Fix #52

release-notes/VERSION

@@ -6,7 +6,8 @@ Project: jackson-module-jaxb-annotations
 
 2.7.0 (not yet released)
 
-No changes since 2.6.
+#52: Add a feature in `JaxbAnnotationIntrospector` to define meaning of
+  `nillable=false` as "JsonInclude.NON_EMPTY"
 
 2.6.3 (12-Oct-2015)
 

src/main/java/com/fasterxml/jackson/module/jaxb/JaxbAnnotationIntrospector.java

@@ -10,11 +10,7 @@
 import javax.xml.bind.annotation.adapters.*;
 
 import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility;
-import com.fasterxml.jackson.annotation.JsonFormat;
-import com.fasterxml.jackson.annotation.JsonInclude;
-import com.fasterxml.jackson.annotation.JsonTypeInfo;
-import com.fasterxml.jackson.annotation.ObjectIdGenerators;
-import com.fasterxml.jackson.annotation.SimpleObjectIdResolver;
+import com.fasterxml.jackson.annotation.*;
 import com.fasterxml.jackson.core.*;
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.databind.cfg.MapperConfig;
@@ -103,7 +99,18 @@ public class JaxbAnnotationIntrospector
     protected String _xmlValueName = DEFAULT_NAME_FOR_XML_VALUE;
 
     /**
-     * @deprecated Since 2.1, use the ctor that takes TypeFactory
+     * Inclusion value to return for properties annotated with 
+     * {@link XmlElement} and {@link XmlElementWrapper}, in case <code>nillable</code>
+     * property is left as <code>false</false>. Default setting is
+     * <code>null</code>; this is typically changed to either
+     * {@link JsonInclude.Include#NON_NULL} or {@link JsonInclude.Include#NON_EMPTY}.
+     *
+     * @since 2.7
+     */
+    protected JsonInclude.Include _nonNillableInclusion = null;
+
+    /**
+     * @deprecated Since 2.1, use constructor that takes TypeFactory.
      */
     @Deprecated
     public JaxbAnnotationIntrospector() {
@@ -180,7 +187,26 @@ public void setNameUsedForXmlValue(String name) {
     public String getNameUsedForXmlValue() {
         return _xmlValueName;
     }
-
+
+    /**
+     * Method to call to change inclusion criteria used for property annotated
+     * with {@link XmlElement} or {@link XmlElementWrapper}, with <code>nillable</code>
+     * set as <code>false</code>.
+     *
+     * @since 2.7
+     */
+    public JaxbAnnotationIntrospector setNonNillableInclusion(JsonInclude.Include incl) {
+        _nonNillableInclusion = incl;
+        return this;
+    }
+
+    /**
+     * @since 2.7
+     */
+    public JsonInclude.Include getNonNillableInclusion() {
+        return _nonNillableInclusion;
+    }
+
     /*
     /**********************************************************
     /* Extended API (XmlAnnotationIntrospector)
@@ -707,27 +733,44 @@ public Class<?> findSerializationType(Annotated a)
      * Jackson defaults (which are configurable), and only using JAXB explicit annotations.
      */
     @Override
-    @Deprecated // since 2.7
+    @Deprecated // since 2.7; remove from 2.8
     public JsonInclude.Include findSerializationInclusion(Annotated a, JsonInclude.Include defValue)
     {
         XmlElementWrapper w = a.getAnnotation(XmlElementWrapper.class);
         if (w != null) {
             if (w.nillable()) {
                 return JsonInclude.Include.ALWAYS;
             }
+            // [jaxb-annotations#52]: Allow specifying inclusion for `nillable=false` too
+            if (_nonNillableInclusion != null) {
+                return _nonNillableInclusion;
+            }
         }
         XmlElement e = a.getAnnotation(XmlElement.class);
         if (e != null) {
             if (e.nillable()) {
                 return JsonInclude.Include.ALWAYS;
             }
+            // [jaxb-annotations#52]: Allow specifying inclusion for `nillable=false` too
+            if (_nonNillableInclusion != null) {
+                return _nonNillableInclusion;
+            }
         }
         //better pass default value through, if no explicit direction indicating otherwise
         return defValue;
     }
 
-    // @since 2.7
-    @Override
+    @Override // @since 2.7
+    public JsonInclude.Value findPropertyInclusion(Annotated a)
+    {
+        JsonInclude.Include incl = findSerializationInclusion(a, null);
+        if (incl == null) {
+            return JsonInclude.Value.empty();
+        }
+        return JsonInclude.Value.construct(incl, null);
+    }
+
+    @Override // @since 2.7
     public JavaType refineSerializationType(final MapperConfig<?> config,
             final Annotated a, final JavaType baseType) throws JsonMappingException
     {
@@ -888,9 +931,8 @@ public boolean hasAsValueAnnotation(AnnotatedMethod am) {
 
     /**
      *<p>
-     * !!! 12-Oct-2009, tatu: This is hideously slow implementation,
-     *   called potentially for every single enum value being
-     *   serialized. Should improve...
+     * This is very slow implementation, but as of Jackson 2.7, should not be called any more;
+     * instead, {@link #findEnumValues} should be called which has less overhead.
      */
     @Override
     public String findEnumValue(Enum<?> e)

src/main/java/com/fasterxml/jackson/module/jaxb/JaxbAnnotationModule.java

@@ -1,5 +1,6 @@
 package com.fasterxml.jackson.module.jaxb;
 
