code: public static <T> byte[] serialize(T obj) {
  		if (null == obj || false == (obj instanceof Serializable)) {
  			return null;
  		}
  
  		FastByteArrayOutputStream byteOut = new FastByteArrayOutputStream();
  		ObjectOutputStream oos = null;
  		try {
  			oos = new ObjectOutputStream(byteOut);
  			oos.writeObject(obj);
  			oos.flush();
  		} catch (Exception e) {
  			throw new UtilException(e);
  		} finally {
  			IoUtil.close(oos);
  		}
  		return byteOut.toByteArray();
  	}
docs: 序列化<br>
  对象必须实现Serializable接口
  
  @param <T> 对象类型
  @param obj 要被序列化的对象
  @return 序列化后的字节码