Struts2取得Servlet API中的一些对象

Strutx 2.0你可以有两种方式获得这些对象：非IoC（控制反转Inversion of Control）方式和IoC方式。

非IoC方式

要获得上述对象，关键Struts 2.0中com.opensymphony.xwork2.ActionContext类。我们可以通过它的静态方法getContext()获取当前Action的上下文对象。 另外，org.apache.struts2.ServletActionContext作为辅助类（Helper Class），可以帮助您快捷地获得这几个对象。

HttpServletRequest request = ServletActionContext.getRequest();
HttpServletResponse response = ServletActionContext.getResponse();
HttpSession session = request.getSession();
如果你只是想访问session的属性（Attribute），你也可以通过ActionContext.getContext().getSession()获取或添加session范围（Scoped）的对象。

IoC方式

要使用IoC方式，我们首先要告诉IoC容器（Container）想取得某个对象的意愿，通过实现相应的接口做到这点。具体实现，请参考例6 IocServlet.java。
package tutorial;

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

import org.apache.struts2.ServletActionContext;

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

publicclass NonIoCServlet extends ActionSupport {
    private String message;
   
    public String getMessage() {
        return message;       
    }
   
    @Override
    public String execute() {   
        ActionContext.getContext().getSession().put("msg", "Hello World from Session!");
       
        HttpServletRequest request = ServletActionContext.getRequest();
        HttpServletResponse response = ServletActionContext.getResponse();       
        HttpSession session = request.getSession();
       
        StringBuffer sb =new StringBuffer("Message from request: ");
        sb.append(request.getParameter("msg"));
        sb.append("<br>Response Buffer Size: ");
        sb.append(response.getBufferSize());
        sb.append("<br>Session ID: ");
        sb.append(session.getId());
       
        message = sb.toString();
        return SUCCESS;
    }
}例6 classes/tutorial/NonIoCServlet.java

package tutorial;

import java.util.Map;

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

import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.interceptor.ServletResponseAware;
import org.apache.struts2.interceptor.SessionAware;

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

publicclass IoCServlet extends ActionSupport implements SessionAware, ServletRequestAware, ServletResponseAware {
    private String message;
    private Map att;
    private HttpServletRequest request;
    private HttpServletResponse response;   
   
    public String getMessage() {
        return message;       
    }
   
    publicvoid setSession(Map att) {
        this.att = att;
    }
   
    publicvoid setServletRequest(HttpServletRequest request) {
        this.request = request;
    }
   
    publicvoid setServletResponse(HttpServletResponse response) {
        this.response = response;
    }
   
    @Override
    public String execute() {       
        att.put("msg", "Hello World from Session!");
       
        HttpSession session = request.getSession();
       
        StringBuffer sb =new StringBuffer("Message from request: ");
        sb.append(request.getParameter("msg"));
        sb.append("<br>Response Buffer Size: ");
        sb.append(response.getBufferSize());
        sb.append("<br>Session ID: ");
        sb.append(session.getId());
       
        message = sb.toString();
        return SUCCESS;
    }
}


http://www.blogjava.net/max/archive/2006/10/18/75857.html
常用的Struts2.0的标志