Remove one unnecessary change (wrt Map defaulting), add a test case

FasterXML · Nov 12, 2024 · 7f985f0 · 7f985f0
1 parent 8efc34d
commit 7f985f0
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Showing 2 changed files with 32 additions and 7 deletions.
diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/BasicDeserializerFactory.java b/src/main/java/com/fasterxml/jackson/databind/deser/BasicDeserializerFactory.java
@@ -966,12 +966,18 @@ public JsonDeserializer<?> createMapDeserializer(DeserializationContext ctxt,
              */
             if (deser == null) {
                 if (type.isInterface() || type.isAbstract()) {
-                    MapType fallback = _mapAbstractMapType(type, config);
-                    if (fallback != null) {
-                        type = (MapType) fallback;
+                    MapType implType = _mapAbstractMapType(type, config);
+                    if (implType != null) {
+                        type = (MapType) implType;
                         mapClass = type.getRawClass();
                         // But if so, also need to re-check creators...
                         beanDesc = config.introspectForCreation(type);
+                    } else {
+                        // [databind#292]: Actually, may be fine, but only if polymorphic deser enabled
+                        if (type.getTypeHandler() == null) {
+                            throw new IllegalArgumentException("Cannot find a deserializer for non-concrete Map type "+type);
+                        }
+                        deser = AbstractDeserializer.constructForNonPOJO(beanDesc);
                     }
                 } else {
                     // 10-Jan-2017, tatu: `java.util.Collections` types need help:

diff --git a/src/test/java/com/fasterxml/jackson/databind/deser/merge/CustomCollectionMerge4783Test.java b/src/test/java/com/fasterxml/jackson/databind/deser/merge/CustomCollectionMerge4783Test.java
@@ -18,7 +18,7 @@
 // [databind#4783] Test to verify that JsonMerge also works for custom list
 @SuppressWarnings("serial")
 public class CustomCollectionMerge4783Test
-        extends DatabindTestUtil
+    extends DatabindTestUtil
 {
     static class MyArrayListJDK<T> extends ArrayList<T> { }
 
@@ -33,6 +33,11 @@ interface MyListCustom<T> extends List<T> { }
 
     static class MyArrayListCustom<T> extends ArrayList<T> implements MyListCustom<T> { }
 
+    static abstract class MyAbstractStringList extends ArrayList<String> {
+        MyAbstractStringList() { super(); }
+        MyAbstractStringList(int i) { super(); }
+    }
+
     static class MergeCustomStringList {
         @JsonMerge
         @JsonProperty
@@ -61,7 +66,7 @@ static class MergeMyCustomPojoList {
     static class NonMergeCustomStringList {
         public MyListCustom<String> values;
     }
-    
+
     public static class CustomPojo {
         public String name;
         public int age;
@@ -113,9 +118,11 @@ void testCustomMapperReadingPojoArrayList() throws Exception {
         assertEquals(3, result.values.size());
     }
 
-    // Failure-handling testing important too
+    // // // And then failure cases
+
+    // Fail can't construct Collection interface unless there's maaping
     @Test
-    void testNonMergeAbstractListFail() throws Exception {
+    void failNonMergeInterfaceList() throws Exception {
         try {
             MAPPER.readValue("{\"values\":[\"x\"]}", NonMergeCustomStringList.class);
             fail("Should not pass");
@@ -126,4 +133,16 @@ void testNonMergeAbstractListFail() throws Exception {
         }
     }
 
+    // Fail can't construct abstract types
+    @Test
+    void failNonMergeAbstractList() throws Exception {
+        try {
+            MAPPER.readValue("[]", MyAbstractStringList.class);
+            fail("Should not pass");
+        } catch (InvalidDefinitionException e) {
+            verifyException(e, String.format(
+                    "Cannot construct instance of `%s` (no Creators",
+                    MyAbstractStringList.class.getName()));
+        }
+    }
 }