Package org.apache.jasper.servlet

Class JspServlet

java.lang.Object

jakarta.servlet.GenericServlet

jakarta.servlet.http.HttpServlet

org.apache.jasper.servlet.JspServlet

All Implemented Interfaces:

Servlet, ServletConfig, Serializable, PeriodicEventListener

public class JspServlet
extends HttpServlet
implements PeriodicEventListener

The JSP engine (a.k.a Jasper). The servlet container is responsible for providing a URLClassLoader for the web application context Jasper is being used in. Jasper will try get the Tomcat ServletContext attribute for its ServletContext class loader, if that fails, it uses the parent class loader. In either case, it must be a URLClassLoader.

Author:

Anil K. Vijendran, Harish Prabandham, Remy Maucherat, Kin-man Chung, Glenn Nielsen

See Also:

• Serialized Form

Field Summary

Fields inherited from class jakarta.servlet.http.HttpServlet

LEGACY_DO_HEAD

Constructor Summary

Constructors

Constructor	Description
JspServlet()

Method Summary

Modifier and Type	Method	Description
void	destroy()	Called by the servlet container to indicate to a servlet that the servlet is being taken out of service.
int	getJspCount()	Returns the number of JSPs for which JspServletWrappers exist, i.e., the number of JSPs that have been loaded into the webapp with which this JspServlet is associated.
int	getJspQueueLength()	Gets the number of JSPs that are in the JSP limiter queue
int	getJspReloadCount()	Gets the number of JSPs that have been reloaded.
int	getJspUnloadCount()	Gets the number of JSPs that have been unloaded.
void	init(ServletConfig config)	Called by the servlet container to indicate to a servlet that the servlet is being placed into service.
void	periodicEvent()	Execute a periodic task, such as reloading, etc.
void	service(HttpServletRequest request, HttpServletResponse response)	Receives standard HTTP requests from the public service method and dispatches them to the doMethod methods defined in this class.
void	setJspReloadCount(int count)	Resets the JSP reload counter.

Methods inherited from class jakarta.servlet.http.HttpServlet

doDelete, doGet, doHead, doOptions, doPatch, doPost, doPut, doTrace, getLastModified, isSensitiveHeader, service

Methods inherited from class jakarta.servlet.GenericServlet

getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

JspServlet

public JspServlet()

Method Details

init

public void init(ServletConfig config)
          throws ServletException

Description copied from class: jakarta.servlet.GenericServlet

Called by the servlet container to indicate to a servlet that the servlet is being placed into service. See Servlet.init(jakarta.servlet.ServletConfig).

This implementation stores the ServletConfig object it receives from the servlet container for later use. When overriding this form of the method, call super.init(config).

Specified by:

init in interface Servlet

Overrides:

init in class HttpServlet

Parameters:

config - the ServletConfig object that contains configuration information for this servlet

Throws:

ServletException - if an exception occurs that interrupts the servlet's normal operation

See Also:

• UnavailableException

getJspCount

public int getJspCount()

Returns the number of JSPs for which JspServletWrappers exist, i.e., the number of JSPs that have been loaded into the webapp with which this JspServlet is associated.

This info may be used for monitoring purposes.

Returns:

The number of JSPs that have been loaded into the webapp with which this JspServlet is associated

setJspReloadCount

public void setJspReloadCount(int count)

Resets the JSP reload counter.

Parameters:

count - Value to which to reset the JSP reload counter

getJspReloadCount

public int getJspReloadCount()

Gets the number of JSPs that have been reloaded.

This info may be used for monitoring purposes.

Returns:

The number of JSPs (in the webapp with which this JspServlet is associated) that have been reloaded

getJspQueueLength

public int getJspQueueLength()

Gets the number of JSPs that are in the JSP limiter queue

This info may be used for monitoring purposes.

Returns:

The number of JSPs (in the webapp with which this JspServlet is associated) that are in the JSP limiter queue

getJspUnloadCount

public int getJspUnloadCount()

Gets the number of JSPs that have been unloaded.

This info may be used for monitoring purposes.

Returns:

The number of JSPs (in the webapp with which this JspServlet is associated) that have been unloaded

service

public void service(HttpServletRequest request,
 HttpServletResponse response)
             throws ServletException,
IOException

Description copied from class: jakarta.servlet.http.HttpServlet

Receives standard HTTP requests from the public service method and dispatches them to the doMethod methods defined in this class. This method is an HTTP-specific version of the Servlet.service(jakarta.servlet.ServletRequest, jakarta.servlet.ServletResponse) method. There's no need to override this method.

Overrides:

service in class HttpServlet

Parameters:

request - the HttpServletRequest object that contains the request the client made of the servlet

response - the HttpServletResponse object that contains the response the servlet returns to the client

Throws:

ServletException - if the HTTP request cannot be handled

IOException - if an input or output error occurs while the servlet is handling the HTTP request

See Also:

• Servlet.service(jakarta.servlet.ServletRequest, jakarta.servlet.ServletResponse)

destroy

public void destroy()

Description copied from class: jakarta.servlet.GenericServlet

Called by the servlet container to indicate to a servlet that the servlet is being taken out of service. See Servlet.destroy().

Specified by:

destroy in interface Servlet

Overrides:

destroy in class GenericServlet

periodicEvent

public void periodicEvent()

Description copied from interface: PeriodicEventListener

Execute a periodic task, such as reloading, etc.

Specified by:

periodicEvent in interface PeriodicEventListener