Interface JspPage

All Superinterfaces:
jakarta.servlet.Servlet
All Known Subinterfaces:
HttpJspPage
public interface JspPage extends jakarta.servlet.Servlet
The JspPage interface describes the generic interaction that a JSP Page Implementation class must satisfy; pages that use the HTTP protocol are described by the HttpJspPage interface.

Two plus One Methods

The interface defines a protocol with 3 methods; only two of them: jspInit() and jspDestroy() are part of this interface as the signature of the third method: _jspService() depends on the specific protocol used and cannot be expressed in a generic way in Java.

A class implementing this interface is responsible for invoking the above methods at the appropriate 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.

_jspService()

The _jspService()method corresponds to the body of the JSP page. This method is defined automatically by the JSP container and should never be defined by the JSP page author.

If a superclass is specified using the extends attribute, that superclass may choose to perform some actions in its service() method before or after calling the _jspService() method. See using the extends attribute in the JSP_Engine chapter of the JSP specification.

The specific signature depends on the protocol supported by the JSP page. 

 public void _jspService(ServletRequestSubtype request,
                             ServletResponseSubtype response)
        throws ServletException, IOException;

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    jspDestroy()
    The jspDestroy() method is invoked when the JSP page is about to be destroyed.
    void
    jspInit()
    The jspInit() method is invoked when the JSP page is initialized.

    Methods inherited from interface jakarta.servlet.Servlet

    destroy, getServletConfig, getServletInfo, init, service

  • Method Details

    • jspInit

      void jspInit()
      The jspInit() method is invoked when the JSP page is initialized. It is the responsibility of the JSP implementation (and of the class mentioned by the extends attribute, if present) that at this point invocations to the getServletConfig() method will return the desired value.

      A JSP page can override this method by including a definition for it in a declaration element.

      A JSP page should redefine the init() method from Servlet.

    • jspDestroy

      void jspDestroy()
      The jspDestroy() method is invoked when the JSP page is about to be destroyed.

      A JSP page can override this method by including a definition for it in a declaration element.

      A JSP page should redefine the destroy() method from Servlet.