string(249) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%9F%AD%E8%B7%AF%E5%8F%AF%E5%88%86%E4%B8%BA%E5%87%A0%E7%A7%8D%E7%B1%BB%E5%9E%8B => Failed to connect to 101.89.117.144 port 38017: Connection refused"
短路可分为几种类型
