С нуля разбираюсь с хибером.
Написал 3 класса:
| Код |
@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@DiscriminatorColumn(name = "DISCRIMINATOR", discriminatorType = DiscriminatorType.STRING)
public abstract class AbstractEntity implements Serializable {
@Id
@GeneratedValue(strategy= GenerationType.AUTO)
protected Long id;
protected String model;
protected String marka;
protected int year;
protected double engineVolume;
protected double enginePower;
protected double tankVolume;
protected double cost;
public Long getId() {
return id;
}
public String getModel() {
return model;
}
public void setModel(String model) {
this.model = model;
}
public String getMarka() {
return marka;
}
public void setMarka(String marka) {
this.marka = marka;
}
public int getYear() {
return year;
}
public void setYear(int year) {
this.year = year;
}
public double getEngineVolume() {
return engineVolume;
}
public void setEngineVolume(double engineVolume) {
this.engineVolume = engineVolume;
}
public double getEnginePower() {
return enginePower;
}
public void setEnginePower(double enginePower) {
this.enginePower = enginePower;
}
public double getTankVolume() {
return tankVolume;
}
public void setTankVolume(double tankVolume) {
this.tankVolume = tankVolume;
}
public double getCost() {
return cost;
}
public void setCost(double cost) {
this.cost = cost;
}
}
|
| Код |
@Entity
@DiscriminatorValue("AUTO")
public class Auto extends AbstractEntity {
private String type;
}
|
| Код |
@Entity
@DiscriminatorValue("MOTO")
public class Moto extends AbstractEntity {
private String use;
public String getUse() {
return use;
}
public void setUse(String use) {
this.use = use;
}
}
|
Дальше настройка хибера:
| Код |
<hibernate-configuration>
<session-factory>
<!-- Database connection settings -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost:3306/automoto?createDatabaseIfNotExist=true&useUnicode=true&characterEncoding=utf-8</property>
<property name="connection.username">foo</property>
<property name="connection.password">bar</property>
<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<!-- Drop and re-create the database schema on startup -->
<property name="hbm2ddl.auto">update</property>
<mapping class="psu.yanukov.oop.core.domain.Auto"/>
<mapping class="psu.yanukov.oop.core.domain.Moto"/>
</session-factory>
</hibernate-configuration>
|
Простой класс для теста:
| Код |
public class Test {
public static void main(String[] args) {
// TODO Auto-generated method stub
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction();
//Auto auto = new Auto();
//auto.setCost(12);
//auto.setMarka("ford");
Moto moto = new Moto();
moto.setCost(12);
moto.setEnginePower(13);
moto.setEngineVolume(14);
moto.setMarka("marka");
moto.setModel("model");
moto.setTankVolume(15);
moto.setYear(1234);
moto.setUse("use");
moto.setCost(15);
//session.save(auto);
session.save(moto);
session.getTransaction().commit();
session.close();
}
}
|
Вылетает с ошибкой
| Код |
Hibernate: insert into AbstractEntity (cost, enginePower, engineVolume, marka, model, tankVolume, year) values (?, ?, ?, ?, ?, ?, ?)
Hibernate: insert into Moto (use, id) values (?, ?)
Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not insert: [psu.yanukov.oop.core.domain.Moto]
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:92)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2454)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2854)
at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:71)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:320)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:203)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:129)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:210)
at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:56)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:195)
at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:50)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93)
at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:713)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:701)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:697)
at psu.yanukov.oop.core.Test.main(Test.java:32)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'use, id) values ('use', 1)' at line 1
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
at com.mysql.jdbc.Util.getInstance(Util.java:384)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1054)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3566)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3498)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1959)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2113)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2568)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2113)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2409)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2327)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2312)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2437)
... 15 more
|
Если же раскоментить строчки для Auto, а для Moto закоментить, то все отработает на ура... так в чем разница в этих классах??? |
