HHH-12945 Properly support entry() criteria expression

With additional changes from Gail.

hibernate-core/src/main/java/org/hibernate/query/criteria/internal/expression/MapEntryExpression.java

@@ -7,15 +7,17 @@
 package org.hibernate.query.criteria.internal.expression;
 
 import java.io.Serializable;
+import java.util.Arrays;
+import java.util.List;
 import java.util.Map;
-import javax.persistence.criteria.Expression;
+
-import javax.persistence.metamodel.MapAttribute;
+import javax.persistence.criteria.CompoundSelection;
+import javax.persistence.criteria.Selection;
 
 import org.hibernate.query.criteria.internal.CriteriaBuilderImpl;
 import org.hibernate.query.criteria.internal.ParameterRegistry;
-import org.hibernate.query.criteria.internal.PathImplementor;
-import org.hibernate.query.criteria.internal.Renderable;
 import org.hibernate.query.criteria.internal.compile.RenderingContext;
+import org.hibernate.query.criteria.internal.path.MapAttributeJoin;
 import org.hibernate.sql.ast.Clause;
 
 /**
@@ -25,41 +27,41 @@ import org.hibernate.sql.ast.Clause;
  */
 public class MapEntryExpression<K,V>
 		extends ExpressionImpl<Map.Entry<K,V>>
-		implements Expression<Map.Entry<K,V>>, Serializable {
+		implements CompoundSelection<Map.Entry<K,V>>, Serializable {
 
-	private final PathImplementor origin;
+	private final MapAttributeJoin<?, K, V> original;
-	private final MapAttribute<?, K, V> attribute;
 
 	public MapEntryExpression(
 			CriteriaBuilderImpl criteriaBuilder,
 			Class<Map.Entry<K, V>> javaType,
-			PathImplementor origin,
+			MapAttributeJoin<?, K, V> original) {
-			MapAttribute<?, K, V> attribute) {
+		super( criteriaBuilder, javaType );
-		super( criteriaBuilder, javaType);
+		this.original = original;
-		this.origin = origin;
-		this.attribute = attribute;
-	}
-
-	public MapAttribute<?, K, V> getAttribute() {
-		return attribute;
 	}
 
+	@Override
 	public void registerParameters(ParameterRegistry registry) {
 		// none to register
 	}
 
+	@Override
 	public String render(RenderingContext renderingContext) {
 		if ( renderingContext.getClauseStack().getCurrent() == Clause.SELECT ) {
-			return "entry(" + path( renderingContext ) + ")";
+			return "entry(" + original.render( renderingContext ) + ")";
 		}
 
 		// don't think this is valid outside of select clause...
 		throw new IllegalStateException( "illegal reference to map entry outside of select clause." );
 	}
 
-	private String path(RenderingContext renderingContext) {
+	@Override
-		return origin.getPathIdentifier()
+	public boolean isCompoundSelection() {
-				+ '.'
+		return true;
-				+ ( (Renderable) getAttribute() ).render( renderingContext );
 	}
+
+	@Override
+	public List<Selection<?>> getCompoundSelectionItems() {
+		return Arrays.asList( original.key(), original.value() );
+	}
+
 }

hibernate-core/src/main/java/org/hibernate/query/criteria/internal/path/MapAttributeJoin.java

@@ -77,7 +77,7 @@ public class MapAttributeJoin<O,K,V>
 	@Override
 	@SuppressWarnings({ "unchecked" })
 	public Expression<Map.Entry<K, V>> entry() {
-		return new MapEntryExpression( criteriaBuilder(), Map.Entry.class, this, getAttribute() );
+		return new MapEntryExpression( criteriaBuilder(), Map.Entry.class, this );
 	}
 
 	@Override

hibernate-core/src/test/java/org/hibernate/jpa/test/criteria/mapjoin/Customer.java

