struts2 访问Web元素的4种方法

完整代码 ：Struts12AccessWebElement.rar

第一种也是最常用的一种方法实现这几个接口

RequestAware,SessionAware,ApplicationAware

struts以依赖注入方式把request，session和application赋上值，看一下完整的代码

package com.pengli.struts.parampack;

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.ActionSupport;

public class MyWinAction2 extends ActionSupport  implements RequestAware,SessionAware,ApplicationAware{

static int actionCount=0;
private Map<String, Object> my_Request;
private Map<String, Object> session;
private Map<String, Object> application;

public String add()
{
AddKey();
return "add";
}

@Override
public void setRequest(Map<String, Object> arg0) {
// TODO Auto-generated method stub
my_Request=arg0;
}

@Override
public void setApplication(Map<String, Object> arg0) {
// TODO Auto-generated method stub
application=arg0;
}

@Override
public void setSession(Map<String, Object> arg0) {
// TODO Auto-generated method stub
session = arg0;
}

private void AddKey()
{

++actionCount;
my_Request.put("a1", "Two"+actionCount);

++actionCount;
session.put("a2", "Two"+actionCount);

++actionCount;
application.put("a3", "Two"+actionCount);
}

}

第二种方式是实现ServletRequestAware接口

得到request接口后，再根据 request的方法去得到session和application

package com.pengli.struts.parampack;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.util.ServletContextAware;

import com.opensymphony.xwork2.ActionSupport;

public class MyWinAction3 extends ActionSupport implements ServletRequestAware {

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

public String add()    {
setAttribute();
return "add";
}

@Override
public void setServletRequest(HttpServletRequest arg0) {
// TODO Auto-generated method stub
request=arg0;
session=request.getSession();
application=session.getServletContext();

}

private void setAttribute()    {
request.setAttribute("a1", "ThreeA1");
session.setAttribute("a2", "ThreeA2");
application.setAttribute("a3", "ThreeA3");
}

}

第三种方式和第二种有点像，是用ServletActionContext得到request再得到sesion和application

package com.pengli.struts.parampack;

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 MyWinAction4 extends ActionSupport{

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

public String add(){

getInfo();
setAttribute();

return "add";
}

private void getInfo()
{
request = ServletActionContext.getRequest();
session = request.getSession();
application = session.getServletContext();
}

private void setAttribute()
{
request.setAttribute("a1", "FourA1");
session.setAttribute("a2", "FourA2");
application.setAttribute("a3", "FourA3");
}
}

最后一种方法是通过ActionContext得到相应的参数

package com.pengli.struts.parampack;

import java.util.Map;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

public class MyWiAction extends ActionSupport {

private UserModel user;
public  String add1()
{
if(user == null)
{
this.addFieldError("user", "user object is null");
return ERROR;
}
if(user.getName()== null||user.getAge() == null)
{
this.addFieldError("name", "name is null");
this.addFieldError("age", "age is null");
return ERROR;
}
System.out.println(user.getAge());
System.out.println(user.getName());
return "add1";
}
static int actionCount=0;
private Map request1;
private Map session1;
private Map application1;

public String add()
{
request1 = (Map)ActionContext.getContext().get("request");
session1=ActionContext.getContext().getSession();
application1 = ActionContext.getContext().getApplication();

AddKey();

return "add";
}

@Override
public String execute() throws Exception {
// TODO Auto-generated method stub

return super.execute();
}

public String add2()
{
return "add2";
}

public String add3()
{
return "add3";
}

private void AddKey()
{

++actionCount;
request1.put("a1", "a1haha"+actionCount);

++actionCount;
session1.put("a2", "a2haha"+actionCount);

++actionCount;
application1.put("a3", "a3haha"+actionCount);

}
public String edit()
{
return "edit";
}

public UserModel getUser() {
return user;
}

public void setUser(UserModel user) {
this.user = user;
}
}

再看一下web页面如何访问这些元素

<%@ page language="java" import="java.util.*" pageEncoding="GB18030"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@ taglib uri="/struts-tags" prefix="s" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

<title>My JSP 'Oneaddok.jsp' starting page</title>

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->

</head>

<body>
This is my JSP page. <br>
<s:property value="#request.a1" />|<%= request.getAttribute("a1") %> <br/>
<s:property value="#session.a2" />|<%= session.getAttribute("a2") %> <br/>
<s:property value="#application.a3" />|<%= application.getAttribute("a3") %> <br/>
</body>
</html>

再看一下struts.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
"http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>
<!-- Add packages here -->
<constant name="struts.devMode" value="true" />
<constant name="struts.enable.DynamicMethodInvocation" value="true"/>
<package name="default1" namespace="/" extends="struts-default">
<action name="One*1" class="com.pengli.struts.parampack.MyWiAction" method="{1}">
<result name ="{1}">
/Oneaddok.jsp
</result>
<result name="error">
/errorpage.jsp
</result>
</action>
<action name="One*2" class="com.pengli.struts.parampack.MyWinAction2" method="{1}">
<result name ="{1}">
/Oneaddok.jsp
</result>
<result name="error">
/errorpage.jsp
</result>
</action>
<action name="One*3" class="com.pengli.struts.parampack.MyWinAction3" method="{1}">
<result name ="{1}">
/Oneaddok.jsp
</result>
<result name="error">
/errorpage.jsp
</result>
</action>
<action name="One*4" class="com.pengli.struts.parampack.MyWinAction4" method="{1}">
<result name ="{1}">
/Oneaddok.jsp
</result>
<result name="error">
/errorpage.jsp
</result>
</action>
</package>
</struts>

完整代码 ：Struts12AccessWebElement.rar