New feature: REPLACE_PERSISTENT_COLLECTIONS to fix #93

hibernate3/src/main/java/com/fasterxml/jackson/datatype/hibernate3/Hibernate3Module.java

@@ -44,6 +44,16 @@ public enum Feature {
         * @since 2.4
         */
        REQUIRE_EXPLICIT_LAZY_LOADING_MARKER(false),
+
+        /**
+         * Replaces org.hibernate.collection.spi.PersistentCollection List, Set, Map subclasses to java.util.ArrayList, HashSet,
+         * HashMap, during Serialization.
+         * <p>
+         * Default is false.
+         *
+         * @since 2.8.2
+         */
+        REPLACE_PERSISTENT_COLLECTIONS(false)
         ;
 
         final boolean _defaultState;

hibernate3/src/main/java/com/fasterxml/jackson/datatype/hibernate3/PersistentCollectionSerializer.java

@@ -1,8 +1,13 @@
 package com.fasterxml.jackson.datatype.hibernate3;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 import javax.persistence.*;
 
@@ -21,6 +26,7 @@
 import org.hibernate.engine.SessionFactoryImplementor;
 import org.hibernate.engine.SessionImplementor;
 import org.hibernate.impl.SessionFactoryImpl;
+import org.hibernate.mapping.Bag;
 import org.hibernate.transaction.JDBCTransactionFactory;
 import org.hibernate.transaction.TransactionFactory;
 
@@ -256,6 +262,11 @@ public void serialize(Object value, JsonGenerator jgen, SerializerProvider provi
         if (_serializer == null) { // sanity check...
             throw JsonMappingException.from(jgen, "PersistentCollection does not have serializer set");
         }
+
+        if (Feature.REPLACE_PERSISTENT_COLLECTIONS.enabledIn(_features)) {
+            value = convertToJavaCollection(value); // Strip PersistentCollection
+        }
+
         _serializer.serialize(value, jgen, provider);
     }
 
@@ -279,6 +290,11 @@ public void serializeWithType(Object value, JsonGenerator jgen, SerializerProvid
         if (_serializer == null) { // sanity check...
             throw JsonMappingException.from(jgen, "PersistentCollection does not have serializer set");
         }
+
+        if (Feature.REPLACE_PERSISTENT_COLLECTIONS.enabledIn(_features)) {
+            value = convertToJavaCollection(value); // Strip PersistentCollection
+        }
+
         _serializer.serializeWithType(value, jgen, provider, typeSer);
     }
 
@@ -384,4 +400,38 @@ protected boolean usesLazyLoading(BeanProperty property)
         }
         return false;
     }
+
+    private Object convertToJavaCollection(Object value) {
+        if (!(value instanceof PersistentCollection)) {
+            return value;
+        }
+
+        if (value instanceof Set) {
+            return convertToSet((Set<?>) value);
+        }
+
+        if (value instanceof List
+                || value instanceof Bag
+                ) {
+            return convertToList((List<?>) value);
+        }
+
+        if (value instanceof Map) {
+            return convertToMap((Map<?, ?>) value);
+        }
+
+        throw new IllegalArgumentException("Unsupported type: " + value.getClass());
+    }
+
+    private Object convertToList(List<?> value) {
+        return new ArrayList<>(value);
+    }
+
+    private Object convertToMap(Map<?, ?> value) {
+        return new HashMap<>(value);
+    }
+
+    private Object convertToSet(Set<?> value) {
+        return new HashSet<>(value);
+    }
 }

hibernate3/src/test/java/com/fasterxml/jackson/datatype/hibernate3/ReplacePersistentCollectionTest.java

