Technology for SOA

As we discussed earlier, SOA is an approach and tells us nothing about which technology to use to implement it. Each organization is free to choose the desired technology as long as it ensures the SOA principles.

The most common implementation is based on the following standards:

• XML: This is the extensible markup language we all know. It is the typical language used to model the organization's business entities; another option quite popular nowadays is JSON.
• HTTP(s): This is the protocol used to exchange information between systems.
• SOAP: Simple Object Access Protocol (SOAP), is based on XML and defines the structure that will be used to exchange information between systems. A SOAP message contains the following elements:

Based on the experience of working with WSO2 products for more than five years, we have to follow how the company has grown and expanded due to its innovative culture. Along with this experience, we have witnessed the evolution of the WSO2 components since the successful early version of the ESB and DSS to the current ones, and the brand new WSO2 EI.

In the following chart from the WSO2 site, we can see the WSO2 vision of the SOA infrastructure:

We have already discussed all these components in the preceding figure about the WSO2 SOA infrastructure, except WSO2 Application Server. WSO2 Application Server, as the name says, is a Java application container for web applications, web services, and RESTful services. This container is called the Carbon platform. According to the level of this book, we will focus on the following WSO2 EI functionalities:

• Service Integration
• Data Integration
• Messaging
• Analytics
• Tooling

In the subsequent chapters, we will learn how to install WSO2 EI, create web services and data services, and how to test and manage them. We will also learn how to build services that use message queues, data services, and connectors to integrate with third-party applications.