我有两个名为“Padre”和“Figlio”的实体 Padre是老板，Figlio是小孩 Padre的主键有两列，PADREK1和PADREK2，都是CHAR（20） Figlio的主键有四列： PADREPADREK1（外国）CHAR（20） PADREPADREK2（外国）CHAR（20） FIGLIOK1 CHAR（20） FIGLIOK2 CHAR（20）
这是我的实体类的代码
public class PadreBean extends BaseEntityBean3 implements Serializable
{
@EmbeddedId
PadrePK iPadrePK;
@Column(name = "DESCRIPTION")
private String iDescription;
@Column(name = "ABSUNIQUEID")
private long iABSUniqueId;
@OneToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
@JoinColumns(
{
@JoinColumn(name = "ABSOUTQUEUENAME", nullable = true)
})
private ABSOutQueueBean iAbsOutQueueBean;
@OneToMany(fetch = FetchType.LAZY)
@JoinColumns({
@JoinColumn(name = "PADREPADREK1", referencedColumnName = "PADREK1"),
@JoinColumn(name = "PADREPADREK2", referencedColumnName = "PADREK2")
})
List iFiglioBeans;
......
iFiglioBeans是孩子们的集合
问题是： 如果Padre的主键列都使用全部20个字符填充，则一切正常; id padre的主键列未完全填充Hibernate会加载集合 但加载后它会清除其内容。
我已经激活了Hibernate日志记录，当我的代码访问子集合时，我看到：
[org.hibernate.engine.jdbc.internal.LogicalConnectionImpl] (http-localhost/127.0.0.1:8080-1) Obtaining JDBC connection
[org.hibernate.engine.jdbc.internal.LogicalConnectionImpl] (http-localhost/127.0.0.1:8080-1) Obtained JDBC connection
[org.hibernate.loader.Loader] (http-localhost/127.0.0.1:8080-1) Result set contains (possibly empty) collection: [com.dat.abs.run.PadreBean.iFiglioBeans#component[iPadreK1,iPadreK2]{iPadreK2=p1, iPadreK1=p1}]
[org.hibernate.loader.Loader] (http-localhost/127.0.0.1:8080-1) Result set row: 0
[org.hibernate.loader.Loader] (http-localhost/127.0.0.1:8080-1) Result row: EntityKey[com.dat.abs.run.FiglioBean#component[iFiglioK1,iFiglioK2,iPadrePadreK1,iPadrePadreK2]{iFiglioK2=1 , iPadrePadreK1=p1 , iFiglioK1=1 , iPadrePadreK2=p1 }]
[org.hibernate.loader.Loader] (http-localhost/127.0.0.1:8080-1) Found row of collection: [com.dat.abs.run.PadreBean.iFiglioBeans#component[iPadreK1,iPadreK2]{iPadreK2=p1 , iPadreK1=p1 }]
[org.hibernate.loader.Loader] (http-localhost/127.0.0.1:8080-1) Result set row: 1
[org.hibernate.loader.Loader] (http-localhost/127.0.0.1:8080-1) Result row: EntityKey[com.dat.abs.run.FiglioBean#component[iFiglioK1,iFiglioK2,iPadrePadreK1,iPadrePadreK2]{iFiglioK2=f1 , iPadrePadreK1=p1 , iFiglioK1=f1 , iPadrePadreK2=p1 }]
[org.hibernate.loader.Loader] (http-localhost/127.0.0.1:8080-1) Found row of collection: [com.dat.abs.run.PadreBean.iFiglioBeans#component[iPadreK1,iPadreK2]{iPadreK2=p1 , iPadreK1=p1 }]
[org.hibernate.engine.internal.TwoPhaseLoad] (http-localhost/127.0.0.1:8080-1) Resolving associations for [com.dat.abs.run.FiglioBean#component[iFiglioK1,iFiglioK2,iPadrePadreK1,iPadrePadreK2]{iFiglioK2=1 , iPadrePadreK1=p1 , iFiglioK1=1 , iPadrePadreK2=p1 }]
[org.hibernate.engine.internal.TwoPhaseLoad] (http-localhost/127.0.0.1:8080-1) Done materializing entity [com.dat.abs.run.FiglioBean#component[iFiglioK1,iFiglioK2,iPadrePadreK1,iPadrePadreK2]{iFiglioK2=1 , iPadrePadreK1=p1 , iFiglioK1=1 , iPadrePadreK2=p1 }]
[org.hibernate.engine.internal.TwoPhaseLoad] (http-localhost/127.0.0.1:8080-1) Resolving associations for [com.dat.abs.run.FiglioBean#component[iFiglioK1,iFiglioK2,iPadrePadreK1,iPadrePadreK2]{iFiglioK2=f1 , iPadrePadreK1=p1 , iFiglioK1=f1 , iPadrePadreK2=p1 }]
