Fix AutoGeneratedTimestampRecordExtension failing on @DynamoDbConvertedBy list attributes

.changes/next-release/bugfix-AmazonDynamoDBEnhancedClient-e8e2684.json

@@ -0,0 +1,6 @@
+{
+    "type": "bugfix",
+    "category": "Amazon DynamoDB Enhanced Client",
+    "contributor": "",
+    "description": "Fix AutoGeneratedTimestampRecordExtension failing on @DynamoDbConvertedBy list attributes"
+}

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/internal/extensions/utility/NestedRecordUtils.java

@@ -28,6 +28,8 @@
 import software.amazon.awssdk.enhanced.dynamodb.AttributeConverter;
 import software.amazon.awssdk.enhanced.dynamodb.EnhancedType;
 import software.amazon.awssdk.enhanced.dynamodb.TableSchema;
+import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbBean;
+import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbImmutable;
 import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
 import software.amazon.awssdk.utils.CollectionUtils;
 import software.amazon.awssdk.utils.StringUtils;
@@ -49,13 +51,18 @@
      * If the provided key contains the nested object delimiter (e.g., {@code _NESTED_ATTR_UPDATE_}), the method traverses the
      * nested hierarchy based on that path to locate the correct schema for the target attribute. Otherwise, it directly resolves
      * the list element type from the root schema using reflection.
+     * <p>
+     * If the list element type is not annotated with {@code @DynamoDbBean} or {@code @DynamoDbImmutable} (e.g. when a custom
+     * converter handles serialization via {@code @DynamoDbConvertedBy}), this method returns {@code null} to indicate that no
+     * schema introspection is possible or necessary for that element type.
      *
      * @param rootSchema The root {@link TableSchema} representing the top-level entity.
      * @param key        The key representing the list attribute, either flat or nested (using a delimiter).
-     * @return The {@link TableSchema} representing the list element type of the specified attribute.
-     * @throws IllegalArgumentException If the list element class cannot be found via reflection.
+     * @return The {@link TableSchema} representing the list element type, or {@code null} if the element type is not a
+     *         DynamoDB-annotated class.
+     * @throws IllegalArgumentException If no converter is found for the attribute or if the converter has no type parameters.
      */
     public static TableSchema<?> getTableSchemaForListElement(TableSchema<?> rootSchema, String key) {
         return getTableSchemaForListElement(rootSchema, key, new HashMap<>());
     }
 
@@ -63,7 +70,7 @@
      * Same as {@link #getTableSchemaForListElement(TableSchema, String)} but allows callers to provide a shared per-operation
      * cache for nested schema lookups.
      */
     public static TableSchema<?> getTableSchemaForListElement(
         TableSchema<?> rootSchema,
         String key,
         Map<SchemaLookupKey, Optional<TableSchema<?>>> nestedSchemaCache) {
@@ -85,7 +92,12 @@
         if (CollectionUtils.isNullOrEmpty(rawClassParameters)) {
             throw new IllegalArgumentException("No type parameters found for list attribute: " + key);
         }
-        return TableSchema.fromClass(rawClassParameters.get(0).rawClass());
+        Class<?> elementClass = rawClassParameters.get(0).rawClass();
+        if (elementClass.getAnnotation(DynamoDbBean.class) == null
+            && elementClass.getAnnotation(DynamoDbImmutable.class) == null) {
+            return null;
+        }
+        return TableSchema.fromClass(elementClass);
     }
 
     private static TableSchema<?> listElementSchemaForDelimitedKey(
@@ -212,10 +224,11 @@
     /**
      * Cached wrapper for resolving list element schema, storing results (including null) in the provided cache.
      * <p>
-     * Note: {@link #getTableSchemaForListElement(TableSchema, String, Map)} does not return null today, but this helper is used
-     * by callers that previously cached the list element schema separately, and it keeps the "cache null" behavior.
+     * {@link #getTableSchemaForListElement(TableSchema, String, Map)} returns {@code null} when the list element type is not a
+     * DynamoDB-annotated class (e.g. when a custom converter handles serialization). Callers should check for null before
+     * attempting to introspect the returned schema.
      */
     public static TableSchema<?> getListElementSchemaCached(
         Map<SchemaLookupKey, TableSchema<?>> cache,
         TableSchema<?> parentSchema,
         String attributeName,

services-custom/dynamodb-enhanced/src/test/java/software/amazon/awssdk/enhanced/dynamodb/functionaltests/AutoGeneratedTimestampExtensionTest.java

