portletdispatcherimpl.java

GridSphere 门户 提供一个基于 portlet 的高级开放源代码门户。GridSphere 是在欧盟提供基金的 GridLab 项目下开发的

/**
 * @author <a href="mailto:[e-mail]">Jason Novotny</a>
 * @version $Id: SportletDispatcher.java 4848 2006-06-10 18:06:15Z novotny $
 */
package org.gridsphere.portletcontainer.impl;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.gridsphere.layout.event.PortletWindowEvent;
import org.gridsphere.portlet.impl.SportletProperties;
import org.gridsphere.portletcontainer.DefaultPortletAction;
import org.gridsphere.portletcontainer.DefaultPortletRender;
import org.gridsphere.portletcontainer.PortletDispatcher;
import org.gridsphere.portletcontainer.PortletDispatcherException;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * The <code>PortletDispatcher</code> provides a mechanism for invoking portlet lifecycle methods by using a
 * <code>RequestDispatcher</code> from the Servlet API to forward requests to other portlets (servlets).
 *
 * @see <code>PortletInvoker</code>
 */
public class PortletDispatcherImpl implements PortletDispatcher {

    public static Log log = LogFactory.getLog(PortletDispatcherImpl.class);

    private RequestDispatcher rd;

    /**
     * Default constructor is kept private
     */
    private PortletDispatcherImpl() {
    }

    /**
     * Constructs a PortletDispatcher from a <code>RequestDispatcher</code> and an <code>ApplicationPortletConfig</code>
     *
     * @param rd the <code>RequestDispatcher</code>
     */
    public PortletDispatcherImpl(RequestDispatcher rd) {
        this.rd = rd;
    }

    public void init(HttpServletRequest req, HttpServletResponse res) throws PortletDispatcherException {
        req.setAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD, SportletProperties.INIT);
        try {
            include(req, res);
        } catch (ServletException e) {
            throw new PortletDispatcherException("Unable to initialize servlet", e.getRootCause());
        } catch (Exception e) {
            throw new PortletDispatcherException("Unable to initialize portlet: ", e);
        } finally {
            req.removeAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD);
        }
    }

    public void destroy(HttpServletRequest req, HttpServletResponse res) throws PortletDispatcherException {
        req.setAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD, SportletProperties.DESTROY);
        try {
            include(req, res);
        } catch (ServletException e) {
            throw new PortletDispatcherException("Unable to perform destroy", e.getRootCause());
        } catch (Exception e) {
            throw new PortletDispatcherException("Unable to perform destroy: ", e);
        } finally {
            req.removeAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD);
        }
    }

    public void service(DefaultPortletRender render, HttpServletRequest req, HttpServletResponse res) throws PortletDispatcherException {
        req.setAttribute(SportletProperties.RENDER_EVENT, render);
        req.setAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD, SportletProperties.SERVICE);
        try {
            include(req, res);
        } catch (ServletException e) {
            throw new PortletDispatcherException("Unable to perform service", e.getRootCause());
        } catch (Exception e) {
            throw new PortletDispatcherException("Unable to perform service", e);
        } finally {
            req.removeAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD);
        }
    }

    public void login(HttpServletRequest req, HttpServletResponse res) throws PortletDispatcherException {
        req.setAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD, SportletProperties.LOGIN);
        try {
            include(req, res);
        } catch (ServletException e) {
            throw new PortletDispatcherException("Unable to perform login", e.getRootCause());
        } catch (Exception e) {
            throw new PortletDispatcherException("Unable to perform login", e);
        } finally {
            req.removeAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD);
        }
    }

    public void logout(HttpServletRequest req, HttpServletResponse res) throws PortletDispatcherException {
        req.setAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD, SportletProperties.LOGOUT);
        try {
            include(req, res);
        } catch (ServletException e) {
            throw new PortletDispatcherException("Unable to perform logout", e.getRootCause());
        } catch (Exception e) {
            throw new PortletDispatcherException("Unable to perform logout", e);
        } finally {
            req.removeAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD);
        }
    }

    public void actionPerformed(DefaultPortletAction action, HttpServletRequest req, HttpServletResponse res) throws PortletDispatcherException {
        req.setAttribute(SportletProperties.ACTION_EVENT, action);
        req.setAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD, SportletProperties.SERVICE);
        req.setAttribute(SportletProperties.PORTLET_ACTION_METHOD, SportletProperties.ACTION_PERFORMED);
        try {
            include(req, res);
        } catch (ServletException e) {
            throw new PortletDispatcherException("Unable to perform actionPerformed", e.getRootCause());
        } catch (Exception e) {
            throw new PortletDispatcherException("Unable to perform actionPerformed", e);
        } finally {
            req.removeAttribute(SportletProperties.ACTION_EVENT);
            req.removeAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD);
            req.removeAttribute(SportletProperties.PORTLET_ACTION_METHOD);
        }
    }

    public void doTitle(HttpServletRequest req, HttpServletResponse res) throws PortletDispatcherException {
        req.setAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD, SportletProperties.SERVICE);
        req.setAttribute(SportletProperties.PORTLET_ACTION_METHOD, SportletProperties.DO_TITLE);
        try {
            include(req, res);
        } catch (ServletException e) {
            throw new PortletDispatcherException("Unable to perform doTitle", e.getRootCause());
        } catch (Exception e) {
            throw new PortletDispatcherException("Unable to perform doTitle", e);
        } finally {
            req.removeAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD);
            req.removeAttribute(SportletProperties.PORTLET_ACTION_METHOD);
        }
    }


    public void windowEvent(PortletWindowEvent event, HttpServletRequest req, HttpServletResponse res) throws PortletDispatcherException {
        req.setAttribute(SportletProperties.WINDOW_EVENT, event);
        req.setAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD, SportletProperties.SERVICE);
        req.setAttribute(SportletProperties.PORTLET_ACTION_METHOD, SportletProperties.WINDOW_EVENT);
        try {
            include(req, res);
        } catch (ServletException e) {
            throw new PortletDispatcherException("Unable to perform windowEvent", e.getRootCause());
        } catch (Exception e) {
            throw new PortletDispatcherException("Unable to perform windowEvent", e);
        } finally {
            req.removeAttribute(SportletProperties.WINDOW_EVENT);
            req.removeAttribute(SportletProperties.PORTLET_LIFECYCLE_METHOD);
            req.removeAttribute(SportletProperties.PORTLET_ACTION_METHOD);
        }
    }

    /**
     * Underlying method used by all other dispatcher methods to invoke the appropriate portlet lifecycle method
     *
     * @param req a <code>HttpServletRequest</code>
     * @param res a <code>HttpServletResponse</code>
     * @throws IOException      if an I/O error occurs
     * @throws ServletException if a servlet exception occurs
     */
    protected synchronized void include(HttpServletRequest req, HttpServletResponse res) throws IOException, ServletException {
        rd.include(req, res);
    }

}