[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-5832) JPA Query and IdClass Causing NullPointerException

JPA Query and IdClass Causing NullPointerException -------------------------------------------------- Key: HHH-5832 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-5832 Project: Hibernate Core Issue Type: Bug Components: metamodel Affects Versions: 3.5.1 Environment: Hibernate version 3.5.1 and Oracle 10g. Reporter: Erich Heard We had an issue when building queries dynamically with JPA objects when we accessed an @Id property of an entity class that used @IdClass. Under these conditions, Path.get( ) would return null. Here is a short illustration: The entity was specified like: @Entity // snipped more annotations @IdClass( RetailerId.class ) public class Retailer { @Id private String retailerId; public String getRetailerId( ) { return this.retailerId; } public void setRetailerId( String value ) { this.retailerId = value; } @Id private String divisionCode; public String getDivisionCode( ) { return this.divisionCode; } public void setDivisionCode( String value ) { this.divisionCode = value; } // snipped other attributes } And the ID class was specified like: @Embeddable public class RetailerId implements Serializable { private static final long serialVersionUID = -2639451633891197777L; @Column( name = "RETLR_ID", nullable = false, length = 7 ) private String retailerId; public String getRetailerId( ) { return this.retailerId; } public void setRetailerId( String value ) { this.retailerId = value; } @Column( name = "DIV_CDE", nullable = false, length = 2 ) private String divisionCode; public String getDivisionCode( ) { return this.divisionCode; } public void setDivisionCode( String value ) { this.divisionCode = value; } // snipped implementations of Serializable methods } The code that caused the error condition: CriteriaQuery<RetailerConfigurationPreference> query = cb.createQuery(RetailerConfigurationPreference.class); Root<RetailerConfigurationPreference> root = query.from(RetailerConfigurationPreference.class); Predicate predicate = root.get("retailer").get("retailerId").in(retailerIds); In this case, the 'get("retailerId")' would return null. To get around this issue, I altered the class org.hibernate.ejb.metamodel.AbstractIdentifiableType and overrode its super method getAttribute() to check the ID class for the attribute before deferring to its superclass. @Override public Attribute<? super X, ?> getAttribute(String name) { if( this.idClassAttributes != null ) { Attribute<? super X, ?> attribute = null; Iterator<SingularAttribute<? super X, ?>> i = this.idClassAttributes.iterator( ); while( i.hasNext( ) ) { attribute = i.next( ); if( attribute.getName( ).equals( name ) ) return attribute; } } return super.getAttribute( name ); } I didn't test this with EmbeddedId - that may work as is or it may need a case of its own. This is the first time I've submitted anything here, so I apologize if it is not to form.