核心思想
1、ActionContext
HttpServletRequest getAttribute setAttribute
ActionContext get put
//ActionContext.getContext() 获取入口
ActionContext.getContext().put("key", "value");
2、ServletRequestAware
package com.test.action; public class LoginAction extends ActionSupport implements ServletRequestAware { private static final long serialVersionUID = -74906200993380354L; private HttpServletRequest request; @SuppressWarnings("unchecked") public String execute() throws Exception { if("james".equals(this.getUsername()) && "james".equals(this.getPassword())){ Map map = ActionContext.getContext().getSession(); //ActionContext.getContext() 获取入口 //ActionContext.getContext().put("james", "get from AcionContext"); request.setAttribute("chenkai", "from ServletRequestAware"); map.put("user", "james"); return "success"; }else { this.addFieldError("username", "username or password is wrong"); return "failer"; } } /* * 实现 ServletRequestAware 接口 方法 * struts2 自动加载，【ioc 依赖注入的方式】 将与容器相关的request参数set到应用里 */ public void setServletRequest(HttpServletRequest request) { this.request = request; } }
3、ServletResponseAware 与 Cookie 的使用
public class LoginAction extends ActionSupport implements ServletResponseAware { private HttpServletResponse response; public String execute() throws Exception { Cookie cookie = new Cookie("name", "james"); cookie.setMaxAge(100); response.addCookie(cookie); return SUCCESS; } }
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> </head> <body> username:${requestScope.username }<br> password:${requestScope.password }<br> Cookie:${cookie.name } </body> </html>
4、ServletActionContext
public String execute() throws Exception { HttpServletResponse response = ServletActionContext.getResponse(); Cookie cookie = new Cookie("name", "james"); cookie.setMaxAge(100); response.addCookie(cookie); return SUCCESS; }
建议使用顺序
a) ActionContext 【首选】
b) ServletActionContext [如果需要使用reponse]
c) ServletRequestAware [必须实现接口]