Java 400（错误请求）错误-使用JQuery AJAX上载Spring启动文件

我正在尝试使用thymeleaf ajax和spring boot上传图片。我已经使用了在stackoverflow和其他论坛上找到的大部分帖子，但我似乎确实在工作。我已经在我的安全配置中添加了CSRF，并将其包含在ajax上传脚本中，但仍然面临“400（错误请求）”错误

异常错误

017-03-01 23:50:06.893 ERROR 58753 --- [nio-8080-exec-3] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.web.multipart.MultipartException: Could not parse multipart servlet request; nested exception is org.apache.commons.fileupload.FileUploadException: Stream closed] with root cause

java.io.IOException: Stream closed
    at org.apache.catalina.connector.InputBuffer.read(InputBuffer.java:372) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
    at org.apache.catalina.connector.CoyoteInputStream.read(CoyoteInputStream.java:190) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
    at java.io.FilterInputStream.read(FilterInputStream.java:133) ~[na:1.8.0_65]
    at org.apache.commons.fileupload.util.LimitedInputStream.read(LimitedInputStream.java:134) ~[commons-fileupload-1.3.2.jar:1.3.2]
    at org.apache.commons.fileupload.MultipartStream$ItemInputStream.makeAvailable(MultipartStream.java:999) ~[commons-fileupload-1.3.2.jar:1.3.2]
    at org.apache.commons.fileupload.MultipartStream$ItemInputStream.read(MultipartStream.java:903) ~[commons-fileupload-1.3.2.jar:1.3.2]
    at java.io.InputStream.read(InputStream.java:101) ~[na:1.8.0_65]
    at org.apache.commons.fileupload.util.Streams.copy(Streams.java:100) ~[commons-fileupload-1.3.2.jar:1.3.2]
    at org.apache.commons.fileupload.util.Streams.copy(Streams.java:70) ~[commons-fileupload-1.3.2.jar:1.3.2]
    at org.apache.commons.fileupload.MultipartStream.readBodyData(MultipartStream.java:593) ~[commons-fileupload-1.3.2.jar:1.3.2]

上传

<form id="upload-file-input" th:action="@{/uploadFile}" method="post" th:object="${picture}" enctype="multipart/form-data" class="form-inline inline new-item">
        <div th:replace="common/layout :: flash"></div>
        <fieldset>
            <legend> Upload Picture</legend>
        <div class="row">
            <div class="col s12 l8">
                <div class="file-wrapper">
                    <input type="file" id="file" name="uploadfile"/>
                    <span class="placeholder" data-placeholder="Choose an image...">Choose an image...</span>
                    <label for="file" class="button">Browse</label>
                    <span id="upload-file-message"></span>
                </div>
            </div>
            <button type="submit" class="btn btn-primary">Upload</button>
        </div>
        </fieldset>
        <div class="style16"></div>
    </form>

Upload.js

var token = $("meta[name='_csrf']").attr("content");
$.ajaxSetup({
    beforeSend: function(xhr) {
        xhr.setRequestHeader('X-CSRF-TOKEN', token);
    }
});

var $form = $("#upload-file-input");
  $form.on("submit", function(e){
   e.preventDefault();
   $.ajax({
           url: $form.prop('action'),
           type: "POST",
           data: new FormData($("#upload-file-input")[0]),
           enctype: 'multipart/form-data',
           processData: false,
           contentType: false,
           cache: false,
           success: function () {
             // Handle upload success
             $("#upload-file-message").text("File succesfully uploaded");
           },
           error: function () {
             // Handle upload error
             $("#upload-file-message").text("File not uploaded (perhaps it's too much big)");
           }
         });
     });

---

您的错误的根本原因似乎是

嵌套异常为org.springframework.web.multipart.MultipartException:无法分析多部分servlet请求

这让我相信您的服务器端工作正常，但客户端没有以预期的格式发送数据

您可以尝试将ajax调用改为以下内容吗

// create a new form
var formData = new FormData();

// add your binary value to the file key
formData.append("file", fileBinary);


$.ajax({dataType : 'json',
    ...
    data : formData,                // add the form
    ...

然后在服务器端，上传的文件对象将出现在

文件

参数中

public String uploadFile(@RequestParam("file") MultipartFile uploadfile) {

---

试着像这样获取表单数据

let uploadFile = $('#upload-file-input')[0];
let formData = new FormData(uploadFile);

---

在

ajax

data

属性中发送此表单数据。

问题的原因是

java.io.IOException:Stream closed

。这很可能意味着在多部分请求解析开始之前，某些代码已经在

HttpServletRequest

的

InputStream

上调用了

close（）

一个可能的罪魁祸首可能是servlet

Filter

的一个有缺陷的实现，该实现使用缓存装饰器（除了多部分处理之外，它在大多数操作中使用缓存的请求内容）包装请求，并在将修饰的请求传递给进一步处理之前关闭输入流

通过调试查看

HttpServletRequest

的

InputStream

上的

close

调用，应该可以发现罪魁祸首

---

如果由于某种原因，这很困难，您也可以尝试禁用任何第三方筛选器（各种验证、日志记录、监视筛选器等），看看问题是否仍然存在。

您是否遇到过异常？@MattClark Yes ido@MattClark抛出IOExceptionI将值添加到formData.append（“file”，$（'input[type=“file”]”）中[0]）.val（）；但是得到一个错误rg.springframework.web.multipart.MultipartException：当前请求不是一个多部分请求-

let uploadFile = $('#upload-file-input')[0];
let formData = new FormData(uploadFile);