SPRING ENTERPRISE INTEGREATION TRAINING

• Messages: The data is transferred from one place to another. They are the comprise of a header and a payload.
• Channels: In channels, messages are transferred from one endpoint to another. There are two types of channels in Spring Integration. They are Pollable channel and Subscribable channels.
• Endpoints: Consumer or Producer of messages does various actions on the payload. Endpoints come in various flavors, each performing different functions.

Adapters are classified into two types. They are Inbound and outbound.

• Inbound adapters: Inbound adapters are used to bring the messages into the Spring Integration channels.
• Outbound adapters: Outbound adapters are used to get messages from Spring Integration channels to the outside applications, database, etc.

• Spring Integration filters are also called as end points which is the connection between the channels. This is used to allow or reject the messages from one message channel to other.
• Filters allow some messages to pass from one channel to other channel.
• The messages that are not selected are deleted permanently.
• By taking message payload or message metadata into consideration only the selection is done.
• While transferring from one channel to other channel either acceptance of a message or rejection of a message is done.
• It also provides several ready-to-use filters with the framework.

• The payload or structured messages is converted into the modified message by Transformers.
• Spring Integration consists of a number of built-in transformers.
• In Spring Integration XML payload to Object payload is called as unmarshallers.
• Object message transformation to XML message transformation is called as marshallers.

• Routers are also called as message distribution components.
• Spring Integration Routers receive messages from one channel and distributes the messages to one or more than one channels.
• Some of the routers will identify where to deliver the message.
• Some routers distribute the messages to all the receiving channels.
• Content routers identify the content of the incoming message and use the payload type or header value to determine which channel receives the message.
• Recipient list routers need not be identify the message.
• Incoming messages are transferred to all the listed recipient channels.

• Enrichers play a very important role in Spring Integration.
• Information or content to a Spring Integration message is added by Enrichers.
• Channel messages are received by Enricher.
• Enricher adds data or information to the message’s header or payload and transfer the message to another channel.
• Enrichers are considering different types of transformers.

• For connecting a spring object or bean to a message channel, service activator is used as a message endpoint.
• The object or bean acts as Service.
• When the message enters into the channel than only the service is activated.
• If the results are produced by the services than the output is sent to an output channel.
• Every Service activator must associate to the service beam.

• To a Spring Integration system, Spring Integration Gateway acts as façade.
• From the application, Spring Integration Gateways hides Spring Integration Application Programming Interface (SI API).
• Gateway is explained by an interface.