code: public static byte[] getBytes(Object obj) throws IOException {
  		ByteArrayOutputStream bos = new ByteArrayOutputStream();
  		ObjectOutputStream oos = new ObjectOutputStream(bos);
  		oos.writeObject(obj);
  		oos.flush();
  		oos.close();
  		bos.close();
  		byte[] data = bos.toByteArray();
  		return data;
  	}
docs: 从对象转变为字节数组
  
  @param obj 需要转换的对象
  
  @return 字节数组
  
  @throws IOException 异常处理