Adding UI Code
You can add UI code to the task flow by using managed beans.
Managed beans are Java classes with a no-argument constructor that you register with the application in task flow .xml files. When the JSF application starts up, it parses these files and makes the beans available to be referenced in EL expressions (you learn about these in the lesson titled “Implementing Transactional Capabilities”) or Java code, enabling access to the beans’ properties and methods.
Whenever a managed bean is referenced for the first time and it does not already exist, the Managed Bean Creation Facility instantiates the bean by calling the default constructor method on the bean. If any properties are also declared, they are populated with the declared default values.