java读取文件内容，文件头有"ufeff"

"ufeff"是UTF-8 BOM编码的文件头，代表该文件按照什么字节顺序排序

调用java的工具类[

UnicodeInputStream 

]即可解决这个问题

 //第二个参数targetEncoding为null时在getDetectedEncoding方法中会自动检测编码类型
 UnicodeInputStream unicodeInputStream = new UnicodeInputStream(inputStream, null);
 String enc = unicodeInputStream.getDetectedEncoding();
 //UnicodeInputStream内部由PushbackInputStream实现，跳过了无意义的文件头
 bufferedReader = new BufferedReader(new InputStreamReader(unicodeInputStream, enc));