内部带有集合的实体视图不使用 Blaze 持久性

Question

我对使用 blaze 持久性库的实体视图有疑问。我想检索供应商列表，每个供应商都有一个产品列表，但我在创建实体视图模型时遇到异常。

设置

Blaze 持久性核心 1.6.6
Blaze 持久性实体视图 1.6.6
Spring 数据 JPA 2.5.6
休眠 5.4.27

我正在使用显示的 Blaze 基本配置 here。

型号

这是我的模型（为了更清楚，我删除了一些字段）：

@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;
}

实体浏览量

@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();
}

例外情况

我在启动时遇到的异常如下：

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

我尝试通过调试和调查库代码来进行一些测试，我发现如果我将 @MappingIndex 添加到视图中的产品列表中，抛出的异常似乎更清楚。我还没有完全理解映射索引是如何工作的，但也许它是相关的。以下是新的异常：

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

有人知道如何解决我的问题吗？

提前致谢！

Answer 1

我现在测试了您的示例应用程序，我看到了这个异常：

Caused by: java.lang.IllegalArgumentException: Illegal occurence of [products] in path chain resolver!
    at com.blazebit.persistence.parser.PathTargetResolvingExpressionVisitor.invalid(PathTargetResolvingExpressionVisitor.java:562)
    at com.blazebit.persistence.parser.PathTargetResolvingExpressionVisitor.visit(PathTargetResolvingExpressionVisitor.java:468)
    at com.blazebit.persistence.parser.expression.EntityLiteral.accept(EntityLiteral.java:50)
    at com.blazebit.persistence.view.impl.metamodel.MetamodelUtils.isIndexedList(MetamodelUtils.java:125)
    at com.blazebit.persistence.view.impl.metamodel.MetamodelUtils.isIndexedList(MetamodelUtils.java:120)
    at com.blazebit.persistence.view.impl.metamodel.AttributeMapping.determineIndexed(AttributeMapping.java:333)
    at com.blazebit.persistence.view.impl.metamodel.attribute.AbstractMethodListAttribute.<init>(AbstractMethodListAttribute.java:61)
    at com.blazebit.persistence.view.impl.metamodel.attribute.MappingMethodListAttribute.<init>(MappingMethodListAttribute.java:35)
    at com.blazebit.persistence.view.impl.metamodel.MethodAttributeMapping.getMethodAttribute(MethodAttributeMapping.java:757)
    at com.blazebit.persistence.view.impl.metamodel.ManagedViewTypeImpl.<init>(ManagedViewTypeImpl.java:319)
    at com.blazebit.persistence.view.impl.metamodel.FlatViewTypeImpl.<init>(FlatViewTypeImpl.java:41)
    at com.blazebit.persistence.view.impl.metamodel.ViewMappingImpl.getManagedViewType(ViewMappingImpl.java:892)
    at com.blazebit.persistence.view.impl.metamodel.MetamodelBuildingContextImpl.getManagedViewType(MetamodelBuildingContextImpl.java:234)
    at com.blazebit.persistence.view.impl.metamodel.ViewMetamodelImpl.<init>(ViewMetamodelImpl.java:88)
    at com.blazebit.persistence.view.impl.EntityViewManagerImpl.<init>(EntityViewManagerImpl.java:271)

错误意味着在幕后为 SupplierWithProductsView#getProducts 创建的表达式 products 是非法的。这是关联被命名为与实体 ProductEntity 相同的不幸副作用，即 @Entity(name = "products")。我为此创建了以下错误报告，并将尽快对此进行调查：https://github.com/Blazebit/blaze-persistence/issues/1450

同时，您可以将关联重命名为例如productList、seelingProducts 或类似的东西。或者，您也可以使用 @Entity(name = "product") 重命名实体，即省略 s.

内部带有集合的实体视图不使用 Blaze 持久性

Entity view with a collection inside not working with Blaze persistance

java

blaze-persistence

设置

型号

实体浏览量

例外情况