Implementing a WebSocket Client using Push Channel Protocol (PCP)

プッシュチャネルプロトコルのサブプロトコル<v10.pcp.sap.com>を使用するWebSocketクライアントの簡単な例として、WebSocketサーバーアプリケーションを使用できますPING_PCP。このテストでは、トランザクションSMICMのHTTPポートと、トランザクションSICFのアプリケーションパス/ sap / bc / apc / sap/ping_pcpがアクティブである必要があります。宛先として、内部宛先NONE（宛先タイプを参照）を選択します。これは、クライアントも実行される同じサーバーへの接続（この場合はHTTP / WebSocket接続）を作成するために使用されます。

次のレポートYRS_APC_WSP_CLIENT_PCPは、プッシュチャネルプロトコル（PCP）を使用したWebSocketクライアントの簡単な実装を提供します。

サンプルコード

REPORT YRS_APC_WSP_CLIENT_PCP.PARAMETERS: rel_url TYPE string LOWER CASE DEFAULT '/sap/bc/apc/sap/ping_pcp?send_by=apc',            "path & query for APC WebSocket server application PING_STATELESS            fname   TYPE string LOWER CASE DEFAULT 'action', " PCP field name            fvalue  TYPE string LOWER CASE DEFAULT 'testing',            message TYPE string LOWER CASE DEFAULT 'Say hello !'," PCP field value            send_no TYPE i DEFAULT 2." number of messages being sent" implementing class for the event handler interface IF_APC_WSP_EVENT_HANDLER_PCPclass lcl_apc_handler definitionfinalcreate public .PUBLIC SECTION.  INTERFACES: if_apc_wsp_event_handler_pcp.  DATA      : mo_message_pcp TYPE REF TO if_ac_message_type_pcp,              m_message      TYPE string.ENDCLASS.CLASS lcl_apc_handler IMPLEMENTATION.  METHOD if_apc_wsp_event_handler_pcp~on_open.  ENDMETHOD.  METHOD if_apc_wsp_event_handler_pcp~on_message.    " message handling section    TRY.        " save the message body        m_message = i_message->get_text( ).        " save pcp message        mo_message_pcp = i_message.      CATCH cx_apc_error INTO DATA(lx_apc_error).        m_message = lx_apc_error->get_text( ).      CATCH cx_ac_message_type_pcp_error INTO DATA(lx_pcp_error).        m_message = lx_pcp_error->get_text( ).    ENDTRY.  ENDMETHOD.  METHOD if_apc_wsp_event_handler_pcp~on_close.    "close handling    m_message = 'Connection closed !'.  ENDMETHOD.  METHOD if_apc_wsp_event_handler_pcp~on_error.    "error/close handling  ENDMETHOD.ENDCLASS.START-OF-SELECTION.  DATA: lo_client          TYPE REF TO if_apc_wsp_client.  DATA: lo_event_handler   TYPE REF TO lcl_apc_handler.  DATA: lo_message_manager TYPE REF TO if_apc_wsp_message_manager_pcp.  DATA: lo_message         TYPE REF TO if_ac_message_type_pcp. "PCP message type  DATA: lt_fields          TYPE pcp_fields.  TRY.      " create the event handler object,  the interface IF_APC_WSP_EVENT_HANDLER is implemented in local class lcl_apc_handler      CREATE OBJECT lo_event_handler.      " create the WebSocket client object      lo_client = cl_apc_wsp_client_manager=>create_by_destination(                        i_destination      = 'NONE'  "NONE refers to the HTTP host & port of present server                        i_event_handler = lo_event_handler                        i_protocol      = if_apc_wsp_event_handler_pcp=>co_event_handler_type ).      " set the application path and query      DATA(lo_request) = lo_client->get_context( )->get_initial_request( ).      lo_request->set_path_and_query( i_relative_uri = rel_url ).         " initiate the connection setup, successful connect leads to execution of ON_OPEN      lo_client->connect( ).        " create message manager and message object of type PCP for sending of PCP messages        lo_message_manager ?= lo_client->get_message_manager( ).        lo_message         ?= lo_message_manager->create_message( ).        lo_message->set_field( i_name = fname i_value = fvalue ).        lo_message->set_text( message ).      " number of messages being sent      DO send_no TIMES.        lo_message_manager->send( lo_message ).        " wait for incoming message sent by peer        CLEAR: lo_event_handler->m_message, lo_event_handler->mo_message_pcp.        WAIT FOR PUSH CHANNELS UNTIL lo_event_handler->m_message IS NOT INITIAL UP TO 10 SECONDS.        IF sy-subrc = 8.          WRITE: / 'Timeout occured !'.        ELSE.          lo_event_handler->mo_message_pcp->get_fields( CHANGING c_fields = lt_fields ).          WRITE: / 'Received PCP message body: ', lo_event_handler->m_message.          LOOP AT lt_fields ASSIGNING FIELD-SYMBOL(<lv_field>).            WRITE: / sy-tabix, 'field name : ', <lv_field>-name,                   / sy-tabix, 'field value: ', <lv_field>-value.          ENDLOOP.        ENDIF.      ENDDO.      " close WebSocket connection      lo_client->close( i_reason = 'application closed connection !' ).    CATCH cx_apc_error INTO DATA(lx_apc_error).      MESSAGE lx_apc_error->get_text( ) TYPE 'E'.  ENDTRY.