Fixed #700 (cannot change default Map, List)

release-notes/VERSION

@@ -9,6 +9,8 @@ Project: jackson-databind
 #649: Make `BeanDeserializer` use new `parser.nextFieldName()` and `.hasTokenId()` methods
 #696: Copy constructor does not preserve `_injectableValues`
  (reported by Charles A)
+#700: Cannot Change Default Abstract Type Mapper from LinkedHashMap
+ (reported by wealdtech@github)
 
 2.5.2 (not yet released)
 

src/main/java/com/fasterxml/jackson/databind/DeserializationContext.java

@@ -42,7 +42,7 @@ public abstract class DeserializationContext
     extends DatabindContext
     implements java.io.Serializable
 {
-    private static final long serialVersionUID = -4290063686213707727L;
+    private static final long serialVersionUID = 1L; // 2.6
 
     /**
      * Let's limit length of error messages, for cases where underlying data

src/main/java/com/fasterxml/jackson/databind/deser/BasicDeserializerFactory.java

@@ -178,24 +178,21 @@ public final DeserializerFactory withValueInstantiators(ValueInstantiators insta
 
     /*
     /**********************************************************
-    /* JsonDeserializerFactory impl (partial): type mappings
+    /* DeserializerFactory impl (partial): type mappings
     /**********************************************************
      */
 
     @Override
-    public JavaType mapAbstractType(DeserializationConfig config, JavaType type)
-        throws JsonMappingException
+    public JavaType mapAbstractType(DeserializationConfig config, JavaType type) throws JsonMappingException
     {
         // first, general mappings
         while (true) {
             JavaType next = _mapAbstractType2(config, type);
             if (next == null) {
                 return type;
             }
-            /* Should not have to worry about cycles; but better verify since they will invariably
-             * occur... :-)
-             * (also: guard against invalid resolution to a non-related type)
-             */
+            // Should not have to worry about cycles; but better verify since they will invariably occur... :-)
+            // (also: guard against invalid resolution to a non-related type)
             Class<?> prevCls = type.getRawClass();
             Class<?> nextCls = next.getRawClass();
             if ((prevCls == nextCls) || !prevCls.isAssignableFrom(nextCls)) {
@@ -1437,7 +1434,17 @@ public JsonDeserializer<?> findDefaultDeserializer(DeserializationContext ctxt,
         Class<?> rawType = type.getRawClass();
         // Object ("untyped"), String equivalents:
         if (rawType == CLASS_OBJECT) {
-            return new UntypedObjectDeserializer();
+            // 11-Feb-2015, tatu: As per [databind#700] need to be careful wrt non-default Map, List.
+            DeserializationConfig config = ctxt.getConfig();
+            JavaType lt, mt;
+
+            if (_factoryConfig.hasAbstractTypeResolvers()) {
+                lt = _findRemappedType(config, List.class);
+                mt = _findRemappedType(config, Map.class);
+            } else {
+                lt = mt = null;
+            }
+            return new UntypedObjectDeserializer(lt, mt);
         }
         if (rawType == CLASS_STRING || rawType == CLASS_CHAR_BUFFER) {
             return StringDeserializer.instance;
@@ -1507,6 +1514,11 @@ public JsonDeserializer<?> findDefaultDeserializer(DeserializationContext ctxt,
         return JdkDeserializers.find(rawType, clsName);
     }
 
+    protected JavaType _findRemappedType(DeserializationConfig config, Class<?> rawType) throws JsonMappingException {
+        JavaType type = mapAbstractType(config, config.constructType(rawType));
+        return (type == null || type.hasRawClass(rawType)) ? null : type;
+    }
+
     /*
     /**********************************************************
     /* Helper methods, finding custom deserializers

src/main/java/com/fasterxml/jackson/databind/deser/std/UntypedObjectDeserializer.java

@@ -41,7 +41,7 @@ public class UntypedObjectDeserializer
      * @deprecated Since 2.3, construct a new instance, needs to be resolved
      */
     @Deprecated
-    public final static UntypedObjectDeserializer instance = new UntypedObjectDeserializer();
+    public final static UntypedObjectDeserializer instance = new UntypedObjectDeserializer(null, null);
 
     /*
     /**********************************************************
@@ -56,9 +56,35 @@ public class UntypedObjectDeserializer
     protected JsonDeserializer<Object> _stringDeserializer;
 
     protected JsonDeserializer<Object> _numberDeserializer;
-
+
+    /**
+     * If {@link java.util.List} has been mapped to non-default implementation,
+     * we'll store type here
+     *
+     * @since 2.6
+     */
+    protected JavaType _listType;
+
+    /**
+     * If {@link java.util.Map} has been mapped to non-default implementation,
+     * we'll store type here
+     *
+     * @since 2.6
+     */
+    protected JavaType _mapType;
+
+    /**
+     * @deprecated Since 2.6 use variant takes type arguments
+     */
+    @Deprecated
     public UntypedObjectDeserializer() {
+        this(null, null);
+    }
+
+    public UntypedObjectDeserializer(JavaType listType, JavaType mapType) {
         super(Object.class);
+        _listType = listType;
+        _mapType = mapType;
     }
 
