java讀取文件內容，文件頭有"\ufeff"

"\ufeff"是UTF-8 BOM編碼的文件頭，代表該文件按照什么字節順序排序

調用java的工具類[

UnicodeInputStream 

]即可解決這個問題

 //第二個參數targetEncoding為null時在getDetectedEncoding方法中會自動檢測編碼類型
 UnicodeInputStream unicodeInputStream = new UnicodeInputStream(inputStream, null);
 String enc = unicodeInputStream.getDetectedEncoding();
 //UnicodeInputStream內部由PushbackInputStream實現，跳過了無意義的文件頭
 bufferedReader = new BufferedReader(new InputStreamReader(unicodeInputStream, enc));