hibernate annotations 几种配置

1、spring orm support 与原来使用LocalSessionFactoryBean相比，变动不大（AnnotationSessionFactoryBean本来就是从LocalSessionFactoryBean类继承过来的嘛） <!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>--> 1    < bean 2         id="sessionFactory" 3          class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean" 4          parent="AbstractSessionFactory"> 5         <property name="annotatedClasses"> 6             <list> 7                 <value>xxx.xxx.xxx.domain.Accountvalue> 8             list> 9         property> 10     bean> 11     < bean 12         id="AbstractSessionFactory" 13          class="org.springframework.orm.hibernate3.LocalSessionFactoryBean" 14          abstract="true"> 15         < property 16             name="dataSource" 17              ref="DataSource" /> 18         <property name="hibernateProperties"> 19             <props> 20                 <prop key="hibernate.dialect">${hibernate.dialect}prop> 21                 <prop key="hibernate.show_sql">${hibernate.show_sql}prop> 22                 <prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}prop> 23                 <prop key="hibernate.cache.use_query_cache">${hibernate.cache.use_query_cache}prop> 24                 <prop key="hibernate.cache.provider_class">${hibernate.cache.provider_class}prop> 25             props> 26         property> 27         < property 28             name="lobHandler" 29              ref="DefaultLobHandler" /> 30     bean> 2、id的配置 非常简单，在id的getter上面加个“@Id”就可以了。此时采用的id策略是javax.persistence.GenerationType.AUTO，也可以再加上“@GeneratedValue(generator =GenerationType.IDENTITY|GenerationType.SEQUENCE|GenerationType.TABLE)”换成其它策略。 我的应用采用的是hibernate的uuid策略，就不得不在这儿使用hibernate的扩展了 <!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>-->   @Id    @Column(length = 32)    @GeneratedValue(generator = "system-uuid")    @GenericGenerator(name = "system-uuid", strategy = "uuid") 我在公司配置的是 @Id @GenericGenerator(name = "hibernate-uuid", strategy = "uuid") @GeneratedValue(generator = "hibernate-uuid") private String id;   3、级联策略 在ejb3-persistence.jar中只定义了ALL、MERGE、PERSIST、REFRESH、REMOVE，比较恶心的就是，删除对象的时候，并不会级联删除关联对象，而是用update xx set parent_id=null where parent_id=?这类语句把关系干掉了事。不得已，在这儿用了hibernate的DELETE_ORPHAN。 <!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>-->    @OneToMany(targetEntity = Attachment.class )    @Cascade(value = {org.hibernate.annotations.CascadeType.DELETE_ORPHAN,        org.hibernate.annotations.CascadeType.ALL})    @JoinColumn(name = "info_id") 4、CACHE ejb3-persistence.jar里面没有找到cache的配置，继续请出hibernate来干活 <!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>--> import org.hibernate.annotations.Cache; import org.hibernate.annotations.CacheConcurrencyStrategy; @Entity @Table(name = "T_INFO" ) @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE) 5、自定义字段类型 我的POJO中有一个private String content;的属性，按ejb3配成@Lob后，被处理成了text类型，text 64k的存储容量还是比较可怜了。 <!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>-->    @Lob    @Column(columnDefinition = "LongText")