mastanikДело в том, что я писал бакалаврскую работу на тему: "Интеграция корпоративных приложений на основе J2EE платформы". И мне нужны были примеры интеграции, на которых я бы мог показать методы с помощью которых достигается интграция.
Data-level EAI is the process—and thechniques and technology—of moving data
between data stores. This can be described as extracting information from one
database, perhaps processing that information as needed, and updating it in another
database. While this sounds direct and straightforward, in a typical EAI-enabled
enterprise, it might mean drawing from as many as one hundred databases and several
thousands of tables. It may also include the transformation and application of business
logic to the data that is being extracted and loaded.
The advantage of data-level EAI is the cost of using this approach. Because we are
largely leaving the application alone, and not changing code, we don't need to incur
the expense of changing, testing, and deploying the application. What's more, the
technology that provides mechanisms to move data between databases, as well as
reformats that information, is relatively inexpensive considering the other EAI levels
and their applicable enabling technology.
The approach and enabling technology you leverage depends on the requirements of
the problem domain.

Application interface-level EAI refers to the leveraging of interfaces exposed by
custom or packaged applications. Developers leverage these interfaces to access both
business processes and simple information. Using these interfaces, developers are able
to bundle many applications together, allowing them to share business logic and
information. The only limitations that developers face are the specific features and
functions of the application interfaces.
This type of EAI is most applicable to packaged applications such as SAP, PeopleSoft,
and Baan, which all expose interfaces into their processes and data, but do so in very
different ways. In order to integrate those systems with others in the enterprise, we
must use these interfaces to access both processes and data, extract the information,
place it in a format understandable by the target application, and transmit the
information. While many different types of technologies can do this, message brokers
seem to be the preferred solution.

Method-level EAI is the sharing of the business logic that may exist within the
enterprise. For example, the method for updating a customer record may be accessed
from any number of applications, and applications may access each other's methods
without having to rewrite each method within the respective application.
The mechanisms to share methods among applications are numerous, including
distributed objects, application servers, TP (transaction processing) monitors,
frameworks, and simply creating a new application that's the combination of two or
more applications. There are two basic approaches: You may create a shared set of
application servers that exist on a shared physical server, such as an application server,
or you may share methods already existing inside of applications using distributed
method-sharing technology such as distributed objects.
Method-level EAI is something we've been practicing for years as we sought to reuse
application development efforts within the enterprises. We've not been largely
successful due to both human and technological issues. Perhaps with EAI, we may get
it right.

User interface-level EAI is a more primitive, but nonetheless necessary, approach.
Using this scenario, architects and developers are able to bundle applications by using
their user interfaces as a common point of integration (also known as screen scraping).
For example, mainframe applications that do not provide database- or business
process-level access may be accessed through the user interface of the application.
Although many consider leveraging the user interface as a point of integration to be
an unstable and archaic approach, the fact is that we've been doing this for years and
have worked out many of the issues, such as performance, reliability, and scalability.
Although not preferred, it may be the only solution you have in many instances.
Remember, EAI at its heart is the ability to leverage any existing system by finding a
reliable point-of-integration. Existing 3270 interface middleware that is typically
bundled with emulators is an enabling technology to serve user interface-level EAI.