因為框架的不同獲取request物件的方式也會有改變：

springMVC中獲取request的方式有三種：

1.使用註解：

@Autowired
private  HttpServletRequest request;

@RequestMapping("/test")
@ResponseBody
public void saveTest(HttpServletRequest req, HttpServletResponse resp){
　　
}

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

HttpServletRequest req = ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest();
HttpServletResponse resp = ((ServletWebRequest)RequestContextHolder.getRequestAttributes()).getResponse();

RequestContextListener實現了 ServletRequestListener ,在其覆蓋的requestInitialized(ServletRequestEvent requestEvent)方法中,將request最終設定到了RequestContextHolder中.

public class RequestContextListener implements ServletRequestListener {

    private static final String REQUEST_ATTRIBUTES_ATTRIBUTE =
            RequestContextListener.class.getName() + ".REQUEST_ATTRIBUTES";


    @Override
    public void requestInitialized(ServletRequestEvent requestEvent) {
        if (!(requestEvent.getServletRequest() instanceof HttpServletRequest)) {
            throw new IllegalArgumentException(
                    "Request is not an HttpServletRequest: " + requestEvent.getServletRequest());
        }
        HttpServletRequest request = (HttpServletRequest) requestEvent.getServletRequest();//從事件物件中獲取request物件
 

        ServletRequestAttributes attributes = new ServletRequestAttributes(request);//將request設定到servletRequestAttributes中
        request.setAttribute(REQUEST_ATTRIBUTES_ATTRIBUTE, attributes);//反過來將servletRequestAttributes設定到request中
        LocaleContextHolder.setLocale(request.getLocale());
        RequestContextHolder.setRequestAttributes(attributes);//再將servletRequestAttributes設定到requestContextHolder中
    }

HttpServletRequest request = ServletActionContext.getRequest();