struts2访问或添加几个属性（request/session/application属性）

https://blog.csdn.net/hebiao100/article/details/7385055

struts2添加request、session、application属性

第一种方法：

ActionContext ctx = ActionContext.getContext();
    ctx.put("r1", list);//向request中添加属性
    ctx.getSession().put("s1",list);//向session中添加属性
    ctx.getApplication().put("a1", list);//向application中添加属性  

ctx.put("names", Arrays.asList("小航，小王，小韩"));//向request中添加属性

HttpSession session =null;
        session = ServletActionContext.getRequest().getSession();
        if(session.getAttribute("user") != null) {
            session.removeAttribute("user");
        }
        session.setAttribute("user", user);
Map<String,Object> session = null;
        session = ActionContext.getContext().getSession();
        if(session.containsKey("user")){
            session.remove("user");
        }  

        session.put("user", user); 

第二种方法：

使用 ServletRequestAware接口

public class LoginAction4 extends ActionSupport implements ServletRequestAware {  

    private HttpServletRequest request;
    private HttpSession session;
    private ServletContext application;  

    public String execute() {
        request.setAttribute("r1", "r1");
        session.setAttribute("s1", "s1");
        application.setAttribute("a1", "a1");
        return SUCCESS;
    }  

    @Override
    public void setServletRequest(HttpServletRequest request) {
        this.request = request;
        this.session = request.getSession();
        this.application = session.getServletContext();
    }  

}  

struts2访问request、session、application属性

第一种方法：

使用struts tag：

<s:property value="#request.r1"/>
<s:property value="#session.s1"/>
<s:property value="#application.a1"/>   

第二种方法：

使用jsp对象

<%=request.getAttribute("r1") %> <br />
<%=session.getAttribute("s1") %> <br />
<%=application.getAttribute("a1")%> <br />  

<c:forEach items="${names}" var="name">
   ${name}

</c:forEach>