Building Web Services

In this chapter, we will look at the main concepts of WSO2 Enterprise Integrator. What is the nomenclature and the parts that have a role inside different types of services that offer us the EI server:

• How to build SOAP Proxies and REST APIs
• Creation of inbound endpoints for dynamic services
• Different mediators such as send, log, script, and property
• Transport configuration
• Creation and configuration of sequences
• Scheduling tasks

WSO2 EI has multiple entry types to start a service:

• Proxy: Acts as a virtual service: receives messages and mediates them before sending them to the endpoint
• Main Sequence: Default sequence for all messages not sent to a proxy service
• API: Accepts REST messages that allow clients to provide additional information on how to manage the message
• Inbound Endpoint: A message source that can be configured dynamically
• Task: Scheduled jobs to execute proxy service or a named sequence

When we create a service, it's necessary to configure the following:

• Transport: Carry the payload in a specific format
• Mediators: Simplest message processing units that are placed inside sequences
• Sequences: List of mediators executed sequentially
• Endpoints: Define destination for the current payload