Action中获得request，session的四种方式

2012-11-16

Action中取得request，session的四种方式!DOCTYPE struts PUBLIC??? -//Apache Software Foundation//DTD

Action中取得request，session的四种方式
<!DOCTYPE struts PUBLIC
??? "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
??? "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
??????? <action name="login" >result.jsp</result>
??????? </action>
???????
??????? <action name="login2" >result.jsp</result>
??????? </action>
???????
??????? <action name="login3" >result.jsp</result>
??????? </action>
???????
??????? <action name="login4" >result.jsp</result>
??????? </action>
??? </package>
???
</struts>

其中的LoginAction，Login2Action，Login3Action，Login4Action分别对应四种方式的Action。

文件名：result.jsp
文件内容：
<%@ page contentType="text/html; charset=gb2312" %>
<%@ taglib uri="/struts-tags" prefix="s"%>

<html>
request 属性是 ${requestScope.attribute} 
session 属性是 ${sessionScope.attribute} 
application 属性是 ${applicationScope.attribute} 
</html>

文件名：getrequest.jsp
文件内容：
<%@ page contentType="text/html; charset=gb2312" %>
<%@ taglib uri="/struts-tags" prefix="s"%>
<html>
<a href="login.action">servlet 不相关的非IoC 取得Request等对象的方式</a> 
<a href="login2.action">servlet 不相关的 IoC 取得Request等对象的方式</a> 
<a href="login3.action">servlet 相关的非IoC 取得Request等对象的方式</a> 
<a href="login4.action">servlet 相关的 IoC 取得Request等对象的方式</a> 
</form>
</html>

然后分别叙述4种方式，
1，servlet 不相关的非IoC 取得Request等对象的方式
这种方法先取得ActionContext，然后获取Map类型的request等对象

Action文件：
package struts2.login;

import java.util.Map;

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

public class LoginAction? extends ActionSupport{
??? private ActionContext context;
??? private Map request;
??? private Map session;
??? private Map application;
???
??? @Override
??? public String execute() throws Exception {
??? ??? // TODO Auto-generated method stub
??? ??? this.context = ActionContext.getContext();
??? ??? this.request = (Map)this.context.get("request");
??? ??? this.session = this.context.getSession();
??? ??? this.application = this.context.getApplication();
??? ??? this.request.put("attribute", "request value servlet 不相关的非IoC ");
??? ??? this.session.put("attribute", "session value servlet 不相关的非IoC ");
??? ??? this.application.put("attribute", "application value servlet 不相关的非IoC ");
??? ??? return SUCCESS;
??? }
}

2，servlet 不相关的 IoC 取得Request等对象的方式
这种方法，是实现特定的接口，由container来设定request等对象。请注意如下代码示例中红色文字的部分。

Action文件：
package struts2.login;

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 Login2Action? extends ActionSupport
??? implements RequestAware , SessionAware, ApplicationAware{
??? private Map request;
??? private Map session;
??? private Map application;
???
??? @Override
??? public String execute() throws Exception {
??? ??? // TODO Auto-generated method stub
??? ??? this.request.put("attribute", "request value servlet 不相关的 IoC ");
??? ??? this.session.put("attribute", "session value servlet 不相关的 IoC ");
??? ??? this.application.put("attribute", "application value servlet 不相关的 IoC ");
??? ??? return SUCCESS;
??? }

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

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

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

3，servlet 相关的非IoC 取得Request等对象的方式
这种方法可以获取servlet相关的request等对象，也就是说这种方式取出的request对象不单单是设定属性的作用，而是可以获取http相关的信息。
取出方法，请参看代码中的蓝字部分。

Action文件：
package struts2.login;

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 Login3Action? extends ActionSupport{
??? private HttpServletRequest request;
??? private HttpSession session;
??? private ServletContext application;
???
??? @Override
??? public String execute() throws Exception {
??? ??? // TODO Auto-generated method stub
??? ??? this.request = ServletActionContext.getRequest();
??? ??? this.session = this.request.getSession();
??? ??? this.application = ServletActionContext.getServletContext();
??? ??? this.request.setAttribute("attribute", "request value servlet 相关的非IoC ");
??? ??? this.session.setAttribute("attribute", "session value servlet 相关的非IoC ");
??? ??? this.application.setAttribute("attribute", "application value servlet 相关的非IoC ");
??? ??? return SUCCESS;
??? }
???
}

4，servlet 相关的 IoC 取得Request等对象的方式

这种方法也可以获取servlet相关的request等对象，也就是说这种方式取出的request对象不单单是设定属性的作用，而是可以获取http相关的信息。
但是取出方法是通过接口进行实现，也就是由struts2的container来设定，请参看代码中的红字部分。

Action文件：
package struts2.login;

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 Login4Action? extends ActionSupport
??? implements ServletRequestAware , ServletContextAware{
??? private HttpServletRequest request;
??? private HttpSession session;
??? private ServletContext application;
???
??? @Override
??? public String execute() throws Exception {
??? ??? // TODO Auto-generated method stub
??? ??? this.request.setAttribute("attribute", "request value servlet 相关的 IoC ");
??? ??? this.session = this.request.getSession();
??? ??? this.session.setAttribute("attribute", "session value servlet 相关的 IoC ");
??? ??? this.application.setAttribute("attribute", "application value servlet 相关的 IoC ");
??? ??? return SUCCESS;
??? }

??? @Override
??? public void setServletRequest(HttpServletRequest arg0) {
??? ??? // TODO Auto-generated method stub
??? ??? this.request = arg0;
??? }

??? @Override
??? public void setServletContext(ServletContext arg0) {
??? ??? // TODO Auto-generated method stub
??? ??? this.application = arg0;
??? }
}

好，把执行结果的图上来一看，一目了然，不知道你对action中取request等对象的这几种方式，了解了多少呢？

Action中获得request，session的四种方式

转自：http://www.cnblogs.com/lxJack/archive/2011/04/03/2004782.html

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Action中获得request，session的四种方式