將文件File轉換成byte數組

/**
     * 將文件轉換成byte數組
     * @param filePath
     * @return
     */
    public static byte[] File2byte(File tradeFile){
        byte[] buffer = null;
        try
        {
            FileInputStream fis = new FileInputStream(tradeFile);
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            byte[] b = new byte[1024];
            int n;
            while ((n = fis.read(b)) != -1)
            {
                bos.write(b, 0, n);
            }
            fis.close();
            bos.close();
            buffer = bos.toByteArray();
        }catch (FileNotFoundException e){
            e.printStackTrace();
        }catch (IOException e){
            e.printStackTrace();
        }
        return buffer;
    }

public static void main( String[] args ){
        // TODO Auto-generated method stub
         String filePath = "C:\\Users\\24991\\Desktop\\數據交換系統文檔\\二進制文件\\20190120\\TRX011211002.20190120.003";
        try {
            File file1 = new File(filePath);
            byte[] bytes = File2byte(file1);
            System.out.println(bytes);
        } catch (Exception  e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }  

    }