@@ -0,0 +1,70 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.jpa.test.criteria.mapjoin;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.OneToMany;
+
+@Entity
+public class Customer {
+
+	@Id
+	@GeneratedValue
+	private int id;
+	private String name;
+	@OneToMany(cascade = CascadeType.ALL)
+	private Map<String, CustomerOrder> orderMap;
+
+	public int getId() {
+		return id;
+	}
+
+	public void setId(int id) {
+		this.id = id;
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	public Map<String, CustomerOrder> getOrderMap() {
+		return orderMap;
+	}
+
+	public void setOrderMap(Map<String, CustomerOrder> orderMap) {
+		this.orderMap = orderMap;
+	}
+
+	public void addOrder(String orderType, String itemName, int qty) {
+		if ( orderMap == null ) {
+			orderMap = new HashMap<>();
+		}
+		CustomerOrder order = new CustomerOrder();
+		order.setItem( itemName );
+		order.setQty( qty );
+		orderMap.put( orderType, order );
+	}
+
+	@Override
+	public String toString() {
+		return "Customer{" +
+				"id=" + id +
+				", name='" + name + '\'' +
+				", orderMap=" + orderMap +
+				'}';
+	}
+}

hibernate-core/src/test/java/org/hibernate/jpa/test/criteria/mapjoin/CustomerOrder.java

@@ -0,0 +1,46 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.jpa.test.criteria.mapjoin;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+@Entity
+public class CustomerOrder {
+
+	@Id
+	@GeneratedValue
+	private long id;
+	private String item;
+	private int qty;
+
+	public String getItem() {
+		return item;
+	}
+
+	public void setItem(String item) {
+		this.item = item;
+	}
+
+	public int getQty() {
+		return qty;
+	}
+
+	public void setQty(int qty) {
+		this.qty = qty;
+	}
+
+	@Override
+	public String toString() {
+		return "Order{" +
+				"id=" + id +
+				", item='" + item + '\'' +
+				", qty=" + qty +
+				'}';
+	}
+}

hibernate-core/src/test/java/org/hibernate/jpa/test/criteria/mapjoin/MapJoinEntryTest.java

@@ -0,0 +1,77 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.jpa.test.criteria.mapjoin;
+
+import static org.hibernate.testing.transaction.TransactionUtil.doInJPA;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.util.List;
+import java.util.Map;
+
+import javax.persistence.TypedQuery;
+import javax.persistence.criteria.CriteriaBuilder;
+import javax.persistence.criteria.CriteriaQuery;
+import javax.persistence.criteria.MapJoin;
+import javax.persistence.criteria.Root;
+
+import org.hibernate.jpa.test.BaseEntityManagerFunctionalTestCase;
+import org.hibernate.testing.TestForIssue;
+import org.junit.Before;
+import org.junit.Test;
+
+public class MapJoinEntryTest extends BaseEntityManagerFunctionalTestCase {
+
+	@Override
+	public Class[] getAnnotatedClasses() {
+		return new Class[]{ Customer.class, CustomerOrder.class };
+	}
+
+	@Before
+	public void setup() {
+		doInJPA( this::entityManagerFactory, em -> {
+			Customer customer = new Customer();
+			customer.setName( "Morgan Philips" );
+			customer.addOrder( "online", "AA Glass Cleaner", 3 );
+
+			em.persist( customer );
+		} );
+	}
+
+	@Test
+	@TestForIssue(jiraKey = "HHH-12945")
+	public void testMapJoinEntryCriteria() {
+		doInJPA( this::entityManagerFactory, em -> {
+			CriteriaBuilder criteriaBuilder = em.getCriteriaBuilder();
+
+			CriteriaQuery<Map.Entry> query = criteriaBuilder.createQuery( Map.Entry.class );
+			Root<Customer> customer = query.from( Customer.class );
+			MapJoin<Customer, String, CustomerOrder> orderMap = customer.join( Customer_.orderMap );
+			query.select( orderMap.entry() );
+
+			TypedQuery<Map.Entry> typedQuery = em.createQuery( query );
+			List<Map.Entry> resultList = typedQuery.getResultList();
+
+			assertEquals( 1, resultList.size() );
+			assertEquals( "online", resultList.get( 0 ).getKey() );
+			assertEquals( "AA Glass Cleaner", ( (CustomerOrder) resultList.get( 0 ).getValue() ).getItem() );
+		} );
+	}
+
+	@Test
+	public void testMapJoinEntryJPQL() {
+		doInJPA( this::entityManagerFactory, em -> {
+			TypedQuery<Map.Entry> query = em.createQuery( "SELECT ENTRY(mp) FROM Customer c JOIN c.orderMap mp",
+					Map.Entry.class );
+			List<Map.Entry> resultList = query.getResultList();
+
+			assertEquals( 1, resultList.size() );
+			assertEquals( "online", resultList.get( 0 ).getKey() );
+			assertEquals( "AA Glass Cleaner", ( (CustomerOrder) resultList.get( 0 ).getValue() ).getItem() );
+		} );
+	}
+}