我把一个mp3文件转换成字节数组，然后从字节数组中读取，但它在第15行显示空指针异常我代码：

public class MainClass {
    static byte[] bytesarray = null;

    public static void main(String args[]) {
        try {
            FileInputStream fis = new FileInputStream("D:\\taxi.mp3");
            try {
                fis.read(bytesarray, 0, 32);
                System.out.println(bytesarray.length);
            } catch (IOException e) {
                e.printStackTrace();
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        ByteArrayInputStream in = new ByteArrayInputStream(bytesarray);
        for (int i = 0; i < 32; i++) {
            int c;
            while ((c = in.read()) != -1) {
                if (i == 0) {
                    System.out.print((char) c);
                } else {
                    System.out.print(Character.toUpperCase((char) c));
                }
            }
            System.out.println();

        }
    }
}