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使用ajax和Servlet版本3:request上载文件。getPart()为空

primefaces servlets ajax

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Alex Mi · 技术社区 · 8 年前

我的应用程序曾经正常工作:我使用的是PrimeFaces 6,但我想使用Servlet版本3和ajax上传一个文件。

我使用这些源代码开发代码:

using two forms in a JSF template

Upload a file using Servlet 3.0

Mozilla Guide for using ajax to upload an image - part I

Mozilla Guide for using ajax to upload an image - part II

在我的模板(视图)中,我有两个表单。第一个用于收集客户数据,第二个是我使用ajax(Java脚本)和servlet版本3为该客户上传图片的表单。一切正常,但在负责处理我上传的图像的servlet中,我得到了对部件的空引用。这里是我的代码:

1)视图摘录(PrimeFaces facelet):

 <h:form id="newCustomerformId">
  <!-- rest of code not shown here -->
   <p:commandButton type="submit" value="Create Customer"
                                    icon="ui-icon-check"
                                    actionListener="#   {newCustomerBean.saveNewCustomer}"
                                    update = "@form"
                                    oncomplete="ajaxUploadFile();"/>            

    </h:form>

    <h:form id="uploadImageForNewCustomerformId"
        enctype="multipart/form-data">
        <div id="dropzone">
            <img id="librarypreview" src='' alt='library'
                    style="width: 280px; height: 160 px;" />
             <select name="top5" id="flist" size="5" onchange="previewFile()">
             </select>
            <output id="list"> </output>
        </div>
            <input id="fileInput" type="file" multiple="multiple"></input>
            <span id="uploadStatusId"></span>
   </h:form>

2.)My ajaxUploadFile()JavaScript函数:

function ajaxUploadFile() {
    var form = document.getElementById('uploadImageForNewCustomerformId');

    if (form == null)
        return;

     var formData = new FormData(form);

     for (var i = 0; i < fileList.length; i ++){
       //append a File to the FormData object
       formData.append("file", fileList[i], fileList[i].name);
     }

    var uploadStatusOutput = document.getElementById("uploadStatusId");
    var request = new XMLHttpRequest();
    request.open("POST", "/javakurs3-biliothek-jsf-mobile/fileUpload");
    request.responseType = 'text';
    request.onload = function(oEvent) {

        if (request.readyState === request.DONE) {
            if (request.status === 200) {
                if (request.responseText == "OK") {
                    form.action = "/javakurs3-biliothek-jsf-mobile/pages/customers.jsf";
                    form.submit();
                    return;
                }
            } 
            uploadStatusOutput.innerHTML = "Error uploading image";

        } // request.readyState === request.DONE

    };  // function (oEvent)

    request.send(formData);
};

3.)My servlet版本3处理上载的图像:

@WebServlet("/fileUpload")
@MultipartConfig
public class ImageUploadServlet extends HttpServlet {



    @Override
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException {

        HttpSession session = request.getSession(false);

        System.out.println(session);

        Long savedKundeId = (Long) session.getAttribute(NewCustomerBean.SESSION_ATTRIBUTE_CUST_ID);     

        Part filePart = null;
        PrintWriter pw = null;
        try {
            filePart = request.getPart("file");

我的问题是filePart=请求。getPart(“文件”);返回null。

我如何解决这个问题?

谢谢你并致以诚挚的问候:亚历克斯

2 回复 | 直到 8 年前

1

Alex Mi 8 年前

@Java武士:谢谢你的建议:我把它应用到我的代码中,现在它按预期工作。以下是“解决方案”:

    Part filePart = null;
    String fileNamer = null;


    try {
        for (Part fPart : request.getParts()){
            if (fPart.getName()!=null && fPart.getName().equals("file") && StringUtils.isNotEmpty(fPart.getSubmittedFileName())){
                fileNamer =  fPart.getSubmittedFileName();
                filePart = fPart;
                break;
            }
        }

2

0

Java Samurai 8 年前

您应该使用getParts获取所有部件并检查名称。我认为“