如何为持久性 class 创建非持久性抽象 superclass

Question

我想为我的持久性 classes 创建一个抽象超级 class，它提供了一些函数来查询任何其他持久性 class 的成员 class =].

所以我尝试将这个摘要 class 添加为 superclass，但出现以下错误：

The superclass of a persistent class must be persistent

Message no. OO629

有什么好的解决方法吗？（我的意思是不同于制作接口并将函数复制粘贴到每个子class）

这里有一些额外的信息：

Here is what I want to do (Try IE if it does not work with chrome or friefox

简短摘要：

（我在user工作）
创建一个通用函数来查询每个键。
使用通用函数创建更具体的函数以查询来自联接 table(user_has_tag) 的所有“链接”，将它们填充到属性中
再次使用通用函数查询另一个外键（tag）。

这里是我的抽象superclass（具有通用函数QUERY_BY_UUID:

CLASS zcl_ps_hrmobject DEFINITION
  PUBLIC
  ABSTRACT
  CREATE PUBLIC .

  PUBLIC SECTION.

    METHODS get_uuid
      RETURNING
        VALUE(ro_uuid) TYPE uuid .
  PROTECTED SECTION.

    METHODS query_by_uuid
      IMPORTING
        !ir_agent         TYPE REF TO object
      RETURNING
        VALUE(rt_entries) TYPE osreftab
      RAISING
        cx_os_object_not_found
        cx_os_query_error .
    METHODS get_query
      RETURNING
        VALUE(rr_query) TYPE REF TO if_os_query .
  PRIVATE SECTION.

    CONSTANTS lc_query_method_name TYPE string VALUE 'IF_OS_CA_PERSISTENCY~GET_PERSISTENT_BY_QUERY'. "#EC NOTEXT
    DATA mlr_query TYPE REF TO if_os_query .
ENDCLASS.



CLASS zcl_ps_hrmobject IMPLEMENTATION.


* <SIGNATURE>---------------------------------------------------------------------------------------+
* | Instance Protected Method ZCL_PS_HRMOBJECT->GET_QUERY
* +-------------------------------------------------------------------------------------------------+
* | [<-()] RR_QUERY                       TYPE REF TO IF_OS_QUERY
* +--------------------------------------------------------------------------------------</SIGNATURE>
  METHOD get_query.
    rr_query = me->mlr_query.
  ENDMETHOD.


* <SIGNATURE>---------------------------------------------------------------------------------------+
* | Instance Public Method ZCL_PS_HRMOBJECT->GET_UUID
* +-------------------------------------------------------------------------------------------------+
* | [<-()] RO_UUID                        TYPE        UUID
* +--------------------------------------------------------------------------------------</SIGNATURE>
  METHOD get_uuid.
* must be implemented in subclass

    RAISE EXCEPTION TYPE cx_os_no_implementation
*      EXPORTING
*        textid =
*        previous =
      .
  ENDMETHOD.


* <SIGNATURE>---------------------------------------------------------------------------------------+
* | Instance Protected Method ZCL_PS_HRMOBJECT->QUERY_BY_UUID
* +-------------------------------------------------------------------------------------------------+
* | [--->] IR_AGENT                       TYPE REF TO OBJECT
* | [<-()] RT_ENTRIES                     TYPE        OSREFTAB
* | [!CX!] CX_OS_OBJECT_NOT_FOUND
* | [!CX!] CX_OS_QUERY_ERROR
* +--------------------------------------------------------------------------------------</SIGNATURE>
  METHOD query_by_uuid.
    DATA: lr_query TYPE REF TO if_os_query,
          lr_uuid  TYPE uuid.

    lr_query = me->get_query( ).
    lr_uuid  = me->get_uuid( ).

*TRY.
    CALL METHOD ir_agent->(lc_query_method_name)
      EXPORTING
        i_query = lr_query
*       i_parameter_tab =
        i_par1  = lr_uuid
*       i_par2  =
*       i_par3  =
*       i_subclasses    = OSCON_FALSE
*       i_upto  = 0
*       i_options       = IF_OS_QUERY_OPTIONS=>DEFAULT_OPTIONS
      RECEIVING
        result  = rt_entries.
* CATCH cx_os_object_not_found .
* CATCH cx_os_query_error .
*ENDTRY.


  ENDMETHOD.
ENDCLASS.

Answer 1

没有。不过，您的描述听起来您可能想仔细查看生成的代理类和查询服务提供的方法。

Answer 2

我用一个接口和一个静态辅助类解决了这个问题。

接口强制执行三个 getter:

get_uuid ( )
get_query ( )
get_query_method_name ( )

现在每个元素都实现了这个接口。

在 helperclass 中，我现在有我想要继承的 Query_by_uuid 函数，它获取该接口的实例类型 (ir_root_instance)。

这里是函数

  METHOD QUERY_BY_UUID.
    DATA: lr_query             TYPE REF TO if_os_query,
          lr_uuid              TYPE uuid,
          lv_query_method_name TYPE string.

    lr_query             = ir_root_instance->get_query( ).
    lr_uuid              = ir_root_instance->get_uuid( ).
    lv_query_method_name = ir_root_instance->get_query_method_name( ).

*TRY.
    CALL METHOD ir_agent->(lv_query_method_name)
      EXPORTING
        i_query = lr_query
*       i_parameter_tab =
        i_par1  = lr_uuid
*       i_par2  =
*       i_par3  =
*       i_subclasses    = OSCON_FALSE
*       i_upto  = 0
*       i_options       = IF_OS_QUERY_OPTIONS=>DEFAULT_OPTIONS
      RECEIVING
        result  = rt_entry.
* CATCH cx_os_object_not_found .
* CATCH cx_os_query_error .
*ENDTRY.


  ENDMETHOD.

如何为持久性 class 创建非持久性抽象 superclass

How to create a not persistent abstract superclass for a persistent class

inheritance

abap

persistence

这里有一些额外的信息：