Fix #1999

Author: cowtowncoder

release-notes/CREDITS-2.x

@@ -767,3 +767,7 @@ roeltje25@github
   * Reported #1978: Using @JsonUnwrapped annotation in builderdeserializer hangs in
     infinite loop
    (2.9.5)
+
+Ondrej Zizka (OndraZizk@github)
+  * Reported #1999: "Duplicate property" issue should mention which class it complains about
+   (2.9.6)

release-notes/VERSION-2.x

@@ -14,6 +14,8 @@ Project: jackson-databind
 #1998: Removing "type" attribute with Mixin not taken in account if
   using ObjectMapper.copy()
  (reported by SBKila@github)
+#1999: "Duplicate property" issue should mention which class it complains about
+ (reported by Ondrej Z)
 
 2.9.5 (26-Mar-2018)
 

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

@@ -419,7 +419,7 @@ protected void _addDeserializerConstructors(DeserializationContext ctxt,
             BeanDescription beanDesc, VisibilityChecker<?> vchecker,
          AnnotationIntrospector intr, CreatorCollector creators,
          Map<AnnotatedWithParams,BeanPropertyDefinition[]> creatorParams)
-        throws JsonMappingException
+                 throws JsonMappingException
     {
         // 25-Jan-2017, tatu: As per [databind#1501], [databind#1502], [databind#1503], best
         //     for now to skip attempts at using anything but no-args constructor (see

src/main/java/com/fasterxml/jackson/databind/deser/impl/CreatorCollector.java

@@ -184,8 +184,8 @@ public void addPropertyCreator(AnnotatedWithParams creator,
                     Integer old = names.put(name, Integer.valueOf(i));
                     if (old != null) {
                         throw new IllegalArgumentException(String.format(
-                                "Duplicate creator property \"%s\" (index %s vs %d)",
-                                name, old, i));
+                                "Duplicate creator property \"%s\" (index %s vs %d) for type %s ",
+                                name, old, i, ClassUtil.nameOf(_beanDesc.getBeanClass())));
                     }
                 }
             }

src/test/java/com/fasterxml/jackson/databind/deser/creators/TestCreators2.java

@@ -261,6 +261,8 @@ public void testCreatorWithDupNames() throws Exception
             fail("Should have caught duplicate creator parameters");
         } catch (JsonMappingException e) {
             verifyException(e, "duplicate creator property \"bar\"");
+            verifyException(e, "for type `com.fasterxml.jackson.databind.");
+            verifyException(e, "$BrokenCreatorBean`");
         }
     }