11 Using Converters, Listeners, and Validators

The previous chapter described components and explained how to add them to a web page. This chapter provides information on adding more functionality to the components through converters, listeners, and validators.

• Converters are used to convert data that is received from the input components. Converters allow an application to bring the strongly typed features of the Java programming language into the String-based world of HTTP servlet programming.

• Listeners are used to listen to the events happening in the page and perform actions as defined.

• Validators are used to validate the data that is received from the input components. Validators allow an application to express constraints on form input data to ensure that the necessary requirements are met before the input data is processed.

The following topics are addressed here:

• Using the Standard Converters

• Registering Listeners on Components

• Using the Standard Validators

• Referencing a Managed Bean Method