@@ -75,6 +75,9 @@
 import software.amazon.awssdk.enhanced.dynamodb.functionaltests.models.AutogeneratedTimestampTestModels.BeanWithInvalidNestedAttributeName;
 import software.amazon.awssdk.enhanced.dynamodb.functionaltests.models.AutogeneratedTimestampTestModels.BeanWithInvalidNestedAttributeName.BeanWithInvalidNestedAttributeNameChild;
 import software.amazon.awssdk.enhanced.dynamodb.functionaltests.models.AutogeneratedTimestampTestModels.BeanWithInvalidRootAttributeName;
+import software.amazon.awssdk.enhanced.dynamodb.functionaltests.models.AutogeneratedTimestampTestModels.BeanWithCustomConvertedList;
+import software.amazon.awssdk.enhanced.dynamodb.functionaltests.models.AutogeneratedTimestampTestModels.BeanWithCustomConvertedMap;
+import software.amazon.awssdk.enhanced.dynamodb.functionaltests.models.AutogeneratedTimestampTestModels.CustomConvertedPojo;
 import software.amazon.awssdk.enhanced.dynamodb.functionaltests.models.AutogeneratedTimestampTestModels.NestedBeanChild;
 import software.amazon.awssdk.enhanced.dynamodb.functionaltests.models.AutogeneratedTimestampTestModels.NestedBeanWithList;
 import software.amazon.awssdk.enhanced.dynamodb.functionaltests.models.AutogeneratedTimestampTestModels.NestedImmutableChildRecordWithList;
@@ -136,7 +139,7 @@
                               .build();
 
     @Rule
     public ExpectedException thrown = ExpectedException.none();
 
     @Before
     public void setup() {
@@ -1279,7 +1282,7 @@
     @Test
     public void beforeWrite_itemContainsOnlyStringList_thenStringListUnchanged() {
         TableSchema<SimpleBeanWithList> schema = BeanTableSchema.create(SimpleBeanWithList.class);
         SimpleBeanWithList record = new SimpleBeanWithList()
             .setId("1")
             .setChildStringList(Arrays.asList("a", "b"));
         record.setChildList(new ArrayList<>());
@@ -1296,7 +1299,7 @@
     public void beforeWrite_topLevelChildListHasMapsThenString_thenMapsTimestampedAndStringUnchanged() {
         String expectedWrittenInstant = MOCKED_INSTANT_NOW.toString();
         TableSchema<SimpleBeanWithList> schema = BeanTableSchema.create(SimpleBeanWithList.class);
         SimpleBeanWithList record = new SimpleBeanWithList()
             .setId("1")
             .setChildList(Arrays.asList(new SimpleBeanChild().setId("c1"), new SimpleBeanChild().setId("c2")));
 
@@ -1322,7 +1325,7 @@
         TableSchema<NestedBeanWithList> schema = BeanTableSchema.create(NestedBeanWithList.class);
         NestedBeanChild level2 = new NestedBeanChild();
         level2.setChildList(Arrays.asList(new SimpleBeanChild().setId("a"), new SimpleBeanChild().setId("b")));
         NestedBeanWithList record = new NestedBeanWithList().setId("1").setLevel2(level2);
 
         Map<String, AttributeValue> putItem = new HashMap<>(schema.itemToMap(record, false));
         Map<String, AttributeValue> level2Map = new HashMap<>(putItem.get("level2").m());
@@ -1345,7 +1348,7 @@
     @Test
     public void beforeWrite_nestedRecordHoldsAttributeNotOnSchema_thenThatSubtreeUnchanged() {
         TableSchema<NestedRecord> schema = createNestedRecordSchema();
         NestedRecord record = new NestedRecord()
             .setId("1")
             .setAttribute("x")
             .setNestedRecord(new NestedBeanChild().setChildList(Collections.emptyList()));
@@ -1369,7 +1372,7 @@
         TableSchema<?> tableSchema = mock(TableSchema.class);
         TableMetadata tableMetadata = mock(TableMetadata.class);
         when(tableSchema.tableMetadata()).thenReturn(tableMetadata);
         when(tableMetadata.customMetadataObject(eq(AUTO_TS_EXTENSION_METADATA_KEY), eq(Collection.class)))
             .thenReturn(Optional.of(Arrays.asList("validTs", "missingTs")));
 
