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To develop Java projects with enterprise-scale functionality, you don’t
just need powerful tools and services from your development environment.
An integrated development environment (IDE) must also meet the challenges
and tasks faced by large development teams working from the same code
base — from writing code, to maintaining and updating programs,
to synchronizing development activities and organizing central design
and testing.
To meet these needs, SAP set out to provide
development tools for Java that are not just J2EE-compliant, but that
also offer the robust features on par with what ABAP developers have come
to expect from SAP’s tools in the ABAP Workbench. Now, as of SAP
Web Application Server 6.30, Java developers have SAP NetWeaver Developer
Studio, which offers large development teams full access to all components
of a Java project, tools based on a common framework that makes them easy
to use, and support for combining standard J2EE development tasks with
SAP’s visionary Web Dynpro UI technology (see sidebar).
Filling the Gaps in Traditional J2EE Development Tools
SAP Web Application Server is the application platform for an integrated,
highly scalable business solution environment, and as of Release 6.30,
it provides a development and runtime environment for ABAP applications
and for Java applications based on the J2EE standard.
When it comes to designing applications
and interfaces, the ABAP design-time environment is well established,
having evolved over the past decade, and provides a repository-based approach
that supports development by large teams. The ABAP Workbench is the central
starting point for all ABAP development activities in a distributed development
landscape.
In comparison, Java development is typically
geared to the single developer working at a local frontend, and the J2EE
standard simply leaves integration issues up to the individual tool vendor.
The J2EE standard focuses primarily on the runtime behavior of enterprise-scale
applications written in Java, and takes for granted the existence of J2EE-compliant
development tools. So it’s rare to find a Java IDE that offers solutions
for the typical tasks involved in developing medium- and large-size projects:
 Repository
access: Most Java designtime tools are file based. These tools
typically lack features that developers of large projects with big development
teams have become accustomed to, such as version control and sophisticated
impact analysis.
Support
for central data types: The need to define data types and database
objects in a central location is rarely addressed in today’s J2EE
tools. Most tool vendors simply include a database and corresponding database
tools. But, as a result, Java applications are most likely to be database
dependent.
Advanced
user interface features: J2EE concepts for user interface abstraction
(e.g., modeling and design of interfaces) such as JSP and servlets are
browser dependent — unless you invest a serious amount of code discipline
in your UI projects! In many cases, key functions such as input validation
or value help are missing.
Distributed
development: Large projects must first be tested in a development
landscape before they can be deployed to a productive environment. Pure
J2EE deployment leaves open many issues, such as version control, dependency
analysis, and component support. These issues require the help of a change
management system for keeping track of all deployed development components.
What’s Web Dynpro?
If you’re currently using Java Server Pages (JSP) as the
interface into backend systems, you’ve likely run into concerns
with browser dependencies. SAP’s alternative to browser-dependent
UI programming techniques is Web Dynpro.
Web Dynpro is a model-driven approach to designing user interfaces
that allows you to develop, view, and update your Web UI in a graphical
way. The Web Dynpro approach structures an application into distinct
layers that separate the interface from the backend business logic
to form a highly reusable UI. In fact, the layers are so distinct
that code-specific information is added in a very late phase of
the development process. Web Dynpro also supplies much of the supporting
code in the background automatically, so that you can ensure J2EE
compliance and a complete, accurate UI.1
Web Dynpro for Java is included with Web AS 6.30 and integrated
into the SAP NetWeaver Developer Studio, so you can create Web Dynpro
Java UIs with this current release. For more information on Web
Dynpro, see www.sap.com/technology.
