我想提出休眠的示例程序遵循本教程: http://www.myeclipseide.com/documentation/quickstarts/hibernateintroduction/決策樣本程序處於休眠
使用反向工程,我已經建立這種方法。 EventsDAO.java:
public Events findById(com.hibernate.EventsId i) {
log.debug("getting Events instance with id: " + i);
try {
Events instance = (Events) getSession().get(
"com.hibernate.Events", i);
return instance;
} catch (RuntimeException re) {
log.error("get failed", re);
throw re;
}
}
和從主類makiing調用此方法:
private static void listEvents()
{
EventsDAO dao= new EventsDAO();
Events events= dao.findById(1);
printEvents("Printing User,", events);
dao.getSession().close();
}
它給我錯誤上:活動事件= dao.findById(1); 因爲在這裏,我傳遞int。在EventsDAO.java中,它的類型是EventsID。
請建議。
爲surlac建議, 現在它給例外: 異常線程「main」 org.hibernate.id.IdentifierGenerationException:IDS該類必須手動分配調用save()之前:com.hibernate.Events
private static void addEvents()
{
Events events= new Events();
events.setUid(1);
events.setName("abc");
events.setDuration(123);
EventsDAO dao= new EventsDAO();
Transaction tx=dao.getSession().beginTransaction();
dao.save(events);
tx.commit();
dao.getSession().close();
}
這是給在這一行例外:
dao.save(events);
這裏是Events.hbm.xml文件:<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Mapping file autogenerated by MyEclipse Persistence Tools -->
<hibernate-mapping>
<class name="com.hibernate.Events" table="EVENTS" schema="APP">
<composite-id name="id" class="com.hibernate.EventsId">
<key-property name="uid" type="java.lang.Long"> <column name="UID" />
</key-property>
<key-property name="name" type="java.lang.String"> <column name="NAME" length="20" />
</key-property>
<key-property name="duration" type="java.lang.Integer"> <column name="DURATION" /> </key-property>
</composite-id>
</class>
</hibernate-mapping>
請幫忙。
請檢閱,一個例外是也即將 – user783160