当客户端想要下载文件时,nodejs服务端如何根据URL设置响应头的Content-Type类型
": "application/x-nif", ".nmz": "application/x-scream", ".nokia-op-logo": "image/vnd.nok-oplogo-color", ".npx": "application/x-netfpx", ".nsnd": "audio/nsnd", ".nva": "application/x-neva1", ".nws": "message/rfc822", ".oda": "application/oda", ".ogg": "audio/ogg", ".oom":