My JSP page like this:
$(function() {  
    $("#file_upload").uploadify({  
        'height': 27,
        'width': 80,
        'buttonText':'浏览',
        'swf':'<%=basePath%>admin/tupian/js/uploadify.swf',
        'uploader': '<%=basePath%>Imguploadoper.img',
        'auto' : false,
        'fileTypeExts' : '*.jpg'
        });
});
Here is my java code:
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setHeaderEncoding("UTF-8");
try {
    //this line returns null
    List items = upload.parseRequest(request);
    Iterator itr = items.iterator();
    while (itr.hasNext()) {
        ......
    }
} catch (FileUploadException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
out.flush();
out.close();
upload.parseRequest(request) returns null. I really don't know the reason.
 
    