Multipart Request在android中不起作用？

Question

我尝试使用带有参数的multipart上传图像，但它给了我500

发送值：

UserId - 97
Username - TEST
listpref :[Test 1,Test 2,Test 3]
filepath: file:///storage/emulated/0/Pictures/Clee_Photos/IMG_20160518_102926.jpg

MultiPartRequest multiPartRequest=new MultiPartRequest(Request.Method.POST, CleeApp.ADD_UPDATE_PREF, new Response.Listener() {
           @Override
           public void onResponse(Object response) {
               CustomDialog.dismissProgressDialog();
               Log.i(LOGTAG, "Multipart Response " + response.toString());

           }
       }, new Response.ErrorListener() {
           @Override
           public void onErrorResponse(VolleyError error) {
               CustomDialog.dismissProgressDialog();
           }
       }){
           @Override
           protected Response parseNetworkResponse(NetworkResponse response) {

               CustomDialog.dismissProgressDialog();
               Log.i(LOGTAG, "Multipart Network Response " + response.toString());
               return null;
           }

           @Override
           public int compareTo(Object another) {
               return 0;
           }
       };
        multiPartRequest.addMultipartParam("userId","text",userId);
        multiPartRequest.addMultipartParam("displayName","text",displayName);
        multiPartRequest.addMultipartParam("listPref","text",listPref);
        multiPartRequest.addFile("file", filepath);