spring几种获取 HttpServletRequest 对象的方式

以下的 request 实例都编号了，一共 4 种 方式

1.@Autowired 方式
2.public void Test(HttpServletRequest request1, HttpServletResponse resp,HttpSession session1) 方式
3.((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest(); 方式
4.Global.getHttpServletRequest(); 方式，该方式基于 第三种做的封装


方法4 最灵活，不需要每个 action 中都定义 HttpServletRequest 参数。


LoginController.java

@Controller  
@RequestMapping("/demo")  
public class LoginController{  
    @Autowired  
    private  HttpServletRequest request2;  
  
  
  
  
    @RequestMapping("test")  
    @ResponseBody  
    public void Test(HttpServletRequest request1, HttpServletResponse resp,HttpSession session1){  
        resp.setCharacterEncoding("UTF=8");  
        resp.setContentType("text/html;charset=UTF-8");  
            
        String key = "test_date";  
        HttpSession session = request1.getSession();  
        session.setAttribute(key, new Date());  
        String sessionId = session.getId();  
        Date time = (Date)session.getAttribute(key);  
  
  
        HttpServletRequest request3 = ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest();  
        HttpServletRequest request4 = Global.getHttpServletRequest();  
          
        //判断session是不是新创建的  
        try {  
            if (session.isNew()) {  
                    resp.getWriter().print(java.text.MessageFormat.format(  
                            "【{0}】session创建成功，session的id是：</br>{1}</br>{2}</br>{3}</br>{4}</br>{5}"  
                            , StringExtend.getString(time)  
                            , sessionId  
                            , session1.getId()  
                            , request2.getSession().getId()  
                            , request3.getSession().getId()  
                            , request4.getSession().getId()));  
                  
            }else {  
                resp.getWriter().print(java.text.MessageFormat.format(  
                        "【{0}】服务器已经存在该session了，session的id是：</br>{1}</br>{2}</br>{3}</br>{4}</br>{5}"  
                            , StringExtend.getString(time)  
                            , sessionId  
                            , session1.getId()  
                            , request2.getSession().getId()  
                            , request3.getSession().getId()  
                            , request4.getSession().getId()));  
            }  
        } catch (IOException e) {  
                // TODO Auto-generated catch block  
                e.printStackTrace();  
        }  
    }  

Global.java

import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpSession;  
  
  
import org.springframework.web.context.request.RequestContextHolder;  
import org.springframework.web.context.request.ServletRequestAttributes;  
  
  
  
  
/**  
* 使用该类必须在 web.xml 中添加监听（org.springframework.web.context.request.RequestContextListener） 
* 该作用域仅适用于WebApplicationContext环境 
*/  
public class Global {  
    static String _loginSessionKey="login_session";  
    /** 
     * 获取当前请求session 
     * @return 
     */  
    public static HttpServletRequest getHttpServletRequest(){  
        HttpServletRequest request = ((ServletRequestAttributes)RequestContextHolder  
                .getRequestAttributes())  
                .getRequest();  
        return request;  
    }     
    /** 
     * 获取当前请求session 
     * @return 
     */  
    public static HttpSession getHttpSession(){  
        return getHttpServletRequest().getSession();  
    }  
}  

web.xml 加入监听


<!-- 5. spring 注册监听，获取上下文中的 HttpServletRequest 对象（对 Global 支持）  -->

<listener>
    <listener-class>
        org.springframework.web.context.request.RequestContextListener
    </listener-class>
</listener>

https://blog.csdn.net/hellozhxy/article/details/80775832