The Spring Integration Tutorial

Tutorial Structure / Ideas

There are numreous ways we can develop a tutorial for Spring Integration and Spring Batch. I think the tutorial should be a continuation of the [Spring MVC Tutorial] (https://github.com/joshlong/the-spring-tutorial).

Basically, we have a Customer Relationship Manager (CRM) application that will be extended to provide the following 2 use-cases:

1. When users/customers are added, retrieve additional data from an external systems (using Spring Integration), e.g. (suggestion):

• Convert (geocode) address information into Latitude/Longitude coordinates using WS/REST calls
• Calculate periodically or upon event (e.g. user added) agregate data points, e.g. how many customer are in the same Zip/Postal Code. Trigger (Email) notifications, once certain thresholds are exceeded - e.g. more than 5 customers exist in the same ZIP/Postal Code
• Do a periodic data export and transfer the data via SFTP to a remote server

2. Provide a bulk-data import feature (utilizing Spring Batch). E.g. a CSV file, containing customer information is droped into a directory and we must pick it up, process and import the data.

It looks like we could utilize http://beta.generatedata.com/ to generate interesting sets of sample data.

3. As an adavanced chapter, we could demonstrate how to modularize portions of the application, e.g. using RabbitMQ

• Take a look at Mark Fisher's Spring One demo: https://github.com/markfisher/springone-wgrus/tree/master/modular

To outline some of the contents, I have been using my 2012 SpringOne presentation.

Overview of the Tutorial

Over the course of this tutorial, you will learn how to use Spring Integration. We will show how to use Spring Integration to connect and integrate with external systems but we will also show how you can use Spring Integration as an Intra Application Framwork in order to improve maintainability and scalaiblity.

Furthermore, we will implement a use-case to handle the processing of large files using Spring Batch.

Introduction to Spring Integration

• Light-weight messaging framework
• Provides an adapter-based platform

Common Patterns

1. Retrieve
2. Parse
3. Transform
4. Transmit

Enterprise Integration Patterns

Pipes and Filters at the core of Spring Integration’s architecture

• Endpoint (Filter)
• Channel (Pipe)
• Message

What is in a Message?

• Structure of a Message
  • Headers
  • Payload
• Function of a Message
  • Document Message
  • Command Message
  • Event Message

What is a Channel?

What is an Endpoint?

Common Enterprise Integration Patterns

Router

Transformer

...

Why would I care?

Provides building blocks to implement systems that:

• are loosely Coupled (Logically or Physically)
• are Event Driven (EDA)
• have a staged event-driven architecture (SEDA)

Sophisticated support for synchronous / asynchronous messaging

Integration Styles

• Business to Business Integration (B2B)
• Inter Application Integration
• Intra Application Integration

Deployment Options

• Embedded as a library
• Stand-alone deployment
• War deployment

Spring Integration Components and Adapters

Spring Integration provides many components...

Build a first Spring Integration Application

Not sure how this could changed to provide a better flow with the CRM sample application. Right at this point I would like to demonstrate the most simple Spring Integration Hello World example. The example below basically representst one of the Spring Integration STS templates.

User enters String, which will passed to the Gateway and the Transformer will convert the String to upper-case and the upper-case String is returned to the user.

1. Gateway
2. Request Channel
3. Transformer

• Explain the Gateway

• Explain Request Channel

• Explain the Transformer

• Explain that sometimes different component can accomplish the same task. Choose the component that fits functionally and semantically. E.g. instead of a Transformer you can use a Service Activator.

• Show a very explicit sample first, e.g. with channels defined. Explained which elements are created implicitly, e.g. leave off the channels.

The Channel Deep-Dive

• Direct Channel (Single Thread)
• Queue Channels

Pollers

Pollers are used in both inbound and outbound messaging scenarios. Here are some use-cases that illustrate the scenarios in which Pollers are used:

• Polling certain external systems such as FTP Servers, Databases, Web Services
• Polling internal (pollable) Message Channels
• Polling internal services (E.g. repeatedly execute methods on a Java class)

Integration with External Systems (Sample)

This should probably be some more involved example using either the Twitter adapters or some other web-service to retrieve data (ideally retrieve data from multiple source) Aggregate them, process them and ultimately send them some place else (e.g. email)

Modularizing the CRM Application

TBD

Spring Batch

Overview

TBD

Integration Options between Spring Batch and Integration

Illustrate functionality provided by the Spring Batch Integration module: https://github.com/SpringSource/spring-batch-admin/tree/master/spring-batch-integration

The Sample

• Add flat-file import capabilities to the CRM application.