package com.sc2Blog.web;
import javax.servlet.*;
import com.sc2Blog.model.Database;

/**
 * This listener creates a database connection when a servlet starts and
 * stores the database connection as a attribute so all classes in the webapp
 * can access the database easily. When the servlets terminate the listener
 * closes the db connection.
 * @author andber06
 * @version 2.0 2010-04-13
 */


public  class BlogServletContextListener implements ServletContextListener {


    //private ServletContext context = null;
    private Database mDatabase;

    /**
     * This method is called when the webapp starts. It creates a database
     * object and connects to the database. Then stores the database connection
     * as a attribute.
     * @param event - the event we are listening for
     *
     */
    public void contextInitialized(ServletContextEvent event)
    {
        // Create a context object
        ServletContext context = event.getServletContext();

        // The database info from the web.xml file
        String dbDriver = event.getServletContext().getInitParameter("dbDriver");
        String dbUrl = event.getServletContext().getInitParameter("dbUrl");
        String dbUser = event.getServletContext().getInitParameter("dbUsername");
        String dbPassword = event.getServletContext().getInitParameter("dbPassword");

        // Create a database object
        mDatabase = new Database();
        // Connect to the database
        mDatabase.connect( dbDriver, dbUrl,dbUser, dbPassword);
        // Store the connected database in the context as a attribute
        context.setAttribute("database", mDatabase);

        //  this.context = event.getServletContext();
    }

   /**
    * This method is called when the webapp ends. It closes the database
    * connection.
    * @param event - the event we are listening for
    *
    */
   public void contextDestroyed(ServletContextEvent event)
   {
      // Close the connection
      mDatabase.closeConnection();
   }

}