Ajax上传文件&FromData与服务器使用DiskFileItemFactory&ServletFileUpload&FileItem接收文件

html代码

<form id="form" method="post" >
    图片名称：<input id="id" name="id">
    <input type="file" name="img" accept="image/gif/png/jpg/" >
</form>
<button id="bt">提交</button>

jquery代码

<script src="https://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
<script>
    $(function () {
        $('#bt').on('click',function () {
            var formData = new FormData($('#form')[0]);
            $.ajax({
                url:"http://localhost:8080/webMessage_war_exploded/HeadImgServlet",
                data:formData,
                type:'post',
                dataType:'text',
                processData:false,
                contentType:false,
                success:function () {
                    alert("ok");
                }
            });
        })
    })
</script>

需要导包jar包

servlet 代码

@WebServlet(name = "HeadImgServlet",urlPatterns = "/HeadImgServlet")
public class HeadImgServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setHeader("Access-Control-Allow-Origin","*");
        DiskFileItemFactory factory = new DiskFileItemFactory();
        ServletFileUpload upload = new ServletFileUpload(factory);
        String id = null;
        FileItem file = null;
        String fileType = null;
        try {
            List<FileItem> list = upload.parseRequest(request);
            for (FileItem fileItem : list){
                if (fileItem.isFormField()){
                    String name = fileItem.getFieldName();
                        id = fileItem.getString("utf-8");
                        System.out.println(name);
                        System.out.println(id);
                }else{
                    file = fileItem;
                    String name = fileItem.getName();
                    fileType = name.substring(name.lastIndexOf("."));
                }
            }
        } catch (FileUploadException e) {
            e.printStackTrace();
        }

        File f = new File("E:\\上传的文件\\"+id+fileType);
        try {
            file.write(f);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    doPost(request,response);
    }

效果展示