001.如何在控制层获取HttpServletRequest

1.通过注解获取（很简单，推荐）

public class HelloController {
  @Autowired  
  protected HttpServletRequest request; //这里可以获取到request
}

2.在web.xml中配置一个监听

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

Java代码

HttpServletRequest request = 
((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest();

3.直接在参数中传递（此方法不好用，不建议使用）：

public String helloController(HttpServletRequest request)

4.我曾经使用的方式@ModelAttribute方式

public abstract class BaseController {
    
    protected HttpServletRequest request;
    protected HttpServletResponse response;
    protected HttpSession session;
    protected ServletContext application;
    
    @ModelAttribute
    public void initServletApi(HttpServletRequest request,HttpServletResponse response){
        this.request = request;
        this.response = response;
        this.session = request.getSession();
        this.application = this.session.getServletContext();
    }
}