Package javax.portlet

Class GenericPortlet

  • All Implemented Interfaces:
    Portlet
    public abstract class GenericPortlet
extends Object
implements Portlet
    The GenericPortlet class provides a default implementation for the Portlet interface. It provides an abstract class to be subclassed to create portlets. A subclass of GenericPortlet should override at least one method, usually one of the following:
    • processAction, to handle action requests
    • doView, to handle render requests when in VIEW mode
    • doEdit, to handle render requests when in EDIT mode
    • doHelp, to handle render request when in HELP mode
    • init and destroy, to manage resources that are held for the life of the servlet
    Normally there is no need to override the render or the doDispatch methods. Render handles render requests setting the title of the portlet in the response and invoking doDispatch. doDispatch dispatches the request to one of the doView, doEdit or doHelp method depending on the portlet mode indicated in the request. Portlets typically run on multithreaded servers, so please note that a portlet must handle concurrent requests and be careful to synchronize access to shared resources. Shared resources include in-memory data such as instance or class variables and external objects such as files, database connections, and network connections.
    Version:
    $Revision: 5441 $
    Author:
    Julien Viet

    • Constructor Detail

      • GenericPortlet

        protected GenericPortlet()
        Does nothing.

    • Method Detail

      • init

        public void init()
          throws PortletException
        A convenience method which can be overridden so that there's no need to call super.init(config).

        Instead of overriding init(PortletConfig), simply override this method and it will be called by GenericPortlet.init(PortletConfig config). The PortletConfig object can still be retrieved via getPortletConfig().

        Throws:
        PortletException - if an exception has occurred that interferes with the portlet normal operation.
        UnavailableException - if the portlet is unavailable to perform init

      • getPortletConfig

        public PortletConfig getPortletConfig()
        Returns the PortletConfig object of this portlet.
        Returns:
        the PortletConfig object of this portlet

      • getPortletContext

        public PortletContext getPortletContext()
        Returns the PortletContext of the portlet application the portlet is in.
        Returns:
        the portlet application context

      • getResourceBundle

        public ResourceBundle getResourceBundle​(Locale locale)
        Gets the resource bundle for the given locale based on the resource bundle defined in the deployment descriptor with resource-bundle tag or the inlined resources defined in the deployment descriptor.
        Returns:
        the resource bundle for the given locale

      • getTitle

        protected String getTitle​(RenderRequest request)
        Used by the render method to get the title. The default implementation gets the title from the ResourceBundle of the PortletConfig of the portlet. The title is retrieved using the 'javax.portlet.title' resource name. Portlets can overwrite this method to provide dynamic titles (e.g. based on locale, client, and session information). Examples are:
        • language-dependant titles for multi-lingual portals
        • shorter titles for WAP phones
        • the number of messages in a mailbox portlet
        Returns:
        the portlet title for this window

      • getInitParameter

        public String getInitParameter​(String name)
                        throws IllegalArgumentException
        Returns a String containing the value of the named initialization parameter, or null if the parameter does not exist.
        Parameters:
        name - a String specifying the name of the initialization parameter
        Returns:
        a String containing the value of the initialization parameter
        Throws:
        IllegalArgumentException - if name is null.

      • getInitParameterNames

        public Enumeration getInitParameterNames()
        Returns the names of the portlet initialization parameters as an Enumeration of String objects, or an empty Enumeration if the portlet has no initialization parameters.
        Returns:
        an Enumeration of String objects containing the names of the portlet initialization parameters, or an empty Enumeration if the portlet has no initialization parameters.

      • init

        public void init​(PortletConfig config)
          throws PortletException
        Called by the portlet container to indicate to a portlet that the portlet is being placed into service. The default implementation just stores the PortletConfig object.

        The portlet container calls the init method exactly once after instantiating the portlet. The init method must complete successfully before the portlet can receive any requests.

        The portlet container cannot place the portlet into service if the init method does one of the following:

        1. it throws a PortletException
        2. it does not return within a time period defined by the Web server
        Specified by:
        init in interface Portlet
        Parameters:
        config - a PortletConfig object containing the portlet configuration and initialization parameters
        Throws:
        PortletException - if an exception has occurred that interferes with the portlet normal operation.
        UnavailableException - if the portlet cannot perform the initialization at this time.

      • processAction

        public void processAction​(ActionRequest request,
                          ActionResponse response)
                   throws PortletException,
                          PortletSecurityException,
                          IOException
        Called by the portlet container to allow the portlet to process an action request. This method is called if the client request was originated by a URL created (by the portlet) with the RenderResponse.createActionURL() method. The default implementation throws an exception.
        Specified by:
        processAction in interface Portlet
        Parameters:
        request - the action request
        response - the action response
        Throws:
        PortletException - if the portlet cannot fulfilling the request
        UnavailableException - if the portlet is unavailable to process the action at this time
        PortletSecurityException - if the portlet cannot fullfill this request because of security reasons
        IOException - if the streaming causes an I/O problem

      • destroy

        public void destroy()
        Called by the portlet container to indicate to a portlet that the portlet is being taken out of service. The default implementation does nothing.
        Specified by:
        destroy in interface Portlet