SpringMVC的RequestContextHolder分析

为什么要分析这个RequestContextHolder?
首先,我们一般获取request和response都是在过滤器Filter,或者拦截器,或者controller层获取

但如果在service获取request和response,正常来说在service层是没有request的,当我们需要在service层获取request和response时，我们可以在RequestContextHolder中获取。

        //两个方法在没有使用JSF的项目中是没有区别的
        RequestAttributes requestAttributes = RequestContextHolder.currentRequestAttributes();
//                                            RequestContextHolder.getRequestAttributes();
        //从session里面获取对应的值
        String str = (String) requestAttributes.getAttribute("name",RequestAttributes.SCOPE_SESSION);

        HttpServletRequest request = ((ServletRequestAttributes)requestAttributes).getRequest();
        HttpServletResponse response = ((ServletRequestAttributes)requestAttributes).getResponse();

一般封装工具类

	/**
	 * 获取request
	 */
	public static HttpServletRequest getRequest() {
		return getRequestAttributes().getRequest();
	}

	/**
	 * 获取response
	 */
	public static HttpServletResponse getResponse() {
		return getRequestAttributes().getResponse();
	}

	/**
	 * 获取session
	 */
	public static HttpSession getSession() {
		return getRequest().getSession();
	}

	public static ServletRequestAttributes getRequestAttributes() {
		RequestAttributes attributes = RequestContextHolder.getRequestAttributes();
		return (ServletRequestAttributes) attributes;
	}

可参考文章:https://blog.csdn.net/u012706811/article/details/53432032