1 See
my article “Your ‘Easy Way In’ to Web Dynpro Development” in
the April-June 2003 issue of SAP Insider
(www.SAPinsider.com)
and the article by Peter Tillert in this issue. |
To address these concerns, SAP has included a robust, integrated Java
IDE in SAP Web Application Server 6.30. SAP NetWeaver Developer Studio
becomes the main entry point for all development activities, offering
developers a window onto a distributed design- and run-time landscape
for J2EE-compliant applications, combining the flexibility of using the
local file system with the reliability and scalability that a centralized
infrastructure can bring.2
Architecture of SAP NetWeaver Developer Studio
When SAP decided to deliver its own development environment, it wasn’t
long before the question came up of whether to embed the SAP tools in
a pre-existing IDE. Most third-party IDEs in the market lacked the openness
and extensibility that SAP sought, so SAP chose to build its tools on
top of Eclipse — an open-source, Java-based development platform.
The Eclipse platform was designed specifically for development of custom
IDEs, and comes with its own J2SE (Java 2 Platform, Standard Edition)
environment for standalone Java applications.
In Eclipse, every extension is called
a plug-in. Each plug-in adds functionality to a given tool at predefined
extension points. What’s more, a plug-in can include its own set
of extension points, so you can even add plug-ins to a plug-in. All development
tools in the SAP NetWeaver Developer Studio — including Web Dynpro,
J2EE, Web services3 (which are built on top of the J2EE perspective),
and the Java Dictionary — are in fact Eclipse plug-ins.4
If Eclipse has any limitations from SAP’s
perspective, they are in modeling the application, presenting logical
hierarchies, or diagramming the application. (This is especially crucial
when it comes to Web Dynpro-based design and technology, where so much
supporting Java code is automatically generated — code that the
typical Java developer probably doesn’t want to see!)
So SAP and Borland jointly developed a
modeling framework based on Eclipse. This framework abstracts from the
physical source files to provide developers with visual models of a program’s
presentation logic. Both Web Dynpro modeling tools and graphical J2EE
tools are based on the same common software layer.5
In fact, all SAP’s Java development
tools are built on top of this modeling framework, resulting in a highly
sophisticated, consistent graphical framework for all kinds of development
activities.
Quick Tour of the Three Major Tools of SAP NetWeaver Developer
Studio
For a first impression of how the SAP NetWeaver Developer Studio operates,
here is a brief introduction to some of the tool sets and perspectives
it offers.
Java Dictionary
We’ll start with the Java Dictionary. The Java Dictionary offers
tools and wizards to define central data types (e.g., enumeration types
for value help) for use in Java projects that will run on Web Dynpro.
You can also create database objects, such as indexes and tables (see
Figure 1), add them to the Java Dictionary, and later
deploy them to your database. The dictionary definitions are stored in
a database-independent fashion, so you can deploy them to all database
platforms officially supported by SAP.6
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Figure 1 |
Java Dictionary |
J2EE Tool Set
SAP NetWeaver Developer Studio offers editors and wizards for creating
all the typical components (e.g., JSP pages and servlets, session beans,
entity beans) of a J2EE-compliant application.7 The J2EE tool
set lets you easily create the Web components of your J2EE applications
by means of JSP and servlet editors, which even offer such fancy features
as syntax-based coloring of code and intellisense (which automatically
completes method names, etc.). The J2EE tools can validate JSP syntax
against the corresponding DTD available over the Internet, and business
logic can be implemented through wizards for Enterprise JavaBeans. J2EE
1.3-compliant session beans, entity beans, and message-driven beans are
all supported.
Web Dynpro Tools
The heart of the Web Dynpro approach is the Application Modeler, which
depicts the various components of your Web UI and their relationships.
Navigational controls are shown as lines that connect Web Dynpro views.
These views in turn contain Web Dynpro controls (input fields, push buttons,
tables, etc.). Web Dynpro technology allows you to quickly assemble views,
even as layouts or data sources change. By relying on a component-based
approach, you will find a high degree of reuse in your Web Dynpro applications.
Additional features of the SAP NetWeaver Developer Studio include:
SAP
Enterprise Connector: The BAPI Browser and Proxy Generator
When you develop your first Java application, you will most likely wish
to connect to an existing SAP database. To call BAPIs from a Java application,
SAP has delivered the Java Connector (JCo). However, JCo is not strongly
typed; to avoid runtime errors, you must check that all data type information
is valid in the parameters of any JCo call.
