hibernate update 错误解决

update时候出现如下错误
org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session:
解决方法：
根据id得到缓存里的pojo对象，修改该对象，更新该对象

public void update(AppInfo appInfo){
		AppInfo ai = getAIById(appInfo.getId());
		ai.setAct(appInfo.getAct());
		ai.setApp_name(appInfo.getApp_name());
		ai.setApp_id(appInfo.getApp_id());
		ai.setInstall_ram_range(appInfo.getInstall_ram_range());
		ai.setPackage_name(appInfo.getPackage_name());
		ai.setSwitch_ram_range(appInfo.getSwitch_ram_range());
		Transaction ts = s.beginTransaction();
		s.update(ai);
		ts.commit();
	}