ABAP is the programming interface of
Application Server ABAP (AS ABAP) in SAP NetWeaver. Prerequisite for the use of the ABAP programming
language is the installation of an Application Server ABAP. Most of the components of an AS ABAP can
be organized according to their tasks in the layers of a three-tier client-server architecture with presentation, application, and database layers.
The presentation layer is distributed to the workstations of individual users and represents the user interface of an AS ABAP (
SAP GUI or Web browser).
This is the classical functional interface of AS ABAP. A Remote Function Call is a call of a function
in a system other than the one in which the calling program is running. Calls are possible between different
AS ABAPs or between an AS ABAP and an external system. On AS ABAP, the functions are realized in function
modules. In external systems, specially programmed functions are called whose interface simulates a function module.
Internet Communication Manager is a process of AS ABAP that enables AS ABAP to communicate directly with the Internet using HTTP/HTTPS/SMTP. ICM is used to connect Web-based presentation components such as
Web Dynpro ABAP, and
BSP. ICM also enables an AS ABAP
to be used both as a client and as a server for Web services. ICM is accessed from within ABAP programs using the classes and interfaces of
Internet Communication Framework (ICF).
ABAP Channels are a framework for event-based communication between application servers and the Internet.
ABAP Messaging Channels (AMC) are used to exchange messages between ABAP programs on different application servers.
ABAP Push Channels (APC),
on the other hand, enable bidirectional communication between AS ABAP and the Internet using the WebSocket protocol or the TCP socket protocol.
The main role of ABAP programs in the application layer is the processing and formatting of data from
the database layer and its transfer to and receipt of input from the presentation layer or the communication components.
ABAP Objects is the recommended approach for both new projects and when redesigning existing projects.
One of the fundamental properties of ABAP as a programming language for business applications is that access to database tables is fully integrated into the language.
ABAP data modeling makes it possible to create data models for business applications that have variants on the database:
is a persistent repository for data types and their dependencies. They are visible and can be used in all other development objects. ABAP Dictionary manages the database tables, views, and lock objects in the
standard AS ABAP database.
Access to data in database tables is fully integrated in ABAP:
Open SQL makes it possible to access database objects defined in ABAP Dictionary or ABAP CDS with automatic
client handling. This access is cross-platform and integrated into the language. The performance can be optimized using the
table buffering integrated into the ABAP runtime environment.
Native SQL makes platform-specific access to databases possible. Here,
ADBC enables general class-based access to databases.
AMDP can be used to manage and call database procedures and database functions from the
SAP HANA database.
ABAP is a 4GL language developed specifically for the mass processing of data in business applications.
Alongside integrated database access, it offers the following characteristics when compared with elementary languages (where these functions are usually stored in libraries):
Internal tables for dynamic storage and processing of mass table data in the working memory.
The integration of these functions into the language is a particular benefit for the static check-enablement
and performance of programs. In return, this means that ABAP also contains considerably more language elements than an elementary programming language.
The multilingual capability of ABAP programs is enabled by the extraction of language-specific program components from the source code, which are then reloaded when the program executes in accordance with the environment. A
text environment determines the precise program behavior at runtime, for example the order in which text is sorted.