ABAP Help Document(29):14 Data Interface and Comunication Interfaces

14.Data Interfaces and Conmunication Interfaces

          ABAP提供与其他系统交互的数据接口。

14.1Remote Function Call(RFC)

          ABAP提供的调用远程系统功能的接口。

语法：

1. CALL FUNCTION func DESTINATION dest parameter_list.

parameter_list:

[EXPORTING  p1 = a1 p2 = a2 ...]
[IMPORTING  p1 = a1 p2 = a2 ...]
[TABLES     t1 = itab1 t2 = itab2 ...]
[CHANGING   p1 = a1 p2 = a2 ...]
[EXCEPTIONS [exc1 = n1 exc2 = n2 ...]
 [system_failure = ns [MESSAGE smess]]
[communication_failure = nc [MESSAGE cmess]]
[OTHERS = n_others]].

Synchronous RFC，同步RFC。

 

2. CALL FUNCTION func STARTING NEW TASK task

                [DESTINATION {dest|{IN GROUP {group|DEFAULT}}}]

                [{PERFORMING subr}|{CALLING meth} ON END OF TASK]

                parameter_list.

parameter_list:

[EXPORTING  p1 = a1 p2 = a2 ...]
[TABLES     t1 = itab1 t2 = itab2 ...]
[CHANGING   p1 = a1 p2 = a2 ...]
[EXCEPTIONS [exc1 = n1 exc2 = n2 ...]
[system_failure = ns [MESSAGE smess]]
[communication_failure = nc [MESSAGE cmess]]
[resource_failure      = nr [MESSAGE rmess]]
[OTHERS = n_others]].

Asynchronous RFC，异步RFC。

异步调用的一下显示配置参数：

profile parameter：

rdisp/rfc_min_wait_dia_wp：Number of available dialog work processes: 1;

rdisp/rfc_max_own_used_wp：Percentage of user-specific dialog work processes: 75% ;

rdisp/rfc_max_queue: Percentage of waiting requests in dialog queue: 5%;

rdisp/rfc_max_login: Percentage of logons to the system: 90%;

rdisp/rfc_max_own_login: Percentage of own logons to system: 25%;

rdisp/rfc_max_comm_entries: Percentage of used communication entries: 90%;

 

语法：

RECEIVE RESULTS FROM FUNCTION func

                [KEEPING TASK]

                parameter_list.

parameter_list:

[IMPORTING  p1 = a1 p2 = a2 ...]
[TABLES     t1 = itab1 t2 = itab2 ...]
 [CHANGING   p1 = a1 p2 = a2 ...]
[EXCEPTIONS [exc1 = n1 exc2 = n2 ...]
[system_failure = ns [MESSAGE smess]]
[communication_failure = nc [MESSAGE cmess]]
[OTHERS = n_others]].

通过RECEIVE获取异步function返回的结果。

语法：

WAIT UNTIL log_exp [UP TO sec SECONDS].

等待一段时间，执行之后语句。

 

3. CALL FUNCTION func IN BACKGROUND UNIT parameter_list.

Background RFC，后台RFC。

语法：CALL FUNCTION func IN BACKGROUND UNIT oref  parameter_list.

parameter_list:

EXPORTING  p1 = a1 p2 = a2 ... ]
[TABLES     t1 = itab1 t2 = itab2 ...]

oref为实现了接口IF_BGRFC_UNIT的类实例；

 

4. CALL FUNCTION func IN BACKGROUND TASK

                     [AS SEPARATE UNIT]

                     [DESTINATION dest]

                     parameter_list.

Transactional RFC ,推荐使用Background RFC。

          ABAP使用Tcode:SM59管理RFC Destination；

       RFC Function Exception: SYSTEM_FAILURE、COMMUNICATION_FAILURE、RESOURCE_FAILURE；

          RFC权限检查：profile parameter：auth/rfc_authority_check，配置为1，自动检查RFC权限；

       RFC Trust Relationships，使用Tcode：SMT1，配置受信任系统；

示例：DEMO_PARALLEL_RFC。

 

