org.apache.felix.webconsole.servlet

Class AbstractServlet

java.lang.Object

jakarta.servlet.GenericServlet

jakarta.servlet.http.HttpServlet

org.apache.felix.webconsole.servlet.AbstractServlet

All Implemented Interfaces:

jakarta.servlet.Servlet, jakarta.servlet.ServletConfig, java.io.Serializable

public abstract class AbstractServlet
extends jakarta.servlet.http.HttpServlet

This class can be used as a base class for a web console plugin. The plugin (servlet) needs to be registered as a servlet service with at least the label property.

Extending this servlet is one way of providing a plugin. The other is to simply direclty implement the servlet interface. In both cases requests to resources with a path of "LABEL/res/*" are automatically handled.

For html (content) requests, the web console automatically renders the header, footer and navigation.

Support for Jakarta servlets requires that the Jakarta Servlet API and the Apache Felix Http Wrappers are available in the runtime.

If you are upgrading from AbstractWebConsolePlugin there are some changes to be aware of:

• Resources are detected via the getResource(String) method.
• Regardless of the http method, if the corresponding doXXX method does not create a response, the renderContent(HttpServletRequest, HttpServletResponse) method is invoked.
• If a doXXX method other than doGet wants to create a response, it must not call doGet or renderContent directly. It rather just does not create any response and returns. In this case the web console will invoke the renderContent method afterwards.

See Also:

ServletConstants.PLUGIN_LABEL, ServletConstants.PLUGIN_TITLE, ServletConstants.PLUGIN_CATEGORY, ServletConstants.PLUGIN_CSS_REFERENCES, Serialized Form

Constructor Summary

Constructors

Constructor and Description
AbstractServlet()

Method Summary

Modifier and Type	Method and Description
void	renderContent(jakarta.servlet.http.HttpServletRequest request, jakarta.servlet.http.HttpServletResponse response) This method is used to render the main contents of the plugin
static void	setNoCache(jakarta.servlet.http.HttpServletResponse response) Sets response headers to force the client to not cache the response sent back.

Methods inherited from class jakarta.servlet.http.HttpServlet

service

Methods inherited from class jakarta.servlet.GenericServlet

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

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractServlet

public AbstractServlet()

Method Detail

renderContent

public void renderContent(jakarta.servlet.http.HttpServletRequest request,
                          jakarta.servlet.http.HttpServletResponse response)
                   throws jakarta.servlet.ServletException,
                          java.io.IOException

This method is used to render the main contents of the plugin

Parameters:

request - The request

response - The response

Throws:

jakarta.servlet.ServletException - If an error occurs

java.io.IOException - If writing the response fails

setNoCache

public static final void setNoCache(jakarta.servlet.http.HttpServletResponse response)

Sets response headers to force the client to not cache the response sent back. This method must be called before the response is committed otherwise it will have no effect.

This method sets the Cache-Control, Expires, and Pragma headers.

Parameters:

response - The response for which to set the cache prevention