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.core.Version;
 import com.fasterxml.jackson.databind.Module;
 
@@ -39,14 +40,38 @@ public enum Priority {
      */
     protected Priority _priority = Priority.PRIMARY;
 
+    /**
+     * If the introspector is explicitly set or passed, we'll hold on to that
+     * until registration.
+     *
+     * @since 2.7
+     */
+    protected JaxbAnnotationIntrospector _introspector;
+
+    /**
+     * Value to pass to
+     * {@link JaxbAnnotationIntrospector#setNonNillableInclusion}
+     * if defined and non-null.
+     *
+     * @since 2.7
+     */
+    protected JsonInclude.Include _nonNillableInclusion;
+
     /*
     /**********************************************************
     /* Life cycle
     /**********************************************************
      */
-    
+
     public JaxbAnnotationModule() { }
 
+    /**
+     * @since 2.7
+     */
+    public JaxbAnnotationModule(JaxbAnnotationIntrospector intr) {
+        _introspector = intr;
+    }
+
     @Override
     public String getModuleName() {
         return getClass().getSimpleName();
@@ -60,7 +85,13 @@ public Version version() {
     @Override
     public void setupModule(SetupContext context)
     {
-        JaxbAnnotationIntrospector intr = new JaxbAnnotationIntrospector(context.getTypeFactory());
+        JaxbAnnotationIntrospector intr = _introspector;
+        if (intr == null) {
+            intr = new JaxbAnnotationIntrospector(context.getTypeFactory());
+            if (_nonNillableInclusion != null) {
+                intr.setNonNillableInclusion(_nonNillableInclusion);
+            }
+        }
         switch (_priority) {
         case PRIMARY:
             context.insertAnnotationIntrospector(intr);
@@ -91,4 +122,22 @@ public JaxbAnnotationModule setPriority(Priority p) {
     }
 
     public Priority getPriority() { return _priority; }
+
+    /**
+     * @since 2.7
+     */
+    public JaxbAnnotationModule setNonNillableInclusion(JsonInclude.Include incl) {
+        _nonNillableInclusion = incl;
+        if (_introspector != null) {
+            _introspector.setNonNillableInclusion(incl);
+        }
+        return this;
+    }
+
+    /**
+     * @since 2.7
+     */
+    public JsonInclude.Include getNonNillableInclusion() {
+        return _nonNillableInclusion;
+    }
 }

src/test/java/com/fasterxml/jackson/module/jaxb/misc/TestJaxbNullProperties.java

@@ -6,6 +6,8 @@
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.module.jaxb.BaseJaxbTest;
+import com.fasterxml.jackson.module.jaxb.JaxbAnnotationIntrospector;
+import com.fasterxml.jackson.module.jaxb.JaxbAnnotationModule;
 
 /**
  * Unit tests to ensure that handling of writing of null properties (or not)
@@ -28,8 +30,6 @@ public static class Bean
        public String x = "y";
     }
 
-    // Beans for [JACKSON-256]
-
     @XmlRootElement
     static class BeanWithNillable {
         public Nillable X;
@@ -39,6 +39,22 @@ static class BeanWithNillable {
     static class Nillable {
         @XmlElement (name="Z", nillable=true)
         Integer Z;
+
+        public Nillable() { }
+        public Nillable(int i) {
+            Z = Integer.valueOf(i);
+        }
+    } 
+
+    @XmlRootElement
+    static class NonNillableZ {
+        @XmlElement(name="z", nillable=false)
+        public Integer z;
+
+        public NonNillableZ() { }
+        public NonNillableZ(int i) {
+            z = Integer.valueOf(i);
+        }
     } 
 
     /*
@@ -49,19 +65,36 @@ static class Nillable {
 
     private final ObjectMapper MAPPER = getJaxbMapper();
 
-    // Test for [JACKSON-256], thanks John.
     public void testWriteNulls() throws Exception
     {
         BeanWithNillable bean = new BeanWithNillable();
         bean.X = new Nillable();
         assertEquals("{\"X\":{\"Z\":null}}", MAPPER.writeValueAsString(bean));
     }
 
-    // Testing [JACKSON-309]
     public void testNullProps() throws Exception
     {
         ObjectMapper mapper = getJaxbMapper();
         mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
         assertEquals("{\"x\":\"y\"}", mapper.writeValueAsString(new Bean()));
     }
+
+    public void testNillability() throws Exception
+    {
+        ObjectMapper mapper = getJaxbMapper();
+        // by default, something not marked as nillable will still be written if null
+        assertEquals("{\"z\":null}", mapper.writeValueAsString(new NonNillableZ()));
+        assertEquals("{\"z\":3}", mapper.writeValueAsString(new NonNillableZ(3)));
+
+        // but we can change that...
+        mapper = new ObjectMapper()
+            .registerModule(new JaxbAnnotationModule()
+                .setNonNillableInclusion(JsonInclude.Include.NON_NULL)
+                );
+        mapper.setAnnotationIntrospector(new JaxbAnnotationIntrospector(mapper.getTypeFactory())
+            .setNonNillableInclusion(JsonInclude.Include.NON_NULL)
+        );
+        assertEquals("{}", mapper.writeValueAsString(new NonNillableZ()));
+        assertEquals("{\"z\":3}", mapper.writeValueAsString(new NonNillableZ(3)));
+    }
 }