I have a problem with entity views using blaze persistence library. I want to retrieve a list of Suppliers, each one with a list of Products but I'm getting an exception while creating Entity views model.
Setup
- Blaze persistence core 1.6.6
- Blaze persistence Entity View 1.6.6
- Spring Data JPA 2.5.6
- Hibernate 5.4.27
I'm using Blaze base configuration shown here.
Model
This is my model (I have removed some fields to be more clear):
@Entity(name = "suppliers")
public class Supplier extends BaseEntity {
@Column(nullable = false, length = 100)
private String businessName;
@OneToMany(mappedBy = "supplier")
private List<Product> products;
}
@Entity(name = "products")
public class Product extends BaseEntity {
@Column(nullable = false)
private String name;
@Column(nullable = false)
private Integer price;
@ManyToOne
private Supplier supplier;
}
Entity views
@EntityView(Supplier.class)
public interface SupplierWithProductsView {
Integer getId();
String getBusinessName();
List<ProductView> getProducts();
}
@EntityView(Product.class)
public interface ProductView {
Integer getId();
String getName();
Integer getPrice();
}
Exceptions
The exception I get at startup is the following:
Caused by: java.lang.IllegalArgumentException: Illegal occurence of [products] in path chain resolver!
at com.blazebit.persistence.parser.PathTargetResolvingExpressionVisitor.invalid(PathTargetResolvingExpressionVisitor.java:562) ~[blaze-persistence-core-parser-1.6.6.jar:1.6.6]
at com.blazebit.persistence.parser.PathTargetResolvingExpressionVisitor.visit(PathTargetResolvingExpressionVisitor.java:468) ~[blaze-persistence-core-parser-1.6.6.jar:1.6.6]
at com.blazebit.persistence.parser.expression.EntityLiteral.accept(EntityLiteral.java:50) ~[blaze-persistence-core-parser-1.6.6.jar:1.6.6]
at com.blazebit.persistence.view.impl.metamodel.MetamodelUtils.isIndexedList(MetamodelUtils.java:125) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
at com.blazebit.persistence.view.impl.metamodel.MetamodelUtils.isIndexedList(MetamodelUtils.java:120) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
at com.blazebit.persistence.view.impl.metamodel.AttributeMapping.determineIndexed(AttributeMapping.java:333) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
at com.blazebit.persistence.view.impl.metamodel.attribute.AbstractMethodListAttribute.<init>(AbstractMethodListAttribute.java:61) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
at com.blazebit.persistence.view.impl.metamodel.attribute.MappingMethodListAttribute.<init>(MappingMethodListAttribute.java:35) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
at com.blazebit.persistence.view.impl.metamodel.MethodAttributeMapping.getMethodAttribute(MethodAttributeMapping.java:757) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
at com.blazebit.persistence.view.impl.metamodel.ManagedViewTypeImpl.<init>(ManagedViewTypeImpl.java:319) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
at com.blazebit.persistence.view.impl.metamodel.FlatViewTypeImpl.<init>(FlatViewTypeImpl.java:41) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
at com.blazebit.persistence.view.impl.metamodel.ViewMappingImpl.getManagedViewType(ViewMappingImpl.java:892) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
at com.blazebit.persistence.view.impl.metamodel.MetamodelBuildingContextImpl.getManagedViewType(MetamodelBuildingContextImpl.java:234) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
at com.blazebit.persistence.view.impl.metamodel.ViewMetamodelImpl.<init>(ViewMetamodelImpl.java:88) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
at com.blazebit.persistence.view.impl.EntityViewManagerImpl.<init>(EntityViewManagerImpl.java:271) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
... 60 common frames omitted
I tried to take some tests by debugging and investigating in the library code and I found that if I add @MappingIndex to the products list in the view, the exception thrown seems more clear. I haven't fully understood how the mapping index works but maybe it is correlated. The following is the new exception:
Caused by: java.lang.IllegalArgumentException: There are error(s) in entity views!
The resolved possible types [java.util.List] are not assignable to the given expression type 'java.util.Collection<my.package.Product>' of the mapping expression declared by the attribute products[my.package.SupplierWithProductsView.getProducts]!
at com.blazebit.persistence.view.impl.EntityViewManagerImpl.<init>(EntityViewManagerImpl.java:285) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
at com.blazebit.persistence.view.impl.EntityViewConfigurationImpl.createEntityViewManager(EntityViewConfigurationImpl.java:206) ~[blaze-persistence-entity-view-impl-1.6.6.jar:1.6.6]
at my.package.configurations.BlazePersistenceConfig.createEntityViewManager(BlazePersistenceConfig.java:44) ~[main/:na]
... other lines omitted
Anyone has any idea how to solve my problem?
Thanks in advance!
