Refactoring for #1615

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

@@ -161,6 +161,52 @@ public JavaType constructSpecializedType(JavaType baseType, Class<?> subclass) {
         return getConfig().constructSpecializedType(baseType, subclass);
     }
 
+    /**
+     * Lookup method called when code needs to resolve class name from input;
+     * usually simple lookup
+     *
+     * @since 2.9
+     */
+    public JavaType resolveSubType(JavaType baseType, String subClass)
+        throws JsonMappingException
+    {
+        // 30-Jan-2010, tatu: Most ids are basic class names; so let's first
+        //    check if any generics info is added; and only then ask factory
+        //    to do translation when necessary
+        if (subClass.indexOf('<') > 0) {
+            // note: may want to try combining with specialization (esp for EnumMap)?
+            return getTypeFactory().constructFromCanonical(subClass);
+        }
+        Class<?> cls;
+        try {
+            cls =  getTypeFactory().findClass(subClass);
+        } catch (ClassNotFoundException e) { // let caller handle this problem
+            return null;
+        } catch (Exception e) {
+            throw invalidTypeIdException(baseType, subClass, String.format(
+                    "problem: (%s) %s",
+                    e.getClass().getName(), e.getMessage()));
+        }
+        if (baseType.isTypeOrSuperTypeOf(cls)) {
+            return getTypeFactory().constructSpecializedType(baseType, cls);
+        }
+        throw invalidTypeIdException(baseType, subClass, "Not a subtype");
+    }
+
+    /**
+     * Helper method for constructing exception to indicate that given type id
+     * could not be resolved to a valid subtype of specified base type.
+     * Most commonly called during polymorphic deserialization.
+     *<p>
+     * Note that most of the time this method should NOT be called directly: instead,
+     * method <code>handleUnknownTypeId()</code> should be called which will call this method
+     * if necessary.
+     *
+     * @since 2.9
+     */
+    protected abstract JsonMappingException invalidTypeIdException(JavaType baseType, String typeId,
+            String extraDesc);
+
     public abstract TypeFactory getTypeFactory();
 
     /*

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

@@ -1558,17 +1558,7 @@ public JsonMappingException instantiationException(Class<?> instClass, String ms
         return InvalidDefinitionException.from(_parser, msg, type);
     }
 
-    /**
-     * Helper method for constructing exception to indicate that given type id
-     * could not be resolved to a valid subtype of specified base type, during
-     * polymorphic deserialization.
-     *<p>
-     * Note that most of the time this method should NOT be called; instead,
-     * {@link #handleUnknownTypeId} should be called which will call this method
-     * if necessary.
-     *
-     * @since 2.9
-     */
+    @Override
     public JsonMappingException invalidTypeIdException(JavaType baseType, String typeId,
             String extraDesc) {
         String msg = String.format("Could not resolve type id '%s' as a subtype of %s",

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

@@ -13,6 +13,7 @@
 import com.fasterxml.jackson.databind.cfg.ContextAttributes;
 import com.fasterxml.jackson.databind.deser.ContextualDeserializer;
 import com.fasterxml.jackson.databind.exc.InvalidDefinitionException;
+import com.fasterxml.jackson.databind.exc.InvalidTypeIdException;
 import com.fasterxml.jackson.databind.introspect.Annotated;
 import com.fasterxml.jackson.databind.introspect.BeanPropertyDefinition;
 import com.fasterxml.jackson.databind.jsontype.TypeSerializer;
@@ -1222,6 +1223,14 @@ public void reportMappingProblem(Throwable t, String message, Object... msgArgs)
         throw JsonMappingException.from(getGenerator(), message, t);
     }
 
+    @Override
+    public JsonMappingException invalidTypeIdException(JavaType baseType, String typeId,
+            String extraDesc) {
+        String msg = String.format("Could not resolve type id '%s' as a subtype of %s",
+                typeId, baseType);
+        return InvalidTypeIdException.from(null, _colonConcat(msg, extraDesc), baseType, typeId);
+    }
+
     /*
     /********************************************************
     /* Error reporting, deprecated methods

src/main/java/com/fasterxml/jackson/databind/jsontype/impl/ClassNameIdResolver.java

@@ -39,42 +39,20 @@ public String idFromValueAndType(Object value, Class<?> type) {
 
     @Override
     public JavaType typeFromId(DatabindContext context, String id) throws IOException {
-        return _typeFromId(id, (DeserializationContext) context);
+        return _typeFromId(id, context);
     }
 
     protected JavaType _typeFromId(String id, DatabindContext ctxt) throws IOException
     {
-        /* 30-Jan-2010, tatu: Most ids are basic class names; so let's first
-         *    check if any generics info is added; and only then ask factory
-         *    to do translation when necessary
-         */
-        TypeFactory tf = ctxt.getTypeFactory();
-        if (id.indexOf('<') > 0) {
-            // note: may want to try combining with specialization (esp for EnumMap)?
-            return tf.constructFromCanonical(id);
-        }
-        Class<?> cls;
-        try {
-            cls =  tf.findClass(id);
-        } catch (ClassNotFoundException e) {
-            // 24-May-2016, tatu: Ok, this is pretty ugly, but we should always get
-            //   DeserializationContext, just playing it safe
+        JavaType t = ctxt.resolveSubType(_baseType, id);
+        if (t == null) {
             if (ctxt instanceof DeserializationContext) {
-                DeserializationContext dctxt = (DeserializationContext) ctxt;
                 // First: we may have problem handlers that can deal with it?
-                return dctxt.handleUnknownTypeId(_baseType, id, this, "no such class found");
+                return ((DeserializationContext) ctxt).handleUnknownTypeId(_baseType, id, this, "no such class found");
             }
             // ... meaning that we really should never get here.
-            return null;
-        } catch (Exception e) {
-            throw ((DeserializationContext) ctxt).invalidTypeIdException(_baseType, id, String.format(
-                    "Invalid type id, problem: (%s) %s",
-                    e.getClass().getName(), e.getMessage()));
-        }
-        if (_baseType.isTypeOrSuperTypeOf(cls)) {
-            return tf.constructSpecializedType(_baseType, cls);
         }
-        throw ((DeserializationContext) ctxt).invalidTypeIdException(_baseType, id, "Not a subtype");
+        return t;
     }
 
     /*

src/main/java/com/fasterxml/jackson/databind/type/TypeFactory.java

@@ -302,8 +302,8 @@ public Class<?> findClass(String className) throws ClassNotFoundException
     }
 
     protected Class<?> classForName(String name, boolean initialize,
-                                   ClassLoader loader) throws ClassNotFoundException {
-    	return Class.forName(name, true, loader);
+            ClassLoader loader) throws ClassNotFoundException {
+        return Class.forName(name, true, loader);
     }
 
     protected Class<?> classForName(String name) throws ClassNotFoundException {