对struts2中OGNL数据处理的一点理解

  在MVC模式的view层中，jsp中的form表单中元素如input等，都使用OGNL的表达式作为name的值。而在form提交时，这些值都会被设置到Action中的java对象中。而当Action转向到JSP时，struts2的Tag又可以从Action的java对象中，通过OGNL进行取值。
 

<form method="post" action="/struts-example/ognl.action">   
    user name: <input type="text" name="user.name" value="downpour" />   
    department name: <input type="text" name="department.name" value="dev" />   
    <input type="submit" value="submit" />   
</form>  

public class OgnlAction extends ActionSupport {   
  
    private static final Log logger = LogFactory.getLog(OgnlAction.class);   
  
    private User user;   
       
    private Department department;   
       
    /* (non-Javadoc)  
     * @see com.opensymphony.xwork2.ActionSupport#execute()  
     */  
    @Override  
    public String execute() throws Exception {   
        logger.info("user name:" + user.getName());   // -> downpour   
        logger.info("department name:" + department.getName());   // -> dev   
        return super.execute();   
    }   
  
    // setter and getters   
}   

  
user name: <s:property value="user.name" />   
department name: <s:property value="department.name" />