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
".tsp": "application/dsptype", ".tsv": "text/tab-separated-values", ".ttf": "application/octet-stream", ".ttz": "application/t-time", ".txt": "text/plain", ".uls": "text/iuls", ".ult": "audio/x-mod", ".ustar": "application/x-ustar", ".uu": "application/x-uuencode", ".uu