FileUploadException：请求被拒绝，因为没有找到多部分边界

Question

我需要使用 http 处理来自客户端的文件。服务器端是在 Spring Boot 上编写的。这个请求控制器端

 @RequestMapping(value = "/upload", method = RequestMethod.POST)
    @ResponseBody
    public void uploadFile(@RequestParam("file") MultipartFile uploadfile) {
        System.out.println("filename: " + uploadfile.getName());
    }

路径文件的客户端是；

public static void main(String[] args) throws IOException {

        URL url = new URL(UPLOAD_URL);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setDoOutput(true);
        conn.setRequestMethod("POST");
        conn.setRequestProperty("Content-Type", "multipart/form-data");
        File file = new File("test.txt");
//init array with file length
        byte[] bytesArray = new byte[(int) file.length()];

        FileInputStream fis = new FileInputStream(file);
        fis.read(bytesArray); //read file into bytes[]
        fis.close();
        OutputStream os = conn.getOutputStream();
        os.write(bytesArray);
        os.flush();



        conn.disconnect();
    }

但是我有以下错误

org.apache.tomcat.util.http.fileupload.FileUploadException: the request was rejected because no multipart boundary was found
    at org.apache.tomcat.util.http.fileupload.FileUploadBase$FileItemIteratorImpl.<init>(FileUploadBase.java:840) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.tomcat.util.http.fileupload.FileUploadBase.getItemIterator(FileUploadBase.java:256) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.tomcat.util.http.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:280) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.connector.Request.parseParts(Request.java:2843) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.connector.Request.parseParameters(Request.java:3219) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.connector.Request.getParameter(Request.java:1119) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.connector.RequestFacade.getParameter(RequestFacade.java:381) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:75) ~[spring-web-4.3.8.RELEASE.jar:4.3.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.8.RELEASE.jar:4.3.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) ~[spring-web-4.3.8.RELEASE.jar:4.3.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.8.RELEASE.jar:4.3.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478) [tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80) [tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799) [tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861) [tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455) [tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.14.jar:8.5.14]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_71]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_71]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.14.jar:8.5.14]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_71]

请帮帮我，我找不到原因

Answer 1

我也面临同样的问题。 不要在 Postman 的“Header”选项卡中输入任何值。 （注：它在正文选项卡旁边） 这解决了我的问题

Answer 2

您没有将数据写入多部分结构中的连接。

您可以使用question 的答案作为指导：

Answer 3

正如异常所说，您的请求缺少一些信息：边界。 multipart/form-data 应该是这样的：

POST /upload HTTP/1.1
Host: myhost
User-Agent: uploader/1.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Content-Type: multipart/form-data; boundary=----------287032381131322
Content-Length: {sizeofcontent}

------------287032381131322
Content-Disposition: form-data; name="file"; filename="myfile.txt"
Content-Type: text/plain

My file content;
------------287032381131322--

看到内容类型中的边界参数被用作每个数据的分隔符（它可以是任何字符串）。 注意末尾额外的“--”以通知数据结束。您需要编写这些才能成功上传文件。