后台action不能通过request等获取前台数据, 如果有人登陆了, 会往session设定值, 怎么实现呢?
action如何往session里设定值?
所以action访问 request, session,application等web元素的方法?
总结:
1. jsp调用action
2. action里 用map的IoC方法给session赋值
public class LoginAction2 extends ActionSupport implements RequestAware,SessionAware, ApplicationAware
session.put("s1", "name");
3. 在jsp显示里用 <s:property value="#request.变量名"/> 调用变量
也可以通过 <s:property value="#parameters.name"/>
只介绍一种最常用的:
1. jsp页面显示: 4个按钮分别提交同一个form的方法:
<form name="f" action="" method="post"> 用户名:<input type="text" name="name"/> 密码:<input type="text" name="password"/> <br /> <input type="button" value="submit1" onclick="javascript:document.f.action='login/login1';document.f.submit();" /> <input type="button" value="submit2" onclick="javascript:document.f.action='login/login2';document.f.submit();" /> <input type="button" value="submit3" onclick="javascript:document.f.action='login/login3';document.f.submit();" /> <input type="button" value="submit4" onclick="javascript:document.f.action='login/login4';document.f.submit();" /> </form>
2. struts.xml配置:
<package name="login" extends="struts-default" namespace="/login"> <action name="login*" class="com.bjsxt.struts2.user.action.LoginAction{1}"> <result>/user_login_success.jsp</result> </action> </package>
3. action 的4种处理方法:
loginAction1.java: 取得Map类型的方法
package com.bjsxt.struts2.user.action; import java.util.Map; import com.opensymphony.xwork2.ActionContext; import com.opensymphony.xwork2.ActionSupport; public class LoginAction1 extends ActionSupport { private Map request; private Map session; private Map application; public LoginAction1() { request = (Map)ActionContext.getContext().get("request"); session = ActionContext.getContext().getSession(); application = ActionContext.getContext().getApplication(); } public String execute() { request.put("r1", "r1"); session.put("s1", "s1"); application.put("a1", "a1"); return SUCCESS; } }
loginAction2.java: 取得Map类型的 IoC方法: 最常用
package com.bjsxt.struts2.user.action; import java.util.Map; import org.apache.struts2.interceptor.ApplicationAware; import org.apache.struts2.interceptor.RequestAware; import org.apache.struts2.interceptor.SessionAware; import com.opensymphony.xwork2.ActionContext; import com.opensymphony.xwork2.ActionSupport; public class LoginAction2 extends ActionSupport implements RequestAware,SessionAware, ApplicationAware { private Map<String, Object> request; private Map<String, Object> session; private Map<String, Object> application; //DI dependency injection //IoC inverse of control public String execute() { request.put("r1", "r1"); session.put("s1", "s1"); application.put("a1", "a1"); return SUCCESS; } @Override public void setRequest(Map<String, Object> request) { this.request = request; } @Override public void setSession(Map<String, Object> session) { this.session = session; } @Override public void setApplication(Map<String, Object> application) { this.application = application; } }
loginAction3.java: 取得真实类型的 方法:
package com.bjsxt.struts2.user.action; import javax.servlet.ServletContext; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpSession; import org.apache.struts2.ServletActionContext; import com.opensymphony.xwork2.ActionSupport; public class LoginAction3 extends ActionSupport { private HttpServletRequest request; private HttpSession session; private ServletContext application; public LoginAction3() { request = ServletActionContext.getRequest(); session = request.getSession(); application = session.getServletContext(); } public String execute() { request.setAttribute("r1", "r1"); session.setAttribute("s1", "s1"); application.setAttribute("a1", "a1"); return SUCCESS; } }
loginAction4.java: 取得真实类型的 IoC 方法:
package com.bjsxt.struts2.user.action; import javax.servlet.ServletContext; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpSession; import org.apache.struts2.interceptor.ServletRequestAware; import com.opensymphony.xwork2.ActionSupport; 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(); } }
最后如何在jsp中拿到request等值: <s:property value="#request.变量名"/>
#代表提取的不是 valuestack里的内容,而是context里的值
<body> User Login Success! <br /> <s:property value="#request.r1"/> | <%=request.getAttribute("r1") %> <br /> <s:property value="#session.s1"/> | <%=session.getAttribute("s1") %> <br /> <s:property value="#application.a1"/> | <%=application.getAttribute("a1") %> <br /> <s:property value="#parameters.name"/> <br /> <s:property value="#parameters.password"/> <br /> <s:property value="#attr.a1"/><br /> <s:property value="#attr.s1"/><br /> <s:property value="#attr.r1"/><br /> <s:debug></s:debug> <br /> </body>