struts2 action取得request,session,appilcation的方法。

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Map类型——request,session,application

真实类型——HttpServletRequest,HttpSession,ServletContext

Map类型是Struts对真实类型的一个封装，会将真实类型映射到Map类型中

取得上述元素有以下4种方法

1 通过ActionContext来访问request,session,application对象

2 通过实现RequestAware、SessionAware、ApplicationAware

接口来访问request,session,application对象(常用)

3 通过ServletActionContext来访问request,session,application对象

4 通过实现ServletRequestAware接口来访问request,session,application对象

第一种方法

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;
}
}
通过取得Struts的Action的上下文来取得上述三种元素，map类型的。

方法二

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;

// IOC

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;
}
}

通过Struts注入进来三个元素，map类型。

前台jsp页面获取后台值的方式

<s:property value=”#request.r1> | <%=request.getAttribute(“r1″)%>
<s:property value=”#session.s1″/> | <%=session.getAttribute(“s1″)%>
<s:property value=”#application.a1″/> |<%=application.getAttribute(“a1″)%>

方法三

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;
}
}

取得的是真实的类型

方法四
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();
}
}

http://blog.csdn.net/randomnet/article/details/8629974