【原创】经验分享：一个Content-Length引发的血案(almost....)

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class ChannelFilter implements Filter {\n public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {\n if (servletRequest instanceof HttpServletRequest) {\n requestWrapper = new RequestWrapper((HttpServletRequest)servletRequest);\n log.info(\"Http RequestURL : {}, Method : {}, RequestParam : {}, RequestBody : {}\", new Object[]{((HttpServletRequest)servletRequest).getRequestURL(), ((HttpServletRequest)servletRequest).getMethod(), JSON.toJSON(servletRequest.getParameterMap()), ((RequestWrapper)requestWrapper).getBody()});\n }\n\n\n filterChain.doFilter((ServletRequest)requestWrapper, servletResponse);\n }\n\n\n public void destroy() {\n }\n}\n\npublic class RequestWrapper extends HttpServletRequestWrapper {\n private static final Logger log = LoggerFactory.getLogger(RequestWrapper.class);\n private final String body;\n\n public RequestWrapper(HttpServletRequest request) {\n super(request);\n 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直到超时，这也是为什么我们每次"},{"type":"codeinline","content":[{"type":"text","text":"feign"}]},{"type":"text","text":"请求都会超时的原因。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"但是如果服务请求方配置了传递的"},{"type":"codeinline","content":[{"type":"text","text":"Content-Length"}]},{"type":"text","text":"为空呢？这里会构造一个"},{"type":"codeinline","content":[{"type":"text","text":"org.apache.coyote.http11.filters.VoidInputFilter"}]},{"type":"text","text":"，这个拦截器的构造在上面"},{"type":"codeinline","content":[{"type":"text","text":"Http11Processor.prepareRequest()"}]},{"type":"text","text":"图示中已经标明："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/e7/e7ebf0b131e261dd4cc101a43887ee26.png","alt":"NioBlockingSelector.read().png","title":null,"style":null,"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"显而易见，这里直接返回-1，不会再去调用"},{"type":"codeinline","content":[{"type":"text","text":"NioBlockingSelector.read()"}]},{"type":"text","text":" 方法了，所以成功解决此问题，这也是问题的关键所在。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"总结"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"这里没有过多的去介绍"},{"type":"codeinline","content":[{"type":"text","text":"Content-Length"}]},{"type":"text","text":"的概念，默许大家都知道这个，如果不太清楚的还可以参考："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"https://blog.piaoruiqing.com/2019/09/08/do-you-know-content-length/"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"一个简单的"},{"type":"codeinline","content":[{"type":"text","text":"Content-Length"}]},{"type":"text","text":"确实难住了我，请求的不规范才是这次问题的真正原因。而排查出来这个问题也花费了很多时间，不过这些都是挺值得的，一个人的成长离不开各种问题的洗礼，希望大家阅读完也会有所收获。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"欢迎关注："}]},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/11/1115cca6fcac752923b30f3805040567.png","alt":"原创干货分享.png","title":null,"style":null,"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}}]}