Fix #44 for 2.2.x branch

Author: cowtowncoder

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

@@ -7,7 +7,6 @@
 import org.hibernate.collection.PersistentCollection;
 
 import com.fasterxml.jackson.core.*;
-
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.databind.jsontype.TypeSerializer;
 import com.fasterxml.jackson.databind.ser.*;
@@ -56,14 +55,18 @@ public JsonSerializer<?> createContextual(SerializerProvider provider,
             BeanProperty property)
         throws JsonMappingException
     {
+        JsonSerializer<?> ser = _serializer;
+        if (ser instanceof ContextualSerializer) {
+            ser = ((ContextualSerializer) ser).createContextual(provider, property);
+        }
         // If we use eager loading, or force it, can just return underlying serializer as is
         if (_forceLazyLoading || !usesLazyLoading(property)) {
-            if (_serializer instanceof ContextualSerializer) {
-                return ((ContextualSerializer) _serializer).createContextual(provider, property);
-            }
-            return _serializer;
+            return ser;
         }
         // Otherwise this instance is to be used
+        if (ser != _serializer) {
+            return new PersistentCollectionSerializer(_forceLazyLoading, ser);
+        }
         return this;
     }
 

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

@@ -0,0 +1,45 @@
+package com.fasterxml.jackson.datatype.hibernate3;
+
+import java.util.*;
+
+import javax.persistence.OneToMany;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+public class OneToManyTest extends BaseTest
+{
+    static final String EXPECTED_JSON = "{\"m\":{\"A\":\"A\"}}";
+
+    static final class X {
+        @OneToMany
+        public final Map<String, String> m = new LinkedHashMap<String, String>();
+    }
+    
+    static final class Y {
+        public final Map<String, String> m = new LinkedHashMap<String, String>();
+    }
+    
+    public void testMap() throws Exception {
+        Y object = new Y();
+        object.m.put("A", "A");
+    
+        assertEquals(EXPECTED_JSON, mapWithoutHibernateModule(object));
+        assertEquals(EXPECTED_JSON, mapWithHibernateModule(object));
+    }
+    
+    public void testMapWithOneToMany() throws Exception {
+        X object = new X();
+        object.m.put("A", "A");
+    
+        assertEquals(EXPECTED_JSON, mapWithoutHibernateModule(object));
+        assertEquals(EXPECTED_JSON, mapWithHibernateModule(object));
+    }
+    
+    private String mapWithHibernateModule(Object object) throws Exception {
+        return new ObjectMapper().registerModule(new Hibernate3Module()).writeValueAsString(object);
+    }
+    
+    private String mapWithoutHibernateModule(Object object) throws Exception {
+        return new ObjectMapper().writeValueAsString(object);
+    }
+}

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

@@ -61,14 +61,18 @@ public JsonSerializer<?> createContextual(SerializerProvider provider,
             BeanProperty property)
         throws JsonMappingException
     {
+        JsonSerializer<?> ser = _serializer;
+        if (ser instanceof ContextualSerializer) {
+            ser = ((ContextualSerializer) ser).createContextual(provider, property);
+        }
         // If we use eager loading, or force it, can just return underlying serializer as is
         if (_forceLazyLoading || !usesLazyLoading(property)) {
-            if (_serializer instanceof ContextualSerializer) {
-                return ((ContextualSerializer) _serializer).createContextual(provider, property);
-            }
-            return _serializer;
+            return ser;
         }
         // Otherwise this instance is to be used
+        if (ser != _serializer) {
+            return new PersistentCollectionSerializer(_forceLazyLoading, ser);
+        }
         return this;
     }
 

hibernate4/src/test/java/com/fasterxml/jackson/datatype/hibernate4/OneToManyTest.java

@@ -0,0 +1,45 @@
+package com.fasterxml.jackson.datatype.hibernate4;
+
+import java.util.*;
+
+import javax.persistence.OneToMany;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+public class OneToManyTest extends BaseTest
+{
+    static final String EXPECTED_JSON = "{\"m\":{\"A\":\"A\"}}";
+
+    static final class X {
+        @OneToMany
+        public final Map<String, String> m = new LinkedHashMap<String, String>();
+    }
+    
+    static final class Y {
+        public final Map<String, String> m = new LinkedHashMap<String, String>();
+    }
+    
+    public void testMap() throws Exception {
+        Y object = new Y();
+        object.m.put("A", "A");
+    
+        assertEquals(EXPECTED_JSON, mapWithoutHibernateModule(object));
+        assertEquals(EXPECTED_JSON, mapWithHibernateModule(object));
+    }
+    
+    public void testMapWithOneToMany() throws Exception {
+        X object = new X();
+        object.m.put("A", "A");
+    
+        assertEquals(EXPECTED_JSON, mapWithoutHibernateModule(object));
+        assertEquals(EXPECTED_JSON, mapWithHibernateModule(object));
+    }
+    
+    private String mapWithHibernateModule(Object object) throws Exception {
+        return new ObjectMapper().registerModule(new Hibernate4Module()).writeValueAsString(object);
+    }
+    
+    private String mapWithoutHibernateModule(Object object) throws Exception {
+        return new ObjectMapper().writeValueAsString(object);
+    }
+}

release-notes/VERSION

@@ -1,15 +1,20 @@
 Project: jackson-datatype-hibernate
 Jackson module to support datatypes of Hibernate 3.6 / 4.x, based on Jackson 2.x
 
-Version: 2.2.3 (23-Aug-2013)
+Version: 2.2.4 (xx-xxx-2013)
 
-#39: Avoid NullPointerException when serializing ManyToOne proxies
- (contributed by drvdijk@github)
+#44: NullPointerException when @OneToMany map is encountered
+ (reported by Patrick H)
 
 ------------------------------------------------------------------------
 === History: ===
 ------------------------------------------------------------------------
 
+2.2.3 (23-Aug-2013)
+
+#39: Avoid NullPointerException when serializing ManyToOne proxies
+ (contributed by drvdijk@github)
+
 2.2.2 (28-May-2013)
 2.2.1 (04-May-2013)