         AttributeConverter<?> instantConverter =
@@ -1391,7 +1394,7 @@
     @Test
     public void beforeWrite_nestedMetadataNamesNonSchemaTimestamp_thenDeclaredInstantAttributeStillWritten() {
         TableSchema<RootWithNestedUnknownMetadataTimestampKey> schema = schemaRootWithNestedUnknownMetadataTimestampKey();
         RootWithNestedUnknownMetadataTimestampKey record = new RootWithNestedUnknownMetadataTimestampKey();
         record.setId("1");
         record.setNested(new NestedWithUnknownMetadataTimestampKey());
 
@@ -1407,7 +1410,7 @@
     public void beforeWrite_nestedDocumentHasTwoAutoTimestampFields_thenBothMatchClockInstant() {
         String expectedWrittenInstant = MOCKED_INSTANT_NOW.toString();
         TableSchema<RootWithNestedTwoAutoTimestamps> schema = schemaRootWithNestedTwoAutoTimestamps();
         RootWithNestedTwoAutoTimestamps record = new RootWithNestedTwoAutoTimestamps();
         record.setId("1");
         record.setNested(new NestedWithTwoAutoTimestamps());
 
@@ -1426,7 +1429,7 @@
         TableSchema<NestedBeanWithList> schema = BeanTableSchema.create(NestedBeanWithList.class);
         NestedBeanChild level2 = new NestedBeanChild();
         level2.setChildList(Collections.singletonList(new SimpleBeanChild().setId("c1")));
         NestedBeanWithList record = new NestedBeanWithList().setId("1").setLevel2(level2);
 
         Map<String, AttributeValue> putItem = new HashMap<>(schema.itemToMap(record, false));
         Map<String, AttributeValue> level2Map = new HashMap<>(putItem.get("level2").m());
@@ -1447,6 +1450,49 @@
         assertThat(writtenNestedList.get(1), is(childDocumentBeforeWrite));
     }
 
+    @Test
+    public void beforeWrite_listWithCustomConverter_whenElementTypeNotAnnotated_thenTimestampSetAndListUnchanged() {
+        String expectedWrittenInstant = MOCKED_INSTANT_NOW.toString();
+        TableSchema<BeanWithCustomConvertedList> schema = BeanTableSchema.create(BeanWithCustomConvertedList.class);
+        BeanWithCustomConvertedList record = new BeanWithCustomConvertedList()
+            .setId("1")
+            .setCustomItems(Arrays.asList(
+                new CustomConvertedPojo("a", 1),
+                new CustomConvertedPojo("b", 2)));
+
+        Map<String, AttributeValue> putItem = new HashMap<>(schema.itemToMap(record, false));
+        AttributeValue originalList = putItem.get("customItems");
+
+        WriteModification modification = invokeBeforeWriteForPutItem(putItem, schema);
+        Map<String, AttributeValue> transformed = modification.transformedItem();
+
+        assertThat(transformed, is(notNullValue()));
+        assertThat(transformed.get("time").s(), is(expectedWrittenInstant));
+        assertThat(transformed.get("customItems"), is(originalList));
+    }
+
+    @Test
+    public void beforeWrite_mapWithCustomConverter_whenValueTypeNotAnnotated_thenTimestampSetAndMapUnchanged() {
+        String expectedWrittenInstant = MOCKED_INSTANT_NOW.toString();
+        TableSchema<BeanWithCustomConvertedMap> schema = BeanTableSchema.create(BeanWithCustomConvertedMap.class);
+        Map<String, CustomConvertedPojo> pojoMap = new HashMap<>();
+        pojoMap.put("first", new CustomConvertedPojo("x", 10));
+        pojoMap.put("second", new CustomConvertedPojo("y", 20));
+        BeanWithCustomConvertedMap record = new BeanWithCustomConvertedMap()
+            .setId("1")
+            .setCustomMap(pojoMap);
+
+        Map<String, AttributeValue> putItem = new HashMap<>(schema.itemToMap(record, false));
+        AttributeValue originalMap = putItem.get("customMap");
+
+        WriteModification modification = invokeBeforeWriteForPutItem(putItem, schema);
+        Map<String, AttributeValue> transformed = modification.transformedItem();
+
+        assertThat(transformed, is(notNullValue()));
+        assertThat(transformed.get("time").s(), is(expectedWrittenInstant));
+        assertThat(transformed.get("customMap"), is(originalMap));
+    }
+
     private <T> WriteModification invokeBeforeWriteForPutItem(Map<String, AttributeValue> itemAttributes,
                                                             TableSchema<T> tableSchema) {
         return invokeBeforeWriteForPutItem(itemAttributes, tableSchema.tableMetadata(), tableSchema);

services-custom/dynamodb-enhanced/src/test/java/software/amazon/awssdk/enhanced/dynamodb/functionaltests/models/AutogeneratedTimestampTestModels.java

