字節流轉化爲字符流
FileInputStream fileInputStream = new FileInputStream("d:/text.txt"); // 定義一個指向D:/TEXT.TXT 的字節流
InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream);
//字節流轉換成InputStreamReader
BufferedReader bufferedReader = new BufferedReader(inputSteamReader);
//InputStreamReader 轉換成帶緩存的bufferedReader