看程式碼前要先了解這些知識：

Servlet ServletContextEvent事件

下面是JS框架實現程式碼：

public class RuleEngineListener implements ServletContextListener {
	private static Logger logger = Logger.getLogger(RuleEngineListener.class);

	/**
	 * 當Servlet 容器終止Web 應用時呼叫該方法。在呼叫該方法之前，容器會先銷燬所有的Servlet 和Filter 過濾器。
	 */
	public void contextDestroyed(ServletContextEvent arg0) {

	}

	/**
	 * 容器初始化時啟動一個新執行緒載入所有的業務規則並生成JS檔案.
	 */
	public void contextInitialized(ServletContextEvent arg0) {
		if (logger.isDebugEnabled()) {
			logger.debug("RuleEngineListener context Initialize start.");
		}

		WebApplicationContext rwp = WebApplicationContextUtils
				.getRequiredWebApplicationContext(arg0.getServletContext());
		ILoadRuleService loadRuleService = (ILoadRuleService) rwp
				.getBean("nssb_gzyq_loadRuleService");

		ICreateJsFileService createJsFileService = (ICreateJsFileService) rwp
				.getBean("nssb_gzyq_createJsFileService");

		IRuleInfoDao ruleInfoDao = (IRuleInfoDao) rwp
				.getBean("nssb_gzyq_ruleInfoDao");

		// 啟動一個新執行緒執行相應的業務邏輯
		new Thread(new CreateRuleJsService(loadRuleService,
				createJsFileService, ruleInfoDao)).start();

		if (logger.isDebugEnabled()) {
			logger.debug("RuleEngineListener context Initialize end.");
		}
	}

}
 

需要配置xml：

<listener>
   <listener-class>com.ycjf.ycs.util.genrulejs.RuleEngineListener</listener-class>
</listener>