学步园

在对hibernate中的关联表进行数据更新时 会对数据机型脏数据检查

该操作的主要方法：dirtyCheck

该位于org.hibernate.event.def.DefaultFlushEntityEventListener

protected void dirtyCheck(FlushEntityEvent event) throws HibernateException {<br /> // 监听待检查的 实体EntityBean<br /> final Object entity = event.getEntity();<br /> // 获取EntityBean属性列表 :<br /> // 利用此方式可以查看 hibernate 生成的带参数的sql的具体值<br /> final Object[] values = event.getPropertyValues();</p> <p> final SessionImplementor session = event.getSession();<br /> final EntityEntry entry = event.getEntityEntry();<br /> final EntityPersister persister = entry.getPersister();<br /> final Serializable id = entry.getId();<br /> final Object[] loadedState = entry.getLoadedState();</p> <p> int[] dirtyProperties = session.getInterceptor().findDirty(<br /> entity,<br /> id,<br /> values,<br /> loadedState,<br /> persister.getPropertyNames(),<br /> persister.getPropertyTypes()<br /> );</p> <p> event.setDatabaseSnapshot(null);</p> <p> final boolean interceptorHandledDirtyCheck;<br /> boolean cannotDirtyCheck;</p> <p> if ( dirtyProperties==null ) {<br /> // Interceptor returned null, so do the dirtycheck ourself, if possible<br /> interceptorHandledDirtyCheck = false;</p> <p> cannotDirtyCheck = loadedState==null; // object loaded by update()<br /> if ( !cannotDirtyCheck ) {<br /> // dirty check against the usual snapshot of the entity<br /> dirtyProperties = persister.findDirty( values, loadedState, entity, session );</p> <p> }<br /> else {<br /> // dirty check against the database snapshot, if possible/necessary<br /> final Object[] databaseSnapshot = getDatabaseSnapshot(session, persister, id);<br /> if ( databaseSnapshot != null ) {<br /> dirtyProperties = persister.findModified(databaseSnapshot, values, entity, session);<br /> cannotDirtyCheck = false;<br /> event.setDatabaseSnapshot(databaseSnapshot);<br /> }<br /> }<br /> }<br /> else {<br /> // the Interceptor handled the dirty checking<br /> cannotDirtyCheck = false;<br /> interceptorHandledDirtyCheck = true;<br /> }</p> <p> event.setDirtyProperties(dirtyProperties);<br /> event.setDirtyCheckHandledByInterceptor(interceptorHandledDirtyCheck);<br /> event.setDirtyCheckPossible(!cannotDirtyCheck);</p> <p> }