使用场景
entitylisteners在jpa中使用,如果你是mybatis是不可以用的
它的意义
对实体属性变化的跟踪,它提供了保存前,保存后,更新前,更新后,删除前,删除后等状态,就像是拦截器一样,你可以在拦截方法里重写你的个性化逻辑。
它的使用
定义接口,如实体追踪
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/** * 数据建立与更新. */ public interface dataentity { timestamp getdatecreated(); void setdatecreated(timestamp datecreated); timestamp getlastupdated(); void setlastupdated(timestamp lastupdated); long getdatecreatedon(); void setdatecreatedon( long datecreatedon); long getlastupdatedon(); void setlastupdatedon( long lastupdatedon); } |
定义跟踪器
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@slf4j @component @transactional public class dataentitylistener { @prepersist public void prepersist(dataentity object) throws illegalargumentexception, illegalaccessexception { timestamp now = timestamp.from(instant.now()); object.setdatecreated(now); object.setlastupdated(now); logger.debug( "save之前的操作" ); } @postpersist public void postpersist(dataentity object) throws illegalargumentexception, illegalaccessexception { logger.debug( "save之后的操作" ); } @preupdate public void preupdate(dataentity object) throws illegalargumentexception, illegalaccessexception { timestamp now = timestamp.from(instant.now()); object.setlastupdated(now); logger.debug( "update之前的操作" ); } @postupdate public void postupdate(dataentity object) throws illegalargumentexception, illegalaccessexception { logger.debug( "update之后的操作" ); } @preremove public void preremove(dataentity object) { logger.debug( "del之前的操作" ); } @postremove public void postremove(dataentity object) { logger.debug( "del之后的操作" ); } } |
实体去实现这个对应的跟踪接口
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@entitylisteners (dataentitylistener. class ) public class product implements dataentity { @override public timestamp getdatecreated() { return createtime; } @override public void setdatecreated(timestamp datecreated) { createtime = datecreated; } @override public timestamp getlastupdated() { return lastupdatetime; } @override public void setlastupdated(timestamp lastupdated) { this .lastupdatetime = lastupdated; } @override public long getdatecreatedon() { return createon; } @override public void setdatecreatedon( long datecreatedon) { createon = datecreatedon; } @override public long getlastupdatedon() { return lastupdateon; } @override public void setlastupdatedon( long lastupdatedon) { this .lastupdateon = lastupdatedon; } } |
上面代码将实现在实体保存时对 createtime , lastupdatetime 进行赋值,当实体进行更新时对 lastupdatetime 进行重新赋值的操作。
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:http://www.cnblogs.com/lori/p/10243256.html