1. 确定json文件是UTF-8 无BOM编码的的。如果有BOM，会在读取第一行的时候出现乱码。
Per “fs.readFileSync(filename, ‘utf8’) doesn’t strip BOM markers #1918”, fs.readFile is
working as designed: BOM is not stripped from the header of the UTF-8 file, if it exists. It at the discretion o
