HHH-12238 - aliasToBean throws confusing ClassCastException if class lacks setters

hibernate-core/src/main/java/org/hibernate/property/access/internal/PropertyAccessStrategyMapImpl.java

@@ -6,6 +6,7 @@
  */
 package org.hibernate.property.access.internal;
 
+import org.hibernate.mapping.Map;
 import org.hibernate.property.access.spi.PropertyAccess;
 import org.hibernate.property.access.spi.PropertyAccessStrategy;
 
@@ -21,6 +22,19 @@ public class PropertyAccessStrategyMapImpl implements PropertyAccessStrategy {
 
 	@Override
 	public PropertyAccess buildPropertyAccess(Class containerJavaType, String propertyName) {
+		
+		// Sometimes containerJavaType is null, but if it isn't, make sure it's a Map.
+		if (containerJavaType != null && !Map.class.isAssignableFrom(containerJavaType)) {
+			throw new IllegalArgumentException(
+				String.format(
+					"Expecting class: [%1$s], but containerJavaType is of type: [%2$s] for propertyName: [%3$s]",
+					Map.class.getName(),
+					containerJavaType.getName(),
+					propertyName
+				)
+			);
+		}
+
 		return new PropertyAccessMapImpl( this, propertyName );
 	}
 }

hibernate-core/src/test/java/org/hibernate/property/PropertyAccessStrategyMapTest.java

@@ -0,0 +1,65 @@
+/*
+ * 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.property;
+
+import java.util.Date;
+import java.util.HashMap;
+
+import org.hibernate.mapping.Map;
+import org.hibernate.property.access.internal.PropertyAccessStrategyMapImpl;
+import org.hibernate.property.access.spi.PropertyAccess;
+
+import org.hibernate.testing.junit4.BaseUnitTestCase;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+public class PropertyAccessStrategyMapTest extends BaseUnitTestCase {
+
+	@Test
+	public void testBasicMapClass() {
+		testBasic( Map.class );
+	}
+
+	@Test
+	public void testBasicNullClass() {
+		testBasic( null );
+	}
+
+	@Test
+	public void testNonMap() {
+		final PropertyAccessStrategyMapImpl accessStrategy = PropertyAccessStrategyMapImpl.INSTANCE;
+
+		try {
+			accessStrategy.buildPropertyAccess( Date.class, "time" );
+
+			fail("Should throw IllegalArgumentException");
+		}
+		catch (IllegalArgumentException e) {
+			assertEquals(
+				"Expecting class: [org.hibernate.mapping.Map], but containerJavaType is of type: [java.util.Date] for propertyName: [time]",
+				e.getMessage()
+			);
+		}
+	}
+
+	private void testBasic(final Class<?> clazz) {
+
+		final String key = "testKey";
+		final String value = "testValue";
+
+		final PropertyAccessStrategyMapImpl accessStrategy = PropertyAccessStrategyMapImpl.INSTANCE;
+		final PropertyAccess access = accessStrategy.buildPropertyAccess( clazz, key );
+
+		final HashMap<String, String> map = new HashMap<>();
+
+		access.getSetter().set( map, value, null );
+		assertEquals( value, map.get( key ) );
+		assertEquals( value, access.getGetter().get( map ) );
+	}
+}