jQuery的FormData不与Servlet一起工作[复制](jquery FormData not working with Servlet [duplicate])

 
 
 这个问题在这里已经有了答案： 
 
 
 
  
 如何使用JSP / Servlet和Ajax将文件上传到服务器？ 4个答案 
 
 
 
 
 我使用jQuery FormData将一个文件发送到tomcat服务器。 该文件正在服务器上成功接收，但没有收到我用该文件发送的任何其他值。 为了处理文件上传，我使用了http://commons.apache.org/proper/commons-fileupload/和http://commons.apache.org/io/ 。 它以某种方式获取我的文件。 但是，当我写 
 
request.getParameter("file")
 
 在下面的代码的servlet中，它返回null。 即使它不显示请求对象中的任何参数。 我不明白它是如何获得文件。 任何人都可以帮我解决这个问题吗？ 
 
$('#uploadCourseDetail').click(function() {
    var form_data = new FormData();
    if (!($('#courseDetails').prop('files')[0] == undefined)) {
        var file_data = $('#courseDetails').prop('files')[0];
        form_data.append('file', 'examdetail');
        form_data.append('courseDetails', file_data);
    }
    $.ajax({
        url: 'Exam_TimeTable_Scheduler_bySlots_Web_Project/FileUploadServlet',
        type: 'POST',
        contentType: false,
        processData: false,
        cache: false,
        data: form_data,
        success: function(data) {
            alert("File Uploaded Successfully !");
        }
    });
});
 
 我使用萤火虫追踪请求。 它显示这两个字段正在发送到服务器。 以下是相同的快照：  

 
 
This question already has an answer here:
 
 
 
  
 How to upload files to server using JSP/Servlet and Ajax?  4 answers  
 
 
 
 
I am sending one file to the tomcat server using jQuery FormData. The file is being received successfully on the server but any other value which I send with the file is not being received. For processing the file upload, I am using http://commons.apache.org/proper/commons-fileupload/ and http://commons.apache.org/io/. It is getting my file somehow. But when I write 
 
request.getParameter("file")
 
in the servlet for the below code, it returns null. Even it doesn't show any parameter in the request object. I don't understand how it gets the file then. Can anyone help me to solve this?
 
$('#uploadCourseDetail').click(function() {
    var form_data = new FormData();
    if (!($('#courseDetails').prop('files')[0] == undefined)) {
        var file_data = $('#courseDetails').prop('files')[0];
        form_data.append('file', 'examdetail');
        form_data.append('courseDetails', file_data);
    }
    $.ajax({
        url: 'Exam_TimeTable_Scheduler_bySlots_Web_Project/FileUploadServlet',
        type: 'POST',
        contentType: false,
        processData: false,
        cache: false,
        data: form_data,
        success: function(data) {
            alert("File Uploaded Successfully !");
        }
    });
});
 
I use firebug to track the requests. It shows that both the fields are being sent to the server. Below is the snapshot for the same:

原文：https://stackoverflow.com/questions/43258751