@@ -19,18 +19,25 @@
 import static software.amazon.awssdk.enhanced.dynamodb.mapper.StaticAttributeTags.primaryPartitionKey;
 
 import java.time.Instant;
+import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
+import software.amazon.awssdk.enhanced.dynamodb.AttributeConverter;
+import software.amazon.awssdk.enhanced.dynamodb.AttributeValueType;
 import software.amazon.awssdk.enhanced.dynamodb.EnhancedType;
 import software.amazon.awssdk.enhanced.dynamodb.TableSchema;
 import software.amazon.awssdk.enhanced.dynamodb.extensions.annotations.DynamoDbAutoGeneratedTimestampAttribute;
 import software.amazon.awssdk.enhanced.dynamodb.mapper.StaticImmutableTableSchema;
 import software.amazon.awssdk.enhanced.dynamodb.mapper.StaticTableSchema;
 import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbBean;
+import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbConvertedBy;
 import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbImmutable;
 import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbPartitionKey;
+import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
 
 /**
  * Test models specifically designed for auto-generated timestamp functionality testing. These models focus on the "time"
@@ -730,7 +737,7 @@
     @DynamoDbBean
     public static class BeanWithInvalidRootAttributeName {
         private String id;
         private Instant attr_NESTED_ATTR_UPDATE_;
 
         @DynamoDbPartitionKey
         public String getId() {
@@ -747,7 +754,7 @@
             return attr_NESTED_ATTR_UPDATE_;
         }
 
         public BeanWithInvalidRootAttributeName setAttr_NESTED_ATTR_UPDATE_(Instant attr_NESTED_ATTR_UPDATE_) {
             this.attr_NESTED_ATTR_UPDATE_ = attr_NESTED_ATTR_UPDATE_;
             return this;
         }
@@ -785,7 +792,7 @@
         public static class BeanWithInvalidNestedAttributeNameChild {
             private String id;
             private BeanWithInvalidNestedAttributeNameChild nestedChildAttribute;
             private Instant childAttr_NESTED_ATTR_UPDATE_;
 
             @DynamoDbPartitionKey
             public String getId() {
@@ -811,10 +818,233 @@
                 return childAttr_NESTED_ATTR_UPDATE_;
             }
 
