The javax.servlet.jsp Package - Developing Java Servlets - page 485

The _jspService method corresponds to the body of the JSP page. It is defined automatically
by the JSP processor and should never be redefined by the JSP author. It returns no value.

It has two parameters:

• HttpServletRequest
• HttpServletResponse

It throws these exceptions:

• javax.servlet.ServletException
• java.io.IOException

The JspPage Interface
public interface JspPage extends javax.servlet.Servlet

This is the interface that a JSP processor-generated class must implement.

This interface defines a protocol with three methods; only two of them, jspInit() and
jspDestroy() , are part of this interface. The signature of the third method, _jspService() ,
depends on the specific protocol used and cannot be expressed in a generic way in Java.

D

A class implementing this interface is responsible for invoking these methods at the appropri-
ate time based on the corresponding Servlet-based method invocations.

The jspInit() and jspDestroy() methods can be defined by a JSP author, but the
_jspService() method is defined automatically by the JSP processor based on the contents of
the JSP page.

The jspInit() Method
public void jspInit()

The jsp_init() method is invoked when the JspPage is initialized. After the JspPage is ini-
tialized, the getServletConfig() method will return the desired value. jsp_init() is synony-
mous with the init() method of a servlet.

It has no parameters, returns no value, and throws no exceptions.

The jspDestroy() Method
public void jspDestroy()

The jspDestroy() method is invoked when the JspPage is about to be destroyed. It is synony-
mous with the destroy() method of a servlet.

It has no parameters, returns no value, and throws no exceptions.