摘要：
```java /* * Copyright 2002-2011 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the Licen... 阅读全文
摘要：
428 Precondition Required (要求先决条件)，429 Too Many Requests (太多请求)，431 Request Header Fields Too Large (请求头字段太大)，511 Network Authentication Required (要求网络认证)。 阅读全文