字符流定義字符集

        BufferedReader bfr = new BufferedReader(
                new InputStreamReader(
                        new BufferedInputStream(
                                new FileInputStream("test.txt") 
                                    ),"UTF-8")
                );
        String line = bfr.readLine();
        System.out.println(line);

        line = bfr.readLine();
        System.out.println(line); // null,文件結尾
        bfr.close();