No response, if BSP page is called in loop

I have in my ABAP program an internal table with several rows of data. I loop over the table and call the same BSP page for each entry. The goal is to read the data of each line in HTML format and then download it as an HTML file.

Problem is: the first call (first run) works perfectly and returns HTML text, but on next calls (next data lines) the method http_client->response->get_cdata( ) does not return any data, even though everything ran without errors (response status = 200).

Two more points:

1. I edited the code so that the http_client instance is created outside the loop (call method cl_http_client=>create_internal()), but unfortunately it didn't work either.
2. I debugged it, the request went through to the BSP app (page) every time for every data entry, but I can't track where the data is lost afterwards!

Thanks in advance.

Here is the call logic:

loop at it_data .....
  ......
  ......

   CALL METHOD cl_http_ext_webapp=>create_url_for_bsp_application
      EXPORTING
        bsp_application      = iv_app
        bsp_start_page       = iv_page
        bsp_start_parameters = lt_params      
      IMPORTING
        abs_url              = lv_url.

*   Create internal http client
    CALL METHOD cl_http_client=>create_internal
      IMPORTING
        client            = lr_http_client
      EXCEPTIONS
        plugin_not_active = 1
        internal_error    = 2
        OTHERS            = 3.
    IF sy-subrc <> 0.
      ev_error = abap_true.
      RETURN.
    ENDIF.

    cl_http_utility=>set_request_uri( request  = lr_http_client->request
                                                 uri      = lv_url ).

    lr_http_client->request->set_header_field( name  = '~request_method'
                                                       value = 'GET' ).


*   Send and recieve
    lr_http_client->send(
      EXCEPTIONS
        http_communication_failure = 1
        http_invalid_state         = 2
        http_processing_failed     = 3
        http_invalid_timeout       = 4
        OTHERS                     = 5
    ).
    IF sy-subrc = 0.
      lr_http_client->receive(
        EXCEPTIONS
          http_communication_failure = 1
          http_invalid_state         = 2
          http_processing_failed     = 3
          OTHERS                     = 4
      ).
    ENDIF.

    IF sy-subrc <> 0.
      CALL METHOD lr_http_client->get_last_error
        IMPORTING
          code    = lv_rc
          message = lv_message.
      ev_error = abap_true.
      RETURN.
    ENDIF.

    lr_http_client->response->get_status( IMPORTING code   = lv_rc
                                                    reason = lv_reason ).
    IF lv_rc = 200.
      ev_html = lr_http_client->response->get_cdata( ).
    ELSE.
      ev_error = abap_true.
      RETURN.
    ENDIF.

    lr_http_client->close( ).

endloop.

Thanks for your help.

The error lies in the BSP app Settings. I solved it as follows: 1- BSP application properties -> set as stateful. 2- BSP page Properties->Lifetime changed to 'Request'. (this determines how long the instance of the page/controller will be retained.)

It worked properly now.