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4.476K

· steviebraga

By a client demand, I needed to change the way Hibernate names the foreign key columns.

By default, Hibernate adds the referenced column as a suffix, for example, entity_id, but I needed to add the referenced column as a prefix so it'd be named as id_entity.

Instead of annotating all the fields with the @Column and use the name property, I decided to customize the way Hibernate names these columns. To do this I need to create a custom Naming Strategy.

In Hibernate 4.3.5. you need to create a org.hibernate.cfg.naming.NamingStrategyDelegator and a org.hibernate.cfg.naming.NamingStrategyDelegateAdapter and declare it in the persistence.xml file.

So here is how I solved it:

import java.io.Serializable;

import org.hibernate.cfg.naming.HbmNamingStrategyDelegate;
import org.hibernate.cfg.naming.NamingStrategyDelegate;
import org.hibernate.cfg.naming.NamingStrategyDelegator;

public class CustomNamingStrategyDelegator implements NamingStrategyDelegator, Serializable {

 private static final long serialVersionUID = -1880672539574785139L;

 public static final NamingStrategyDelegator DEFAULT_INSTANCE = new CustomNamingStrategyDelegator();

 private final NamingStrategyDelegate hbmNamingStrategyDelegate;
 private final NamingStrategyDelegate jpaNamingStrategyDelegate;

 public CustomNamingStrategyDelegator() {
 this( new HbmNamingStrategyDelegate(), new CustomJpaNamingStrategyDelegate() );
 }

 protected CustomNamingStrategyDelegator( NamingStrategyDelegate hbmNamingStrategyDelegate, NamingStrategyDelegate jpaNamingStrategyDelegate ) {
 this.hbmNamingStrategyDelegate = hbmNamingStrategyDelegate;
 this.jpaNamingStrategyDelegate = jpaNamingStrategyDelegate;
 }

 @Override
 public NamingStrategyDelegate getNamingStrategyDelegate( boolean isHbm ) {
 return isHbm ? hbmNamingStrategyDelegate : jpaNamingStrategyDelegate;
 }

}

import org.hibernate.AssertionFailure;
import org.hibernate.cfg.naming.JpaNamingStrategyDelegate;
import org.hibernate.internal.util.StringHelper;

public class CustomJpaNamingStrategyDelegate extends JpaNamingStrategyDelegate {

 private static final long serialVersionUID = 1294347082667342357L;

 @Override
 public String determineImplicitEntityAssociationJoinColumnName( String propertyEntityName, String propertyJpaEntityName, String propertyTableName, String referencedColumnName, String referencingPropertyName ) {

 final String header;
 if ( referencingPropertyName == null ) {
 header = determineEntityNameToUse( propertyEntityName, propertyJpaEntityName );
 } else {
 header = StringHelper.unqualify( referencingPropertyName );
 }
 if ( header == null ) {
 throw new AssertionFailure( "propertyJpaEntityName and referencingPropertyName cannot both be empty." );
 }
 return toPhysicalColumnName( referencedColumnName + "_" + header );
 }

 private String determineEntityNameToUse( String entityName, String jpaEntityName ) {
 if ( StringHelper.isNotEmpty( jpaEntityName ) ) {
 return jpaEntityName;
 } else {
 return StringHelper.unqualifyEntityName( entityName );
 }
 }

}

Then declare it in persistence.xml

<properties>
 ...

 <property name="hibernate.ejb.naming_strategy_delegator" value="package.CustomNamingStrategyDelegator"/>

 ...
</properties>

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