Fixed #41

Author: cowtowncoder

pom.xml

@@ -21,6 +21,13 @@ Guava (http://code.google.com/p/guava-libraries/) types (currently mostly just c
     <tag>HEAD</tag>
   </scm>
 
+  <contributors>
+    <contributor>
+      <name>Steven Schlansker</name>
+      <email>[email protected]</email>
+    </contributor>
+  </contributors>
+
   <properties>
     <version.jackson>2.3.2</version.jackson>
 

release-notes/VERSION

@@ -1,13 +1,18 @@
 Project: jackson-datatype-guava
-Version: 2.3.2 (01-Mar-2014)
+Version: 2.3.3 (xx-xxx-2014)
 
-#36: Improve Range deserializer to work with older Guava versions (10-)
- (contribtued by ispringer@github)
+#41: `Multimap` serializer does not honor @JsonInclude(JsonInclude.Include.NON_EMPTY) 
+ (reported by Olve S-H)
 
 ------------------------------------------------------------------------
 === History: ===
 ------------------------------------------------------------------------
 
+2.3.2 (01-Mar-2014)
+
+#36: Improve Range deserializer to work with older Guava versions (10-)
+ (contribtued by ispringer@github)
+
 2.3.1 (28-Dec-2013)
 
 #33: Add support for `Range` values

src/main/java/com/fasterxml/jackson/datatype/guava/ser/MultimapSerializer.java

@@ -8,14 +8,15 @@
 
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.databind.jsontype.TypeSerializer;
+import com.fasterxml.jackson.databind.ser.ContainerSerializer;
 import com.fasterxml.jackson.databind.ser.ContextualSerializer;
 import com.fasterxml.jackson.databind.type.MapLikeType;
 
 import com.google.common.collect.Lists;
 import com.google.common.collect.Multimap;
 
 public class MultimapSerializer
-    extends JsonSerializer<Multimap<?, ?>>
+    extends ContainerSerializer<Multimap<?, ?>>
     implements ContextualSerializer
 {
     private final MapLikeType _type;
@@ -31,6 +32,7 @@ public MultimapSerializer(SerializationConfig config,
             TypeSerializer valueTypeSerializer,
             JsonSerializer<Object> valueSerializer)
     {
+        super(type.getRawClass(), false);
         _type = type;
         _property = null;
         _keySerializer = keySerializer;
@@ -43,6 +45,7 @@ protected MultimapSerializer(MultimapSerializer src, BeanProperty property,
                 JsonSerializer<?> keySerializer,
                 TypeSerializer valueTypeSerializer, JsonSerializer<?> valueSerializer)
     {
+        super(src);
         _type = src._type;
         _property = property;
         _keySerializer = (JsonSerializer<Object>) keySerializer;
@@ -56,6 +59,12 @@ protected MultimapSerializer withResolved(BeanProperty property,
     {
         return new MultimapSerializer(this, property, keySer, vts, valueSer);
     }
+
+    @Override
+    protected ContainerSerializer<?> _withValueTypeSerializer(TypeSerializer typeSer) {
+        return new MultimapSerializer(this, _property, _keySerializer,
+                typeSer, _valueSerializer);
+    }
 
     /*
     /**********************************************************
@@ -92,7 +101,33 @@ public JsonSerializer<?> createContextual(SerializerProvider provider,
 
     /*
     /**********************************************************
-    /* JsonSerializer implementation
+    /* Accessors for ContainerSerializer
+    /**********************************************************
+     */
+    
+    @Override
+    public JsonSerializer<?> getContentSerializer() {
+        return _valueSerializer;
+    }
+
+    @Override
+    public JavaType getContentType() {
+        return _type.getContentType();
+    }
+
+    @Override
+    public boolean hasSingleElement(Multimap<?,?> map) {
+        return map.size() == 1;
+    }
+
+    @Override
+    public boolean isEmpty(Multimap<?,?> map) {
+        return map.isEmpty();
+    }
+    
+    /*
+    /**********************************************************
+    /* Post-processing (contextualization)
     /**********************************************************
      */
 

src/test/java/com/fasterxml/jackson/datatype/guava/TestMultimaps.java

@@ -1,16 +1,10 @@
 package com.fasterxml.jackson.datatype.guava;
 
+import com.fasterxml.jackson.annotation.*;
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.google.common.collect.ArrayListMultimap;
-import com.google.common.collect.HashMultimap;
-import com.google.common.collect.ImmutableMultimap;
-import com.google.common.collect.LinkedHashMultimap;
-import com.google.common.collect.LinkedListMultimap;
-import com.google.common.collect.ListMultimap;
-import com.google.common.collect.Multimap;
-import com.google.common.collect.SetMultimap;
-import com.google.common.collect.TreeMultimap;
+
+import com.google.common.collect.*;
 
 import java.io.IOException;
 import java.util.Map;
@@ -24,10 +18,23 @@
  */
 public class TestMultimaps extends BaseTest
 {
+    // Test for issue #13 on github, provided by stevenschlansker
+    public static enum MyEnum {
+        YAY,
+        BOO
+    }
+
+    // [Issue#41]
+    @JsonInclude(JsonInclude.Include.NON_EMPTY)
+    static class MultiMapWrapper {
+        @JsonProperty
+        Multimap<String, String> map = ArrayListMultimap.create();
+    }
+
     private static final String StringStringMultimap =
             "{\"first\":[\"abc\",\"abc\",\"foo\"]," + "\"second\":[\"bar\"]}";
 
-    private final ObjectMapper MAPPER =  mapperWithModule();
+    private final ObjectMapper MAPPER = mapperWithModule();
 
     public void testMultimap() throws Exception
     {
@@ -98,12 +105,6 @@ public void testMultimapIssue3() throws Exception
         javaMap = o.readValue(t4, Map.class);
         assertEquals(2, javaMap.size());
     }
-    
-    // Test for issue #13 on github, provided by stevenschlansker
-    public static enum MyEnum {
-        YAY,
-        BOO
-    }
 
     public void testEnumKey() throws Exception
     {
@@ -119,6 +120,13 @@ public void testEnumKey() throws Exception
         assertEquals(map, MAPPER.readValue(serializedForm, type));
     }
 
+    // [Issue#41]
+    public void testEmptyMapExclusion() throws Exception
+    {
+        String json = MAPPER.writeValueAsString(new MultiMapWrapper());
+        assertEquals("{}", json);
+    }
+    
     /*
     /**********************************************************************
     /* Unit tests for set-based multimaps