No thread-bound request found: Are you referring to request attributes outside of an actual web requ

淩亂°似流年 2021-06-22 15:38 2694阅读 0赞

今天收到一个bug，乍一看是个陌生面孔。

#### 报错信息 ####

No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet/DispatcherPortlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.

看了一下是在spring-web中RequestContextHolder.currentRequestAttributes方法抛出来的。

/** * Return the RequestAttributes currently bound to the thread. * <p>Exposes the previously bound RequestAttributes instance, if any. * Falls back to the current JSF FacesContext, if any. * @return the RequestAttributes currently bound to the thread * @throws IllegalStateException if no RequestAttributes object * is bound to the current thread * @see #setRequestAttributes * @see ServletRequestAttributes * @see FacesRequestAttributes * @see javax.faces.context.FacesContext#getCurrentInstance() */
    	public static RequestAttributes currentRequestAttributes() throws IllegalStateException { 
    		RequestAttributes attributes = getRequestAttributes();
    		if (attributes == null) { 
    			if (jsfPresent) { 
    				attributes = FacesRequestAttributesFactory.getFacesRequestAttributes();
    			}
    			if (attributes == null) { 
    				throw new IllegalStateException("No thread-bound request found: " +
    						"Are you referring to request attributes outside of an actual web request, " +
    						"or processing a request outside of the originally receiving thread? " +
    						"If you are actually operating within a web request and still receive this message, " +
    						"your code is probably running outside of DispatcherServlet/DispatcherPortlet: " +
    						"In this case, use RequestContextListener or RequestContextFilter to expose the current request.");
    			}
    		}
    		return attributes;
    	}

看了方法注释说，如果当前线程没有绑定请求request的属性，就会报这个错。

#### 问题排查 ####

可是我们有用到HttpServletRequest相关的属性，怎么会报这个错呢？  
最终发现，我们私库里的代码，根据国际化获取提示信息的一段。

/** * 获取国际化消息. * * @param code * 代码 * @param args * 参数 * @return 国际化消息 */
        public String getMessage(String code, Object... args) { 
            Locale locale = localeResolver.resolveLocale(WebUtil.getRequest());
            return messageSource.getMessage(code, args, locale);
        }

其中WebUtil.getRequest()就是获取这个RequestAttributes的方法。

/** * Gets the request. * * @return the request */
        public static HttpServletRequest getRequest() { 
            ServletRequestAttributes attr = (ServletRequestAttributes) RequestContextHolder.currentRequestAttributes();
            return attr.getRequest();
        }

发现问题所在了。

#### 问题分析 ####

在之前的方法调用的没有发现这个问题，原因是请求中会包含HttpServletRequest对象，不会报错。而我这次的调用是将流程移到异步线程中执行，中途丢失了HttpServletRequest对象，所以就获取不到，报这个错。

#### 解决方法 ####

本次我是直接调了另外一个方法，跳过了获取Locale的步骤。

/** * 获取国际化消息. * @param code 代码 * @param args 参数 * @return 国际化消息 */
        public String getMessageWithDefaultLocale(String code, Object... args) { 
            return messageSource.getMessage(code, args, Locale.SIMPLIFIED_CHINESE);
        }

另外就需要考虑将HttpServletRequest对象设置到异步线程池的线程中。