Simple way to do configuration for a web app.

SimpleContextListenerConfig.java

package com.evocatus.util;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;


public class SimpleContextListenerConfig /*extend ResourceBundle */ implements ServletContextListener{
		
	private ServletContext servletContext;

    @Override
	public void contextInitialized(ServletContextEvent sce) {
		servletContext = sce.getServletContext();
		servletContext.setAttribute(getClass().getCanonicalName(), this);
	}

	@Override
	public void contextDestroyed(ServletContextEvent sce) {

	}
	
	public static String getProperty(ServletContext sc, String propName, String defaultValue) {
		SimpleContextListenerConfig config = getConfig(sc);
		return config.getProperty(propName, defaultValue);
	}

	public static SimpleContextListenerConfig getConfig(ServletContext sc) {
		SimpleContextListenerConfig config = 
			(SimpleContextListenerConfig) sc.getAttribute(SimpleContextListenerConfig.class.getCanonicalName());
		return config;
	}

	public String getProperty(String propName, String defaultValue)
    {
		/*
		 * TODO cache properties
		 */
        String property = null; 
        
        if (property == null)
            property = servletContext.getInitParameter(propName);
        if (property == null)
        	System.getProperty(propName, null);
        //TODO Get From resource bundle
        if (property == null)
            property = defaultValue;

        return property;
    }
}