@@ -0,0 +1,115 @@
+package com.fasterxml.jackson.datatype.hibernate3;
+
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.datatype.hibernate3.data.Customer;
+import com.fasterxml.jackson.datatype.hibernate3.data.Payment;
+import org.hibernate.Hibernate;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+import java.util.Map;
+import java.util.Set;
+
+public class ReplacePersistentCollectionTest {
+
+	private EntityManagerFactory emf;
+
+	private EntityManager em;
+
+	@Before
+	public void setUp() throws Exception {
+		emf = Persistence.createEntityManagerFactory("persistenceUnit");
+		em = emf.createEntityManager();
+	}
+
+	@After
+	public void tearDown() throws Exception {
+		em.close();
+		emf.close();
+	}
+
+	// [Issue#93], backwards compatible case
+	@Test
+	public void testNoReplacePersistentCollection() throws Exception {
+		final ObjectMapper mapper = new ObjectMapper()
+				.registerModule(new Hibernate3Module()
+						.configure(Hibernate3Module.Feature.FORCE_LAZY_LOADING, true)
+				).enableDefaultTyping();
+
+		Customer customer = em.find(Customer.class, 103);
+		Assert.assertFalse(Hibernate.isInitialized(customer.getPayments()));
+		String json = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(customer);
+		Assert.assertTrue(json.contains("org.hibernate.collection"));
+		// should force loading...
+		Set<Payment> payments = customer.getPayments();
+                        /*
+                        System.out.println("--- JSON ---");
+                        System.out.println(json);
+                        System.out.println("--- /JSON ---");
+                        */
+
+		Assert.assertTrue(Hibernate.isInitialized(payments));
+		// TODO: verify
+		Assert.assertNotNull(json);
+
+		boolean exceptionThrown = false;
+		try {
+			Map<?, ?> stuff = mapper.readValue(json, Map.class);
+		} catch (JsonMappingException e) {
+			exceptionThrown = true;
+		}
+		Assert.assertTrue(exceptionThrown);
+	}
+
+	// [Issue#93], backwards compatible case
+	@Test
+	public void testReplacePersistentCollection() throws Exception {
+		final ObjectMapper mapper = new ObjectMapper()
+				.registerModule(new Hibernate3Module()
+						.configure(Hibernate3Module.Feature.FORCE_LAZY_LOADING, true)
+						.configure(Hibernate3Module.Feature.REPLACE_PERSISTENT_COLLECTIONS, true)
+				).enableDefaultTyping();
+
+		Customer customer = em.find(Customer.class, 103);
+		Assert.assertFalse(Hibernate.isInitialized(customer.getPayments()));
+		String json = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(customer);
+		Assert.assertFalse(json.contains("org.hibernate.collection"));
+		// should force loading...
+		Set<Payment> payments = customer.getPayments();
+        /*
+        System.out.println("--- JSON ---");
+        System.out.println(json);
+        System.out.println("--- /JSON ---");
+        */
+
+		Assert.assertTrue(Hibernate.isInitialized(payments));
+		// TODO: verify
+		Assert.assertNotNull(json);
+
+        /*
+         * Currently this cannot be verified due to Issue#94 default typing fails on 2.7.0 - 2.8.2-SNAPSHOT,
+         * commented out until that is fixed.
+         */
+
+		boolean issue94failed = false;
+		try {
+			Map<?, ?> stuff = mapper.readValue(json, Map.class);
+		} catch (JsonMappingException e) {
+			issue94failed = true;
+		}
+
+		Assert.assertTrue("If this fails, means #94 is fixed. Replace to the below commented lines", issue94failed);
+
+//		Map<?, ?> stuff = mapper.readValue(json, Map.class);
+//
+//		Assert.assertTrue(stuff.containsKey("payments"));
+//		Assert.assertTrue(stuff.containsKey("orders"));
+//		Assert.assertNull(stuff.get("orderes"));
+	}
+}

hibernate4/src/main/java/com/fasterxml/jackson/datatype/hibernate4/Hibernate4Module.java

@@ -54,6 +54,16 @@ public enum Feature {
          * @since 2.4
          */
         REQUIRE_EXPLICIT_LAZY_LOADING_MARKER(false),
+
+        /**
+         * Replaces org.hibernate.collection.spi.PersistentCollection List, Set, Map subclasses to java.util.ArrayList, HashSet,
+         * HashMap, during Serialization.
+         * <p>
+         * Default is false.
+         *
+         * @since 2.8.2
+         */
+        REPLACE_PERSISTENT_COLLECTIONS(false)
         ;
 
         final boolean _defaultState;

hibernate4/src/main/java/com/fasterxml/jackson/datatype/hibernate4/PersistentCollectionSerializer.java

@@ -18,12 +18,18 @@
 import org.hibernate.engine.spi.PersistenceContext;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.SessionImplementor;
+import org.hibernate.mapping.Bag;
 
 import javax.persistence.*;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * Wrapper serializer used to handle aspects of lazy loading that can be used
@@ -250,6 +256,11 @@ public void serialize(Object value, JsonGenerator jgen, SerializerProvider provi
         if (_serializer == null) { // sanity check...
             throw JsonMappingException.from(jgen, "PersistentCollection does not have serializer set");
         }
+
+        if (Feature.REPLACE_PERSISTENT_COLLECTIONS.enabledIn(_features)) {
+            value = convertToJavaCollection(value); // Strip PersistentCollection
+        }
+
         _serializer.serialize(value, jgen, provider);
     }
 
@@ -268,6 +279,11 @@ public void serializeWithType(Object value, JsonGenerator jgen, SerializerProvid
         if (_serializer == null) { // sanity check...
             throw JsonMappingException.from(jgen, "PersistentCollection does not have serializer set");
         }
+
+        if (Feature.REPLACE_PERSISTENT_COLLECTIONS.enabledIn(_features)) {
+            value = convertToJavaCollection(value); // Strip PersistentCollection
+        }
+
         _serializer.serializeWithType(value, jgen, provider, typeSer);
     }
 
@@ -368,4 +384,38 @@ protected boolean usesLazyLoading(BeanProperty property) {
         }
         return false;
     }
+
+    private Object convertToJavaCollection(Object value) {
+        if (!(value instanceof PersistentCollection)) {
+            return value;
+        }
+
+        if (value instanceof Set) {
+            return convertToSet((Set<?>) value);
+        }
+
+        if (value instanceof List
+                || value instanceof Bag
+                ) {
+            return convertToList((List<?>) value);
+        }
+
+        if (value instanceof Map) {
+            return convertToMap((Map<?, ?>) value);
+        }
+
+        throw new IllegalArgumentException("Unsupported type: " + value.getClass());
+    }
+
+    private Object convertToList(List<?> value) {
+        return new ArrayList<>(value);
+    }
+
+    private Object convertToMap(Map<?, ?> value) {
+        return new HashMap<>(value);
+    }
+
+    private Object convertToSet(Set<?> value) {
+        return new HashSet<>(value);
+    }
 }