Handle ORM proxy subclass comparison in Entity and ValueObject support classes.

dddsample/tracking/core/src/main/java/se/citerus/dddsample/tracking/core/domain/patterns/OrmUtils.java

@@ -0,0 +1,36 @@
+package se.citerus.dddsample.tracking.core.domain.patterns;
+
+import org.hibernate.proxy.AbstractLazyInitializer;
+import org.hibernate.proxy.HibernateProxy;
+
+import java.lang.reflect.Field;
+
+/**
+ * Utils for working with (around) the ORM framework, i.e. Hibernate.
+ */
+public class OrmUtils {
+
+  private static final String HANDLER_FIELD_NAME = "handler";
+
+  /**
+   * @param o an object, possibly wrapped in a lazy proxy
+   * @return the wrapped persistent entity (if wrapped), or o
+   */
+  public static Object unwrapOrmProxy(final Object o) {
+    if (o instanceof HibernateProxy) {
+      try {
+        final Field handlerField = o.getClass().getDeclaredField(HANDLER_FIELD_NAME);
+        handlerField.setAccessible(true);
+        final AbstractLazyInitializer handler = (AbstractLazyInitializer) handlerField.get(o);
+        return handler.getImplementation();
+      } catch (IllegalAccessException e) {
+        throw new AssertionError(e);
+      } catch (NoSuchFieldException e) {
+        throw new AssertionError(e);
+      }
+    } else {
+      return o;
+    }
+  }
+
+}

dddsample/tracking/core/src/main/java/se/citerus/dddsample/tracking/core/domain/patterns/entity/EntitySupport.java

@@ -1,12 +1,14 @@
 package se.citerus.dddsample.tracking.core.domain.patterns.entity;
 
+import static se.citerus.dddsample.tracking.core.domain.patterns.OrmUtils.unwrapOrmProxy;
+
 /**
  * Supporting base class for entities.
  *
  * While the Entity interface makes the pattern properties explicit,
  * this class is less general and is suited for this particular application.
  * </p>
- * For example, the private id field is meant for autogenerated, surrogate primary keys.
+ * For example, the private _primaryKey field is meant for autogenerated, numerical surrogate primary keys.
  */
 public abstract class EntitySupport<T extends Entity, ID> implements Entity<T, ID> {
 
@@ -23,15 +25,14 @@ public abstract class EntitySupport<T extends Entity, ID> implements Entity<T, I
     return identity().hashCode();
   }
 
-  @SuppressWarnings({"SimplifiableIfStatement", "unchecked"})
+  @SuppressWarnings({"SimplifiableIfStatement", "unchecked", "EqualsWhichDoesntCheckParameterClass"})
   @Override
-  public final boolean equals(final Object o) {
-    if (this == o) return true;
-    // TODO class comparision is too strict for ORM proxies
-    if (o == null || !(o instanceof EntitySupport)) return false;
-    //if (o == null || getClass() != o.getClass()) return false;
+  public final boolean equals(final Object other) {
+    if (other == null) return false;
+    if (this == other) return true;
+    if (unwrapOrmProxy(this).getClass() != unwrapOrmProxy(other).getClass()) return false;
 
-    return sameAs((T) o);
+    return sameAs((T) other);
   }
 
 }

dddsample/tracking/core/src/main/java/se/citerus/dddsample/tracking/core/domain/patterns/valueobject/ValueObjectSupport.java

@@ -2,10 +2,11 @@ package se.citerus.dddsample.tracking.core.domain.patterns.valueobject;
 
 import org.apache.commons.lang.builder.EqualsBuilder;
 import org.apache.commons.lang.builder.HashCodeBuilder;
+import static se.citerus.dddsample.tracking.core.domain.patterns.OrmUtils.unwrapOrmProxy;
 
 /**
  * Supporting base class for value objects.
- *
+ * <p/>
  * While the ValueObject interface makes the pattern properties explicit,
  * this class is less general and is suited for this particular application.
  * </p>
@@ -21,7 +22,7 @@ public abstract class ValueObjectSupport<T extends ValueObject> implements Value
   @SuppressWarnings("UnusedDeclaration")
   private final Long _primaryKey = null;
   private transient int _cachedHashCode = 0;
-  private final static String[] EXCLUDED_FIELDS = {"_primaryKey", "_cachedHashCode"};
+  private static final String[] EXCLUDED_FIELDS = {"_primaryKey", "_cachedHashCode"};
 
   /**
    * @param other The other value object.
@@ -29,7 +30,7 @@ public abstract class ValueObjectSupport<T extends ValueObject> implements Value
    */
   @Override
   public final boolean sameValueAs(final T other) {
-    return other != null && EqualsBuilder.reflectionEquals(this, other, EXCLUDED_FIELDS);
+    return other != null && EqualsBuilder.reflectionEquals(unwrapOrmProxy(this), unwrapOrmProxy(other), EXCLUDED_FIELDS);
   }
 
   /**
@@ -56,16 +57,17 @@ public abstract class ValueObjectSupport<T extends ValueObject> implements Value
   }
 
   /**
-   * @param o other object
+   * @param other other object
    * @return True if other object has the same value as this value object.
    */
-  @SuppressWarnings({"SimplifiableIfStatement", "unchecked"})
+  @SuppressWarnings({"SimplifiableIfStatement", "unchecked", "EqualsWhichDoesntCheckParameterClass"})
   @Override
-  public final boolean equals(final Object o) {
-    if (this == o) return true;
-    if (o == null || getClass() != o.getClass()) return false;
+  public final boolean equals(final Object other) {
+    if (other == null) return false;
+    if (this == other) return true;
+    if (unwrapOrmProxy(this).getClass() != unwrapOrmProxy(other).getClass()) return false;
 
-    return sameValueAs((T) o);
+    return sameValueAs((T) other);
   }
 
 }