[org.hibernate.engine.internal.TwoPhaseLoad] (http-localhost/127.0.0.1:8080-1) Done materializing entity [com.dat.abs.run.FiglioBean#component[iFiglioK1,iFiglioK2,iPadrePadreK1,iPadrePadreK2]{iFiglioK2=f1 , iPadrePadreK1=p1 , iFiglioK1=f1 , iPadrePadreK2=p1 }]
[org.hibernate.engine.loading.internal.CollectionLoadContext] (http-localhost/127.0.0.1:8080-1) 2 collections were found in result set for role: com.dat.abs.run.PadreBean.iFiglioBeans
[org.hibernate.engine.loading.internal.CollectionLoadContext] (http-localhost/127.0.0.1:8080-1) Collection fully initialized: [com.dat.abs.run.PadreBean.iFiglioBeans#component[iPadreK1,iPadreK2]{iPadreK2=p1, iPadreK1=p1}]
[org.hibernate.engine.loading.internal.CollectionLoadContext] (http-localhost/127.0.0.1:8080-1) Collection fully initialized: [com.dat.abs.run.PadreBean.iFiglioBeans#component[iPadreK1,iPadreK2]{iPadreK2=p1 , iPadreK1=p1 }]
[org.hibernate.engine.loading.internal.CollectionLoadContext] (http-localhost/127.0.0.1:8080-1) 2 collections initialized for role: com.dat.abs.run.PadreBean.iFiglioBeans
[org.hibernate.engine.jdbc.internal.LogicalConnectionImpl] (http-localhost/127.0.0.1:8080-1) Releasing JDBC connection
[org.hibernate.engine.jdbc.internal.LogicalConnectionImpl] (http-localhost/127.0.0.1:8080-1) Released JDBC connection
[org.hibernate.loader.Loader] (http-localhost/127.0.0.1:8080-1) Done loading collection
[org.hibernate.event.internal.AbstractFlushingEventListener] (http-localhost/127.0.0.1:8080-1) Processing flush-time cascades
[org.hibernate.event.internal.AbstractFlushingEventListener] (http-localhost/127.0.0.1:8080-1) Dirty checking collections
[org.hibernate.engine.internal.Collections] (http-localhost/127.0.0.1:8080-1) Collection found: [com.dat.abs.run.PadreBean.iFiglioBeans#component[iPadreK1,iPadreK2]{iPadreK2=p1, iPadreK1=p1}], was: [com.dat.abs.run.PadreBean.iFiglioBeans#component[iPadreK1,iPadreK2]{iPadreK2=p1, iPadreK1=p1}] (initialized)
[org.hibernate.engine.internal.Collections] (http-localhost/127.0.0.1:8080-1) Found collection with unloaded owner: [com.dat.abs.run.PadreBean.iFiglioBeans#component[iPadreK1,iPadreK2]{iPadreK2=p1 , iPadreK1=p1 }]
[org.hibernate.event.internal.AbstractFlushingEventListener] (http-localhost/127.0.0.1:8080-1) Flushed: 0 insertions, 0 updates, 0 deletions to 4 objects
[org.hibernate.event.internal.AbstractFlushingEventListener] (http-localhost/127.0.0.1:8080-1) Flushed: 0 (re)creations, 0 updates, 0 removals to 2 collections
[org.hibernate.internal.util.EntityPrinter] (http-localhost/127.0.0.1:8080-1) Listing entities:
[org.hibernate.internal.util.EntityPrinter] (http-localhost/127.0.0.1:8080-1) com.dat.abs.run.FiglioBean{iDescrizioneFiglio= , iFiglioPK=component[iFiglioK1,iFiglioK2,iPadrePadreK1,iPadrePadreK2]{iFiglioK2=1 , iPadrePadreK1=p1 , iFiglioK1=1 , iPadrePadreK2=p1 }, iABSUniqueId=249}
[org.hibernate.internal.util.EntityPrinter] (http-localhost/127.0.0.1:8080-1) com.dat.abs.run.ABSOutQueueBean{iCreationDateTime=2012-02-17 07:51:10.0, iLastUpdateUser=null, iCreationUser=system , iLastUpdateDateTime=null, iPrintServiceName=null, iId=component[iName]{iName=#01 }, iDescription=01 }