To overcome this limitation, BAPI Browser
and Proxy Generator let you browse through BAPI lists that include data
type information to help you generate a “type-safe” Java proxy
for use in your Java projects (see Figure 2). The BAPI
Browser uses your SAP Logon files to connect right to existing SAP systems.
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Figure
2 |
BAPI Browser |
Support
for Open SQL
SAP offers tool support
for database-independent access to tables.
This is done by means of an SQLJ precompiler — a
precompiler that translates embedded SQL commands
into plain Java code. Later, during debugging,
the original SQL code is presented directly to the developer so that you
can debug your application rather than the generated code.
Resources
for Team Development
SAP NetWeaver
Developer Studio, with local access via Eclipse,
is also tightly integrated in SAP’s development
infrastructure, which consists of:
- A design-time repository for versioning Java source files
- A component build service that produces runtime objects such as Java
archives
- A change management service to distribute and deploy the Java archives
in a distributed system landscape
In addition, the Developer Studio allows
developers to easily browse through designtime and software components
to view the up-to-date status of development efforts. First, from the
NetWeaver Developer Studio, the development team can view the contents
of the Design Time Repository (DTR) — the repository for development
objects (Java classes, XML sources, etc.) — through a DTR perspective.
From the Development Configurations screen, shown in Figure 3,
you can browse configurations consisting of software components that,
in turn, are made of development components. Development components are
stored centrally in the DTR to ensure consistency and reusability, but
they can also be viewed by a developer locally via Eclipse.
For more on the components that support
the Developer Studio, see Wolf Hengevoss’s article in this issue
of SAP Insider.
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Figure 3 |
Development Configurations Screen |
Summary
SAP’s approach toward an integrated development environment offers
Java developers an environment comparable to that of their ABAP colleagues.
It features a central repository for development objects, and services
that support large teams of developers and enterprise-scale Java projects.
At the heart of SAP’s innovations in this area is the SAP NetWeaver
Developer Studio, which offers full developer access to the project, just
as the Workbench does for the ABAP environment.
What’s more, all the Developer Studio
tools are based on a common framework, making it easy to become familiar
with their features and to combine SAP’s Web Dynpro technology with
standard J2EE development processes.
For more on SAP NetWeaver Developer Studio,
visit www.sap.com/netweaver.
2 To
support this distributed development environment,
the SAP NetWeaver Developer Studio consists
of client-side components, available in 6.30,
and will also offer server-side components
in its infrastructure in 6.40 ' providing
a "best-of-both" approach detailed in Wolf
Hengevoss's article in this issue of SAP
Insider (www.SAPinsider.com).
3 See Martin Huvar's article on Web services
in this issue of SAP Insider (www.SAPinsider.com).
4 For a good look at the SAP NetWeaver Developer
Studio and the Eclipse platform, see Rudi Munz's article in this issue
of SAP Insider (www.SAPinsider.com).
5 Borland also provides extensions to SAP
NetWeaver Developer Studio for models based on the UML standard, the SAP
NetWeaver Developer Studio Together Edition.
6 In this release, SAP's Software Deployment
Manager (SDM) handles deployment. In future releases, it will be carried
out automatically by the Change Management Service (CMS). For more on
these components, see Wolf Hengevoss's article in this issue of SAP
Insider (www.SAPinsider.com).
7 For details on
the structure of J2EE-compliant Java projects,
see my article "Faster and Easier J2EE-Compliant Design
with New Tools from SAP NetWeaver Developer Studio" in
the July 2003 SAP
Insider (www.SAPinsider.com).
Karl Kessler joined SAP in 1992. He is the Product Manager of the ABAP
Workbench and the SAP NetWeaver Developer Studio and is responsible for
all rollout activities. You can reach him via email at karl.kessler@sap.com.
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