Fix #61 for 2.3[.6]

FasterXML · Jan 23, 2015 · 0b31437 · 0b31437
1 parent 155f55f
commit 0b31437
Show file tree

Hide file tree

Showing 3 changed files with 34 additions and 17 deletions.
diff --git a/release-notes/VERSION b/release-notes/VERSION
@@ -4,6 +4,11 @@ Project: jackson-datatype-guava
 === History: ===
 ------------------------------------------------------------------------
 
+2.3.6 (not yet released)
+
+#61: NPE when serializing `Multimap`s with null values
+ (reported by sixinli@github)
+
 2.3.5 (14-Jan-2015)
 
 #46: Can not serialize Guava `Iterable`s (backported from 2.4.2)

diff --git a/src/main/java/com/fasterxml/jackson/datatype/guava/ser/MultimapSerializer.java b/src/main/java/com/fasterxml/jackson/datatype/guava/ser/MultimapSerializer.java
@@ -124,53 +124,57 @@ public boolean hasSingleElement(Multimap<?,?> map) {
     public boolean isEmpty(Multimap<?,?> map) {
         return map.isEmpty();
     }
-    
+
     /*
     /**********************************************************
     /* Post-processing (contextualization)
     /**********************************************************
      */
 
     @Override
-    public void serialize(Multimap<?, ?> value, JsonGenerator jgen, SerializerProvider provider)
+    public void serialize(Multimap<?, ?> value, JsonGenerator gen, SerializerProvider provider)
             throws IOException, JsonProcessingException
     {
-        jgen.writeStartObject();
+        gen.writeStartObject();
         if (!value.isEmpty()) {
-            serializeFields(value, jgen, provider);
+            serializeFields(value, gen, provider);
         }        
-        jgen.writeEndObject();
+        gen.writeEndObject();
     }
 
     @Override
-    public void serializeWithType(Multimap<?,?> value, JsonGenerator jgen, SerializerProvider provider,
+    public void serializeWithType(Multimap<?,?> value, JsonGenerator gen, SerializerProvider provider,
             TypeSerializer typeSer)
         throws IOException, JsonGenerationException
     {
-        typeSer.writeTypePrefixForObject(value, jgen);
-        serializeFields(value, jgen, provider);
-        typeSer.writeTypeSuffixForObject(value, jgen);
+        typeSer.writeTypePrefixForObject(value, gen);
+        serializeFields(value, gen, provider);
+        typeSer.writeTypeSuffixForObject(value, gen);
     }
 
-    private final void serializeFields(Multimap<?, ?> value, JsonGenerator jgen, SerializerProvider provider)
+    private final void serializeFields(Multimap<?, ?> value, JsonGenerator gen, SerializerProvider provider)
             throws IOException, JsonProcessingException
     {
         for (Entry<?, ? extends Collection<?>> e : value.asMap().entrySet()) {
             if (_keySerializer != null) {
-                _keySerializer.serialize(e.getKey(), jgen, provider);
+                _keySerializer.serialize(e.getKey(), gen, provider);
             } else {
                 provider.findKeySerializer(provider.constructType(String.class), _property)
-                    .serialize(e.getKey(), jgen, provider);
+                    .serialize(e.getKey(), gen, provider);
             }
             if (_valueSerializer != null) {
                 // note: value is a List, but generic type is for contents... so:
-                jgen.writeStartArray();
+                gen.writeStartArray();
                 for (Object vv : e.getValue()) {
-                    _valueSerializer.serialize(vv, jgen, provider);
+                    if (vv == null) { 
+                        provider.defaultSerializeNull(gen);
+                    } else {
+                        _valueSerializer.serialize(vv, gen, provider);
+                    }
                 }
-                jgen.writeEndArray();
+                gen.writeEndArray();
             } else {
-                provider.defaultSerializeValue(Lists.newArrayList(e.getValue()), jgen);
+                provider.defaultSerializeValue(Lists.newArrayList(e.getValue()), gen);
             }
         }
     }

diff --git a/src/test/java/com/fasterxml/jackson/datatype/guava/TestMultimaps.java b/src/test/java/com/fasterxml/jackson/datatype/guava/TestMultimaps.java
@@ -126,7 +126,15 @@ public void testEmptyMapExclusion() throws Exception
         String json = MAPPER.writeValueAsString(new MultiMapWrapper());
         assertEquals("{}", json);
     }
-
+
+    public void testNullHandling() throws Exception
+    {
+        Multimap<String,Integer> input = ArrayListMultimap.create();
+        input.put("empty", null);
+        String json = MAPPER.writeValueAsString(input);
+        assertEquals("{\"empty\":[null]}", json);
+    }
+
     /*
     /**********************************************************************
     /* Unit tests for set-based multimaps