struts2中如何得到request response 和session等对象

1 非IoC方式
要获得这几个对象，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。
ActionContext.getContext()code]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。

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;

public class 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();
  //      ActionContext.getContext().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;
    }
}

2 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。

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;
    }
}