     @SuppressWarnings("unchecked")
@@ -71,6 +97,8 @@ public UntypedObjectDeserializer(UntypedObjectDeserializer base,
         _listDeserializer = (JsonDeserializer<Object>) listDeser;
         _stringDeserializer = (JsonDeserializer<Object>) stringDeser;
         _numberDeserializer = (JsonDeserializer<Object>) numberDeser;
+        _listType = base._listType;
+        _mapType = base._mapType;
     }
 
     /*
@@ -102,8 +130,16 @@ public void resolve(DeserializationContext ctxt) throws JsonMappingException
          */
 
         // So: first find possible custom instances
-        _mapDeserializer = _findCustomDeser(ctxt, tf.constructMapType(Map.class, stringType, obType));
-        _listDeserializer = _findCustomDeser(ctxt, tf.constructCollectionType(List.class, obType));
+        if (_listType == null) {
+            _listDeserializer = _clearIfStdImpl(_findCustomDeser(ctxt, tf.constructCollectionType(List.class, obType)));
+        } else {
+            _listDeserializer = _findCustomDeser(ctxt, _listType);
+        }
+        if (_mapType == null) {
+            _mapDeserializer = _clearIfStdImpl(_findCustomDeser(ctxt, tf.constructMapType(Map.class, stringType, obType)));
+        } else {
+            _mapDeserializer = _findCustomDeser(ctxt, _mapType);
+        }
         _stringDeserializer = _findCustomDeser(ctxt, stringType);
         _numberDeserializer = _findCustomDeser(ctxt, tf.constructType(Number.class));
 
@@ -116,17 +152,16 @@ public void resolve(DeserializationContext ctxt) throws JsonMappingException
         _numberDeserializer = (JsonDeserializer<Object>) ctxt.handleSecondaryContextualization(_numberDeserializer, null, unknown);
     }
 
-    @SuppressWarnings("unchecked")
     protected JsonDeserializer<Object> _findCustomDeser(DeserializationContext ctxt, JavaType type)
         throws JsonMappingException
     {
         // Since we are calling from `resolve`, we should NOT try to contextualize yet;
         // contextualization will only occur at a later point
-        JsonDeserializer<?> deser = ctxt.findNonContextualValueDeserializer(type);
-        if (ClassUtil.isJacksonStdImpl(deser)) {
-            return null;
-        }
-        return (JsonDeserializer<Object>) deser;
+        return ctxt.findNonContextualValueDeserializer(type);
+    }
+
+    protected JsonDeserializer<Object> _clearIfStdImpl(JsonDeserializer<Object> deser) {
+        return ClassUtil.isJacksonStdImpl(deser) ? null : deser;
     }
 
     /**

src/test/java/com/fasterxml/jackson/databind/module/TestAbstractTypes.java

@@ -2,7 +2,6 @@
 
 import java.util.*;
 
-
 import com.fasterxml.jackson.core.Version;
 import com.fasterxml.jackson.databind.BaseMapTest;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -65,22 +64,34 @@ public void testMapDefaultingBasic() throws Exception
         assertEquals(TreeMap.class, result.getClass());
     }
 
-    /* 11-Feb-2015, tatu: too tricky to fix in 2.5.x; move to 2.6
     // [databind#700]
-    public void testMapDefaultingRecursive() throws Exception
+    public void testDefaultingRecursive() throws Exception
     {
         ObjectMapper mapper = new ObjectMapper();
         SimpleModule mod = new SimpleModule("test", Version.unknownVersion());
-        // default is HashMap, so:
+
+        // defaults: LinkedHashMap, ArrayList
         mod.addAbstractTypeMapping(Map.class, TreeMap.class);
+        mod.addAbstractTypeMapping(List.class, LinkedList.class);
+
         mapper.registerModule(mod);
-        Object result = mapper.readValue("[ {} ]", Object.class);
-        assertEquals(ArrayList.class, result.getClass());
+        Object result;
+
+        result = mapper.readValue("[ {} ]", Object.class);
+        assertEquals(LinkedList.class, result.getClass());
         Object v = ((List<?>) result).get(0);
         assertNotNull(v);
         assertEquals(TreeMap.class, v.getClass());
+
+        result = mapper.readValue("{ \"x\": [ 3 ] }", Object.class);
+        assertEquals(TreeMap.class, result.getClass());
+        Map<?,?> map = (Map<?,?>) result;
+        assertEquals(1, map.size());
+        v = map.get("x");
+        assertNotNull(v);
+        assertEquals(LinkedList.class, v.getClass());
+        assertEquals(1, ((List<?>) v).size());
     }
-    */
 
     public void testInterfaceDefaulting() throws Exception
     {