在Action操作中，关键就是Action中的exectue方法，但是此方法并没有request、session、application等对象作为参数，自然就不能利用这些对象来操作。
通常可以使用四种方式来获取这些对象：
方式一、与Servlet解耦合的非IOC方式
获取的scope对象与容器无关，通过ActionContext获取。
package test002;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import java.util.Map;
/**
* Created by yangcs on 2017/1/19.
* 通过与servlet解耦和的非IOC方式来获取scope对象
*/
public class ScopeAction extends ActionSupport{
private String name;
private String req;
private String sess;
public String getReq() {
return req;
}
public void setReq(String req) {
this.req = req;
}
public String getSess() {
return sess;
}
public void setSess(String sess) {
this.sess = sess;
}
public String getApp() {
return app;
}
public void setApp(String app) {
this.app = app;
}
private String app;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
ActionContext context; //这个是解耦和的关键
Map request;
Map session;
Map application;
@Override
public String execute(){
context = ActionContext.getContext();
request = (Map) context.get("request");
session =context.getSession();
application = context.getApplication();
request.put("req",req);
session.put("sess",sess);
application.put("app",app);
return SUCCESS;
}
}
分析：通过ActionContext的getContext静态方法得到ActionContext对象，然后ActionContext
对象调用get方法来获取一个存储在request范围中的对象。我们使用el或通过request.getAttribute
这样的方式均可以获取对象值，这说明了这些Map request对象实际是存储在request范围内的对象。
方式二、与Servlet解耦合的IOC方式
package test002;
import com.opensymphony.xwork2.ActionSupport;
import org.apache.struts2.interceptor.ApplicationAware;
import org.apache.struts2.interceptor.RequestAware;
import org.apache.struts2.interceptor.SessionAware;
import java.util.Map;
/**
* Created by yangcs on 2017/1/19.
* 与servlet解耦和的IOC方式（依赖于struts框架来实现对象的实例化，依赖注入、控制反转）获取scope对象
*/
public class ScopeAction02 extends ActionSupport implements RequestAware,SessionAware,ApplicationAware{
private Map request;
private Map session;
private Map application;
@Override
public void setApplication(Map<String, Object> map) {
application = map;
}
@Override
public void setRequest(Map<String, Object> map) {
request = map;
}
@Override
public void setSession(Map<String, Object> map) {
session = map;
}
private String req;
private String sess;
private String app;
public String getReq() {
return req;
}
public void setReq(String req) {
this.req = req;
}
public String getSess() {
return sess;
}
public void setSess(String sess) {
this.sess = sess;
}
public String getApp() {
return app;
}
public void setApp(String app) {
this.app = app;
}
@Override
public String execute(){
request.put("req",req);
session.put("sess",sess);
application.put("app",app);
System.out.println("reqMap为："+request);
return "success";
}
}
说明：此方法其实和方式一很相似，只是在方式一中我们需要手动的为Map request赋值，
但是在方式二中它是通过实现接口，在重写接口中的方法中完成对Map requset的赋值，所以称之IOC方式。
强调：方式二是开发中主要用的方式，应重点掌握
方式三、与Servlet耦合的非IOC方式
package test002;
import com.opensymphony.xwork2.ActionSupport;
import org.apache.struts2.ServletActionContext;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
/**
* Created by yangcs on 2017/1/19.
* 与servlet相耦合的非IOC方式获取scope对象
* 这种方式获取的为纯粹的Scope对象，它与容器相关，这些Scope对象操作性更强
*/
public class ScopeAction03 extends ActionSupport{
private String req;
private String sess;
private String app;
public String getReq() {
return req;
}
public void setReq(String req) {
this.req = req;
}
public String getSess() {
return sess;
}
public void setSess(String sess) {
this.sess = sess;
}
public String getApp() {
return app;
}
public void setApp(String app) {
this.app = app;
}
HttpServletRequest request;
HttpSession session;
ServletContext application;
@Override
public String execute(){
request = ServletActionContext.getRequest(); //这里，就是耦合了servlet了
session = request.getSession();
application = ServletActionContext.getServletContext();
request.setAttribute("req",req);
session.setAttribute("sess",sess);
application.setAttribute("app",app);
return SUCCESS;
}
}
此方法获取的纯粹的Scope对象，它与容器相关，这些Scope对象可操作性更强。
方式四、与Servlet耦合的IOC方式
package test002;
import com.opensymphony.xwork2.ActionSupport;
import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.util.ServletContextAware;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
/**
* Created by yangcs on 2017/1/19.
* 与servlet耦合的情况下使用IOC获取scope对象
*/
public class ScopeAction04 extends ActionSupport implements ServletRequestAware,ServletContextAware{
HttpServletRequest request;
HttpSession session;
ServletContext application;
@Override
public void setServletRequest(HttpServletRequest httpServletRequest) {
request = httpServletRequest;
}
@Override
public void setServletContext(ServletContext servletContext) {
application = servletContext;
}
private String req;
private String sess;
private String app;
public String getReq() {
return req;
}
public void setReq(String req) {
this.req = req;
}
public String getSess() {
return sess;
}
public void setSess(String sess) {
this.sess = sess;
}
public String getApp() {
return app;
}
public void setApp(String app) {
this.app = app;
}
@Override
public String execute(){
request.setAttribute("req",req);
session = request.getSession();
session.setAttribute("sess",sess);
application.setAttribute("app",app);
return SUCCESS;
}
}
附：用于测试的访问页面及结果展示页面：
struts.xml配置文件：
<?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>
<package name="test002" namespace="/" extends="struts-default">
<action name="Action003" class="test002.ScopeAction">
<result name="success">/JSP/scope01.jsp</result>
</action>
<action name="Action004" class="test002.ScopeAction02">
<result name="success">/JSP/scope01.jsp</result>
</action>
<action name="Action005" class="test002.ScopeAction03">
<result name="success">/JSP/scope01.jsp</result>
</action>
<action name="Action006" class="test002.ScopeAction04">
<result name="success">/JSP/scope01.jsp</result>
</action>
</package>
</struts>
输入参数页面：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>scope</title>
</head>
<body>
本页面展示在action中获取scope对象<br><br>
<form method="get" action="Action003.action">
这个表单是使用与servlet解耦和的非IOC方式来获取scope对象<br>
request:<input type="text" name="req"/><br>
session:<input type="text" name="sess"/><br>
appliaction:<input type="text" name="app"/><br>
<input type="submit"/>
</form>
<form method="get" action="Action004.action">
这个表单是使用与servlet解耦和的IOC方式来获取scope对象(主要使用)<br>
request:<input type="text" name="req"/><br>
session:<input type="text" name="sess"/><br>
appliaction:<input type="text" name="app"/><br>
<input type="submit"/>
</form>
<form method="get" action="Action005.action">
这个表单是使用与servlet耦和的非IOC方式来获取scope对象<br>
request:<input type="text" name="req"/><br>
session:<input type="text" name="sess"/><br>
appliaction:<input type="text" name="app"/><br>
<input type="submit"/>
</form>
<form method="get" action="Action006.action">
这个表单是使用与servlet耦和的IOC方式来获取scope对象<br>
request:<input type="text" name="req"/><br>
session:<input type="text" name="sess"/><br>
appliaction:<input type="text" name="app"/><br>
<input type="submit"/>
</form>
</body>
</html>
获取参数展示页面：
<%--
Created by IntelliJ IDEA.
User: yangcs
Date: 2017/1/19
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>scope01</title>
</head>
<body>
request:${requestScope.req}<br>
session:${sessionScope.sess}<br>
application:${applicationScope.app}<br>
</body>
</html>
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