14.2 ABAP and XML

          Transformation Editor:使用Tcode:STRANS，编辑transformation程序。

1.ST

Simple Transformations(ST)：描述ABAP数据到XML格式转换；

ST Command命令：

ST Command	Meaning
<tt:apply ...>	Callss a subtemplate
<tt:assign ...>	Assigns a value to data
<tt:attribute ...>	Non-literal attribute
<tt:call ...>	Call an ST program
<tt:call-method ...>	Calls a static method or an instance method in ABAP Objects
<tt:cast ...>	Down casts reference variables
<tt:clear ...>	Initializes data
<tt:cond ...>	Conditional transformation
<tt:cond-var ...>	Condition for variables
<tt:context ...>	Context for local data roots in subtemplates
<tt:copy ...>	Transformation to and from asXML
<tt:create-object ...>	Creates objects in ABAP Objects
<tt:d-cond ...>	Conditional transformation for deserializations
<tt:deserialize ...>	Defines the transformation direction
<tt:empty ...>	Empty pattern
<... tt:extensible="..."...>	Extensibility of literal XML elements
<tt:front ...>	Initial part of a structured type
<tt:group ...>	Groups conditional transformations
<tt:include ...>	Includes an ST program
<... tt:lax="..." ...>	Compares names of literal XML elements
<tt:loop ...>	Loops across internal tables
<tt:namespace ...>	Defines a namespace
<tt:node ...>	Component of a type
<tt:parameter ...>	Declares parameters
<tt:read ...>	Reads a variable from XML
<tt:ref ...>	Sets the current node
<... tt:ref="..."...>	Sets the current node for a literal XML element
<tt:root ...>	Declares a data root
<tt:serialize ...>	Defines the transformation direction
<tt:s-cond ...>	Conditional transformation for serializations
<tt:skip ...>	SkipsXML elements in deserializations
<tt:switch ...>	Defines a case distinction between conditional transformations.
<tt:switch-var ...>	Case distinctions for variables
<tt:template ...>	Main template or subtemplates
<tt:text ...>	Literal Text
<tt:transform ...>	Root element of an ST program
<tt:type ...>	Type definition
<tt:value ...>	Transforms elementary data objects and structures
<... tt:value-ref ="..." ...>	Short form of the transformation of elementary data objects
<tt:variable ...>	Declares a variable
<tt:with-parameter ...>	Passes a value to ST programs, subtemplates, and ABAP methods
<tt:with-root ...>	Passes data to ST programs and subtemplates
<tt:write ...>	Writes a variable to XML

 

Namespaces:

1.http://www.sap.com/abapxml/types/dictionary describes the ABAP Dictionary.

2.http://www.sap.com/abapxml/types/type-pool/name describes the type group name.

3.http://www.sap.com/abapxml/types/class-pool/class describes the global class class.

4.http://www.sap.com/abapxml/types/defined/name describes the type that is defined in the current ST program using tt:type.

 

定义Root节点

<tt:transform [template="tmpl"]>
</tt:transform>

 

定义Type节点

<tt:type name="..." [[line-]type="..." [length="..."] [decimals="..."]]
  [extensible=extensible_flag]>

</tt:type>

ABAP数据类型：C, D, F, I, N, P, STRING, T, X or XSTRING；

 

定义数据

1.tt:root defines data roots for ABAP data interfaces.

2.tt:parameter defines parameters as formal parameters.

3.tt:variable defines variables as local data.

语法：

<tt:root name="..." [[line-]type="..." [length="..."] [decimals="..."]]  [...] />

<tt:parameter name="..." [ref-type="..."] [kind="..."] [[s-val="..."][d-val="..."]]|[val="..."] />

kind：in输入参数；out输出参数；in/out输入输出参数；

s-val,在串行化时有效；d-val,反串行化时有效；val，串行化反串行化都生效；

<tt:variable name="..." [ref-type="..."] [[s-val="..."][d-val="..."]]|[val="..."] />

 

定义模板

<tt:template [name="tmpl"]>  </tt:template>

 

定义引用

<tt:... ref="node">   ...  </tt:...>

 

14.3 ABAP and OLE

语法：

CREATE OBJECT ole class [NO FLUSH] [QUEUE-ONLY].

type group: OLE2;

权限检查Function: AUTHORITY_CHECK_OLE;

语法：

CALL METHOD OF ole meth [= rc]
               [EXPORTING p1 = f1 p2 = f2 ...]
               [NO FLUSH] [QUEUE-ONLY].

 

语法：

GET PROPERTY OF ole attr = dobj [NO FLUSH] [QUEUE-ONLY]   [EXPORTING p1 = f1 p2 = f2 ...].

语法：

SET PROPERTY OF ole attr = dobj [NO FLUSH]  [EXPORTING p1 = f1 p2 = f2 ...].

语法：

FREE OBJECT ole [NO FLUSH].

可以使用ole2方式生成excel。

 

14.4 UUIDS

       使用类CL_SYSTEM_UUID获取UUID。

示例：

FORM f_get_uuid.
  DATA:lo_system_uuid TYPE REF TO if_system_uuid.
  DATA:lv_uuid TYPE sysuuid_c32.
  "创建类对象
  lo_system_uuid = cl_uuid_factory=>create_system_uuid( ).
  TRY.
      lv_uuid = lo_system_uuid->create_uuid_c32( ).
      WRITE:/ lv_uuid.
  CATCH cx_uuid_error.
  ENDTRY.
ENDFORM.