Fix #2349

FasterXML · Aug 28, 2019 · ad74329 · ad74329
1 parent bc59123
commit ad74329
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Showing 3 changed files with 48 additions and 3 deletions.
diff --git a/release-notes/VERSION-2.x b/release-notes/VERSION-2.x
@@ -10,6 +10,7 @@ Project: jackson-databind
  (reported by sunchezz89@github)
 #2336: `MapDeserializer` can not merge `Map`s with polymorphic values
  (reported by Robert G)
+#2349: Add option `DefaultTyping.EVERYTHING` to support Kotlin data classes
 #2390: `Iterable` serialization breaks when adding `@JsonFilter` annotation
  (reported by Chris M)
 #2392: `BeanDeserializerModifier.modifyDeserializer()` not applied to custom bean deserializers

diff --git a/src/main/java/com/fasterxml/jackson/databind/ObjectMapper.java b/src/main/java/com/fasterxml/jackson/databind/ObjectMapper.java
@@ -184,7 +184,23 @@ public enum DefaultTyping {
          *<p>
          * Since 2.4, this does NOT apply to {@link TreeNode} and its subtypes.
          */
-        NON_FINAL
+        NON_FINAL,
+
+        /**
+         * Value that means that default typing will be used for
+         * all non-final types, with exception of small number of
+         * "natural" types (String, Boolean, Integer, Double) that
+         * can be correctly inferred from JSON, and primitives (which
+         * can not be polymorphic either). Typing is also enabled for
+         * all array types.
+         *<p>
+         * Note that the only known use case for this setting is for serialization
+         * when passing instances of final class, and base type is not
+         * separately specified.
+         *
+         * @since 2.10
+         */
+        EVERYTHING
     }
 
     /**
@@ -299,8 +315,12 @@ public boolean useForType(JavaType t)
                 }
                 // [databind#88] Should not apply to JSON tree models:
                 return !t.isFinal() && !TreeNode.class.isAssignableFrom(t.getRawClass());
+            case EVERYTHING:
+                // So, excluding primitives (handled earlier) and "Natural types" (handled
+                // before this method is called), applied to everything
+                return true;
             default:
-            //case JAVA_LANG_OBJECT:
+            case JAVA_LANG_OBJECT:
                 return t.isJavaLangObject();
             }
         }

diff --git a/src/test/java/com/fasterxml/jackson/databind/jsontype/deftyping/TestDefaultForObject.java b/src/test/java/com/fasterxml/jackson/databind/jsontype/deftyping/TestDefaultForObject.java
@@ -22,6 +22,11 @@ static class StringBean extends AbstractBean { // ha, punny!
         protected StringBean(String n)  { name = n; }
     }
 
+    final static class FinalStringBean extends StringBean {
+        protected FinalStringBean() { this(null); }
+        public FinalStringBean(String n)  { super(n); }
+    }
+
     enum Choice { YES, NO; }
 
     /**
@@ -377,7 +382,26 @@ public void testNoGoWithExternalProperty() throws Exception
             verifyException(e, "Cannot use includeAs of EXTERNAL_PROPERTY");
         }
     }
-
+
+    // [databind#2349]
+    public void testWithFinalClass() throws Exception
+    {
+        // First: type info NOT included
+        ObjectMapper mapper = JsonMapper.builder()
+                .activateDefaultTyping(NoCheckSubTypeValidator.instance,
+                        ObjectMapper.DefaultTyping.NON_FINAL)
+                .build();
+        assertEquals(aposToQuotes("{'name':'abc'}"),
+                mapper.writeValueAsString(new FinalStringBean("abc")));
+
+        mapper = JsonMapper.builder()
+                .activateDefaultTyping(NoCheckSubTypeValidator.instance,
+                        ObjectMapper.DefaultTyping.EVERYTHING)
+                .build();
+        assertEquals(aposToQuotes("['"+FinalStringBean.class.getName()+"',{'name':'abc'}]"),
+                mapper.writeValueAsString(new FinalStringBean("abc")));
+    }
+
     /*
     /**********************************************************
     /* Helper methods