[org.hibernate.internal.util.EntityPrinter] (http-localhost/127.0.0.1:8080-1) com.dat.abs.run.FiglioBean{iDescrizioneFiglio=f1 , iFiglioPK=component[iFiglioK1,iFiglioK2,iPadrePadreK1,iPadrePadreK2]{iFiglioK2=f1 , iPadrePadreK1=p1 , iFiglioK1=f1 , iPadrePadreK2=p1 }, iABSUniqueId=248}
[org.hibernate.internal.util.EntityPrinter] (http-localhost/127.0.0.1:8080-1) com.dat.abs.run.PadreBean{iPadrePK=component[iPadreK1,iPadreK2]{iPadreK2=p1, iPadreK1=p1}, iAbsOutQueueBean=com.dat.abs.run.ABSOutQueueBean#component[iName]{iName=#01 }, iDescription=p1 , iABSUniqueId=247, iFiglioBeans=[]}
[org.hibernate.engine.jdbc.internal.LogicalConnectionImpl] (http-localhost/127.0.0.1:8080-1) Releasing JDBC connection
[org.hibernate.engine.jdbc.internal.LogicalConnectionImpl] (http-localhost/127.0.0.1:8080-1) Aggressively releasing JDBC connection
正如您所看到的，Hibernate首先加载了孩子，但是在清除它之后。 请参阅该行前面附带的日志：找到带有已卸载所有者的集合：消息
问题是DBM用来填充CHARs列的空白区域，我已经说过了，如果我在我的键列中插入所有字符也一样。
那么，是否有一个解决方案让Hibernate的子集合使用CHAR列作为未完全填充的主键？
提前感谢您的时间
答案 0 :(得分：1)
我已经解决了编写自己的用户类型的问题。 我在这里发帖因为可能对其他人有用。 使用db2 9.x和Oracle 12c进行测试
package com.dat.abs.run;
import java.io.Serializable;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;
import org.hibernate.HibernateException;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.usertype.UserType;
public class ABSChar implements UserType
{
public int[] sqlTypes()
{
return new int[]
{
Types.CHAR,
};
}
public Class returnedClass()
{
return String.class;
}
public boolean equals(Object x, Object y) throws HibernateException
{
return (x == y) || (x != null && y != null && (x.equals(y)));
}
public Object deepCopy(Object value) throws HibernateException
{
if (value == null)
return null;
return new String((String) value);
}
public boolean isMutable()
{
return false;
}
@Override
public int hashCode(Object aValue) throws HibernateException
{
return aValue.hashCode();
}
@Override
public Object replace(Object aOriginal, Object aTarget, Object aOwner) throws HibernateException
{
return aOriginal;
}
@Override
public Object assemble(Serializable aChaced, Object aOwner) throws HibernateException
{
return aChaced;
}
@Override
public Serializable disassemble(Object aValue) throws HibernateException
{
return (Serializable) aValue;
}
@Override
public Object nullSafeGet(ResultSet aRs, String[] aNames, SessionImplementor aSession, Object aOwner) throws HibernateException, SQLException
{
String val = aRs.getString(aNames[0]);
if (val == null)
{
return null;
}
return val.trim();
}
@Override
public void nullSafeSet(PreparedStatement aStatament, Object aValue, int aIndex, SessionImplementor aSession) throws HibernateException, SQLException
{
aStatament.setString(aIndex, (String) aValue);
}
}
这是使用bean类中的类型
@Type(type = "com.dat.abs.run.ABSChar")
@Column(name = "PADREPADREK1", length = 20)
private String iPadrePadreK1;
@Type(type = "com.dat.abs.run.ABSChar")
@Column(name = "PADREPADREK2", length = 20)
private String iPadrePadreK2;
@Type(type = "com.dat.abs.run.ABSChar")
@Column(name = "FIGLIOK1", length = 20)
private String iFiglioK1;
@Type(type = "com.dat.abs.run.ABSChar")
@Column(name = "FIGLIOK2", length = 20)