLIENT_URL_ADD_IMAGE, parts, Boolean.class);
    } catch (Exception e) {
        StringWriter sw = new StringWriter();
        e.printStackTrace(new PrintWriter(sw));

        Log.e(TAG + ":addStationImage", sw.toString());
    }

    return false;
}

这应该可以解决问题。我添加了尽可能多的信息，因为我花了几天时间拼凑出完整问题的各个部分，我希望这会有所帮助。

Answer 5

我们其中一个人使用 filesystemresource 做了类似的事情。试试

mvm.add("file", new FileSystemResource(pUploadDTO.getFile()));

假设 .getFile 的输出是一个java File对象，它应该和我们的一样工作，只有一个File参数。

Answer 6

您只需使用MultipartHttpServletRequest

即可

示例：

 @RequestMapping(value={"/upload"}, method = RequestMethod.POST,produces = "text/html; charset=utf-8")
 @ResponseBody
 public String upload(MultipartHttpServletRequest request /*@RequestBody MultipartFile file*/){
    String responseMessage = "OK";
    MultipartFile file = request.getFile("file");
    String param = request.getParameter("param");
    try {
        System.out.println(file.getOriginalFilename());
        System.out.println("some param = "+param);
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(file.getInputStream(), StandardCharsets.UTF_8));
        // read file
    }
    catch(Exception ex){
        ex.printStackTrace();
        responseMessage = "fail";
    }
     return responseMessage;
}

request.getParameter()中的参数名称必须与对应的前端名称相同。

请注意，该文件是通过getFile()提取的，而其他参数是通过getParameter()

提取的

Answer 7

我必须做同样的事情@Luxspes上面做的......我使用的是Spring 4.2.6。花了很长时间才弄清楚为什么ByteArrayResource从客户端转移到服务器，但服务器没有识别它。

ByteArrayResource contentsAsResource = new ByteArrayResource(byteArr){
            @Override
            public String getFilename(){
                return filename;
            }
        };

Answer 8

如果你必须发送一个由一个需要用特定的HttpMessageConverter转换的对象组成的多部分文件，你就得到了没有合适的HttpMessageConverter＆＃34;错误无论您尝试什么，您可能想尝试这个：

RestTemplate restTemplate = new RestTemplate();
FormHttpMessageConverter converter = new FormHttpMessageConverter();

converter.addPartConverter(new TheRequiredHttpMessageConverter());
//for example, in my case it was "new MappingJackson2HttpMessageConverter()"

restTemplate.getMessageConverters().add(converter);

这解决了我使用自定义对象的问题，该文件与文件（在我的情况下为instanceof FileSystemResource）一起是我需要发送的多部分文件的一部分。我尝试使用TrueGuidance的解决方案（以及在网络上发现的许多其他解决方案）无济于事，然后我查看了FormHttpMessageConverter的源代码并试了一下。

Answer 9

您必须将FormHttpMessageConverter添加到applicationContext.xml才能发布多部分文件。

<bean id="restTemplate" class="org.springframework.web.client.RestTemplate">
    <property name="messageConverters">
        <list>
            <bean class="org.springframework.http.converter.StringHttpMessageConverter" />
            <bean class="org.springframework.http.converter.FormHttpMessageConverter" />
        </list>
    </property>
</bean>

有关示例，请参阅http://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/http/converter/FormHttpMessageConverter.html。

Answer 10

我遇到了这个问题，找到了比使用ByteArrayResource更简单的解决方案。

只需

public void loadInvoices(MultipartFile invoices, String channel) throws IOException {

    init();

    Resource invoicesResource = invoices.getResource();

    LinkedMultiValueMap<String, Object> parts = new LinkedMultiValueMap<>();
    parts.add("file", invoicesResource);

    HttpHeaders httpHeaders = new HttpHeaders();
    httpHeaders.setContentType(MediaType.MULTIPART_FORM_DATA);
    httpHeaders.set("channel", channel);

    HttpEntity<LinkedMultiValueMap<String, Object>> httpEntity = new HttpEntity<>(parts, httpHeaders);

    String url = String.format("%s/rest/inbound/invoices/upload", baseUrl);

    restTemplate.postForEntity(url, httpEntity, JobData.class);
}

它有效，并且不会弄乱文件系统或字节数组。

使用RestTemplate请求将Multipart File作为POST参数发送

10 个答案: