private Element createElementByPo(DocumentFactory factory, String entityName)
			throws ClassNotFoundException, DBException {
		Class<?> entity = null;
		entity = Class.forName(entityName);
		Field[] fields = entity.getDeclaredFields();
		boolean flag = false;
		for (Field field : fields) {
			Annotation primaryAnnotation = field
					.getAnnotation(PrimaryKeysAnnotation.class);
			if (primaryAnnotation != null) {
				flag = true;
			}
		}
		if (flag == false)
			// { return null;}
			throw new DBException(entityName + "没有配置主键注解,请重新配置好！");

		// System.out.println(this.createElementIfPrimaryKeyExists(factory,
		// entityName).asXML());
		return this.createElementIfPrimaryKeyExists(factory, entityName);

	}