2. 在系统启动的时候，把所有的资源load到内存作为缓存
由于资源信息对于每个项目来说，相对固定，所以我们可以将他们在系统启动的时候就load到内存作为缓存。这里做法很多，我给出的示例是将资源的存放在servletContext中。
Java代码
public class ServletContextLoaderListener implements ServletContextListener {
/* (non-Javadoc)
* @see javax.servlet.ServletContextListener#contextInitialized(javax.servlet.ServletContextEvent)
*/
public void contextInitialized(ServletContextEvent servletContextEvent) {
ServletContext servletContext = servletContextEvent.getServletContext();
SecurityManager securityManager = this.getSecurityManager(servletContext);
Map<String, String> urlAuthorities = securityManager.loadUrlAuthorities();
servletContext.setAttribute("urlAuthorities", urlAuthorities);
}
/* (non-Javadoc)
* @see javax.servlet.ServletContextListener#contextDestroyed(javax.servlet.ServletContextEvent)
*/
public void contextDestroyed(ServletContextEvent servletContextEvent) {
servletContextEvent.getServletContext().removeAttribute("urlAuthorities");
}
/**
* Get SecurityManager from ApplicationContext
*
* @param servletContext
* @return
*/
protected SecurityManager getSecurityManager(ServletContext servletContext) {
return (SecurityManager) WebApplicationContextUtils.getWebApplicationContext(servletContext).getBean("securityManager");
}
}
public class ServletContextLoaderListener implements ServletContextListener {
/* (non-Javadoc)
* @see javax.servlet.ServletContextListener#contextInitialized(javax.servlet.ServletContextEvent)
*/
public void contextInitialized(ServletContextEvent servletContextEvent) {
ServletContext servletContext = servletContextEvent.getServletContext();
SecurityManager securityManager = this.getSecurityManager(servletContext);
Map<String, String> urlAuthorities = securityManager.loadUrlAuthorities();
servletContext.setAttribute("urlAuthorities", urlAuthorities);
}
/* (non-Javadoc)
* @see javax.servlet.ServletContextListener#contextDestroyed(javax.servlet.ServletContextEvent)
*/
public void contextDestroyed(ServletContextEvent servletContextEvent) {
servletContextEvent.getServletContext().removeAttribute("urlAuthorities");
}
/**
* Get SecurityManager from ApplicationContext
*
* @param servletContext
* @return
*/
protected SecurityManager getSecurityManager(ServletContext servletContext) {
return (SecurityManager) WebApplicationContextUtils.getWebApplicationContext(servletContext).getBean("securityManager");
}
}