ABAP自定义类的构造方法

REPORT ytest_011. 

*----------------------------------------------------------------------* 
*       CLASS zcl_eventsreceive DEFINITION 
*----------------------------------------------------------------------* 
*
*----------------------------------------------------------------------* 
CLASS zcl_eventsreceive DEFINITION .
  PUBLIC SECTION.
    METHODS :
      say , 
      constructor
        IMPORTING 
          input TYPE char10.
    DATA data_type TYPE char10 .
ENDCLASS.                    "zcl_eventsreceive DEFINITION 
*&---------------------------------------------------------------------* 
*&       Class (Implementation)  zcl_eventsreceive 
*&---------------------------------------------------------------------* 
*        Text 
*----------------------------------------------------------------------* 
CLASS zcl_eventsreceive IMPLEMENTATION .
  METHOD constructor. 
    data_type = input.
  ENDMETHOD.                    "constructor

  METHOD say. 
    MESSAGE s000(oo) WITH data_type .
  ENDMETHOD.                    "SAY
ENDCLASS.               "zcl_eventsreceive

START-OF-SELECTION.
  DATA lcl_cls_1 TYPE REF TO zcl_eventsreceive.
  DATA lcl_cls_2 TYPE REF TO zcl_eventsreceive.

  CREATE OBJECT lcl_cls_1
    EXPORTING 
      input = 'SVICE1'. 
  CREATE OBJECT lcl_cls_2
    EXPORTING 
      input = 'SVICE2'. 

  WRITE:/ '== GO =='.
  CALL METHOD lcl_cls_1->say.
  CALL METHOD lcl_cls_2->say.
  WRITE:/ '== END =='.

以后写一个用同一个类响应多个ALV的事件的用法会用到自定义构造方法