Adapters:

                         By developing a BPEL Process we need to interact with Database or to read or write a file from local system(File Adapter), or we read or write a file from existing system(FTP).For such sort of situations we used Adapters. JDeveloper as provided us with good number of Adapters, through these Adapters we can easily interact with the existing environment.

                          Once we created a Adapter, it automatically generates XML Schema, as  XML understood by all environments. Interaction between different environments become very easy.

Adapters support a robust, light-weight, highly scalable and standards-based integration framework,which enables disparate applications to communicated with each other. They are used to integrate packaged applications, legacy applications, databases, and webservices.

The Following types of technology adapters are available in JDeveloper.

• File/FTP Adavpter
• Database Adapter
• Oracle Apps Adapter
• AQ Adapter
• MQ Adapter
• JMS Adapter

File/FTP Adapter

The File Adapter work with Oracle BPEL Process Manager and Oracle Mediator, to interact with local File system directories.The FTP Adapters enables to configure the BPEL/Mediator, to interact with remote file system directories.The File/FTP Adapters are basically used to read , write files locally/remotely on your system/existing system.

There are mainly 4 operations in FILE adapter namely:

• READ: It is an inbound operation that reads a file from given directory path.
• WRITE: It is an Outbound operation to write files to a location specified under directory path.
• SYNCHRONOUS READ: It is Outbound operation used to read a file in middle of the process. In this we can't give poling frequency.
• LIST FILE: It is Outbound Operation to list all the files in a given directory.or it get you the list of file names, it didn't give you file content.

The file and FTP adapters can read and write the following file formats and use the adapter translator component at both design time and run time

·         XML (both XSD- and DTD-based)

·         Delimited(Contains records whose fields are delimited by a special character)

·         Fixed Length(Contains records whose fields are fixed in length)

·      Complex Type(Contains records whose fields may themselves be records having multiple delimiter types)

·         COBOL Copybook data

It can also treat file contents as an opaque object.

For inbound file, the file and FTP adapters perform the following operations 

·         Poll the file system looking for matches

·         Read and translate the file contents based on the translation logic defined at design time

·         Publish the same as an XML message

For outbound files sent from Oracle BPEL Process Manager/Mediator, the file and FTP adapters perform the following operations 

·         Receive messages from BPEL/Mediator

·         Format the XML contents as specified at design time

·         Produce output files

For inbound file and FTP adapters have parameters for the inbound directory where the input file appears, the file naming pattern and the frequency with which to poll the directory.

Database Adapter:

The Database Adapter enables to interact with standard Database/oracle Dbase/Third party Database through JDBC.

The following operations are supported in the Database adapter

• Call a stored procedure or a function.
• Perform a table operation which can be one of the following.

                   Insert only

                   Update Only

                   Insert or Update

                   Update

                   Select 

• Poll for new or changed records in a table
• Execute Custom SQL

Before connecting to a database through the database adapter, the database connection must be created and configured for that particular database using the Database Connection Wizard.

Oracle Applications Adapter:

The Oracle Application Adapter enables to interact with various interfaces of an oracle Application instance that is hosted in a given database connection.It offers support for open interface imports, and other such things that can be done in the Oracle Apps. It offers a rich set of  object invocation which includes concurrent programs, XML gateway, EDI sources, business events apart form tables, views and APIs which can be invoked even through the database adapter.

AQ(Advanced Queuing) Adapter:

           AQ is Oracle Advanced queuing  provides a flexible mechanism for bidirectional, it provides the message management functionality and asynchronous communication needed for application integration.

              AQ are an Oracle database feature, and are therefore scalable and reliable,Other features of Oracle dbase, such as backup and recovery,logging, transactional services.Multiple queues can also service a single application. AQ only interacts with database queues because it resides in database.The enqueue operation is outbound while the dequeue operation is inbound thus the AQ adapter is both the producer and consumer of the AQ messages.Specify the operation whether it is an Enqueue or Dequeue and the queue name from which the message is to be enqueued or dequeued

     (or) 

               Oracle AQ provides database-integrated message queuing functionality. It is built on top of Oracle Streams and optimizes the functions of Oracle Database so that messages can be stored persistently, propagated between queues on different computers and databases, and transmitted using Oracle Net Services, HTTP, and HTTPS. Because Oracle AQ is implemented in database tables, all operational benefits of high availability, scalability, and reliability are also applicable to queue data.

MQ: AQ is a Oracle implementation of their Queue messaging; Advanced Queueing. The same has IBM with their MQ and like others. These implemenations are specific of the Vendors.

JMS(Java Messaging System) Adapter:

         JMS resides in Application Server(Web logic). JMS can interact with database queues as well as in memory/file or queue's outside.

       The JMS API is a messaging standard that allows application components based on the Java 2 Platform, Enterprise Edition to create, send, receive, and read messages. It enables distributed communication that is loosely coupled, reliable, and asynchronous.