## 往ValueStack的root區存數據 ### action屬性方式 ~~~ public class HelloAction extends ActionSupport { private String username; public String getUsername() { return username; } public String index() { //往值棧的root區存數據 username = "jack"; //從值棧中獲取數據 ValueStack valueStack = ActionContext.getContext().getValueStack(); String username = valueStack.findString("username"); System.out.println(username); return SUCCESS; } } ~~~ 頁面:root區獲取 數據不需要加#號,context區需要加#號. ~~~ <s:property value="username"></s:property> //類似調用valueStack.find('username') ~~~  ### ValueStack的API方式 ~~~ public class HelloAction extends ActionSupport { public String index() { User user = new User(); user.setName("jack"); user.setAge(20); //獲取root區 ValueStack valueStack = ActionContext.getContext().getValueStack(); CompoundRoot root = valueStack.getRoot(); //往root區存放數據 root.push(user); return SUCCESS; } } ~~~ 頁面: ~~~ <s:property value="name"></s:property> <s:property value="age"></s:property> ~~~ ## 注意 不止當前訪問的action在root區,如果當前action實現modelDriver接口,modelDriver接口里面封裝的對象也在root區域.