There are two types of validation that can occur when you are working with source files in a structured source editor: source validation and batch validation.
<foo:bar>
where foo:baris a tag that does not exist, the problem would be discovered immediately and would appear underlined in the editor. The advantage of this type of validation is that it can alert you to errors instantly.
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h"%>
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h"%>
Batch validation can uncover errors in multiple files at once and give you a comprehensive view of where problematic code can be found in your project. Moreover, you do not need to open files in an editor to run batch validation. To run batch validation on specific files, select and right click the files in the Project Explorer and then select
from the popup menu.