             public BeanWithInvalidNestedAttributeNameChild setAttr_NESTED_ATTR_UPDATE_(Instant attr_NESTED_ATTR_UPDATE_) {
                 this.childAttr_NESTED_ATTR_UPDATE_ = attr_NESTED_ATTR_UPDATE_;
                 return this;
             }
         }
     }
+
+    /**
+     * Plain POJO with no DynamoDB annotations. Serialization is handled entirely by
+     * {@link CustomConvertedPojoListConverter}.
+     */
+    public static class CustomConvertedPojo {
+        private String label;
+        private int count;
+
+        public CustomConvertedPojo() {
+        }
+
+        public CustomConvertedPojo(String label, int count) {
+            this.label = label;
+            this.count = count;
+        }
+
+        public String getLabel() {
+            return label;
+        }
+
+        public void setLabel(String label) {
+            this.label = label;
+        }
+
+        public int getCount() {
+            return count;
+        }
+
+        public void setCount(int count) {
+            this.count = count;
+        }
+    }
+
+    /**
+     * Custom converter for {@code List<CustomConvertedPojo>}. The SDK should not attempt to resolve a
+     * {@link TableSchema} for {@link CustomConvertedPojo} when this converter is present.
+     */
+    public static class CustomConvertedPojoListConverter implements AttributeConverter<List<CustomConvertedPojo>> {
+
+        @Override
+        public AttributeValue transformFrom(List<CustomConvertedPojo> input) {
+            if (input == null) {
+                return AttributeValue.builder().nul(true).build();
+            }
+            List<AttributeValue> items = input.stream()
+                .map(pojo -> {
+                    Map<String, AttributeValue> map = new HashMap<>();
+                    map.put("label", AttributeValue.builder().s(pojo.getLabel()).build());
+                    map.put("count", AttributeValue.builder().n(String.valueOf(pojo.getCount())).build());
+                    return AttributeValue.builder().m(map).build();
+                })
+                .collect(Collectors.toList());
+            return AttributeValue.builder().l(items).build();
+        }
+
+        @Override
+        public List<CustomConvertedPojo> transformTo(AttributeValue input) {
+            if (input.l() == null) {
+                return new ArrayList<>();
+            }
+            return input.l().stream()
+                .map(av -> {
+                    Map<String, AttributeValue> m = av.m();
+                    CustomConvertedPojo pojo = new CustomConvertedPojo();
+                    if (m.containsKey("label")) {
+                        pojo.setLabel(m.get("label").s());
+                    }
+                    if (m.containsKey("count")) {
+                        pojo.setCount(Integer.parseInt(m.get("count").n()));
+                    }
+                    return pojo;
+                })
+                .collect(Collectors.toList());
+        }
+
+        @Override
+        public EnhancedType<List<CustomConvertedPojo>> type() {
+            return EnhancedType.listOf(CustomConvertedPojo.class);
+        }
+
+        @Override
+        public AttributeValueType attributeValueType() {
+            return AttributeValueType.L;
+        }
+    }
+
+    /**
+     * Bean that combines {@code @DynamoDbAutoGeneratedTimestampAttribute} with a
+     * {@code @DynamoDbConvertedBy} list whose element type ({@link CustomConvertedPojo}) has no DynamoDB
+     * annotations. Reproduces the regression described in GitHub issue #6852.
+     */
+    @DynamoDbBean
+    public static class BeanWithCustomConvertedList {
+        private String id;
+        private Instant time;
+        private List<CustomConvertedPojo> customItems;
+
+        @DynamoDbPartitionKey
+        public String getId() {
+            return id;
+        }
+
+        public BeanWithCustomConvertedList setId(String id) {
+            this.id = id;
+            return this;
+        }
+
+        @DynamoDbAutoGeneratedTimestampAttribute
+        public Instant getTime() {
+            return time;
+        }
+
+        public BeanWithCustomConvertedList setTime(Instant time) {
+            this.time = time;
+            return this;
+        }
+
+        @DynamoDbConvertedBy(CustomConvertedPojoListConverter.class)
+        public List<CustomConvertedPojo> getCustomItems() {
+            return customItems;
+        }
+
+        public BeanWithCustomConvertedList setCustomItems(List<CustomConvertedPojo> customItems) {
+            this.customItems = customItems;
+            return this;
+        }
+    }
+
+    /**
+     * Custom converter for {@code Map<String, CustomConvertedPojo>}. Serializes the map as a DynamoDB M attribute
+     * whose values are themselves maps. The SDK should not attempt to resolve a {@link TableSchema} for
+     * {@link CustomConvertedPojo} when this converter is present.
+     */
+    public static class CustomConvertedPojoMapConverter implements AttributeConverter<Map<String, CustomConvertedPojo>> {
+
+        @Override
+        public AttributeValue transformFrom(Map<String, CustomConvertedPojo> input) {
+            if (input == null) {
+                return AttributeValue.builder().nul(true).build();
+            }
+            Map<String, AttributeValue> map = new HashMap<>();
+            for (Map.Entry<String, CustomConvertedPojo> entry : input.entrySet()) {
+                Map<String, AttributeValue> inner = new HashMap<>();
+                inner.put("label", AttributeValue.builder().s(entry.getValue().getLabel()).build());
+                inner.put("count", AttributeValue.builder().n(String.valueOf(entry.getValue().getCount())).build());
+                map.put(entry.getKey(), AttributeValue.builder().m(inner).build());
+            }
+            return AttributeValue.builder().m(map).build();
+        }
+
+        @Override
+        public Map<String, CustomConvertedPojo> transformTo(AttributeValue input) {
+            if (input.m() == null) {
+                return new HashMap<>();
+            }
+            Map<String, CustomConvertedPojo> result = new HashMap<>();
+            for (Map.Entry<String, AttributeValue> entry : input.m().entrySet()) {
+                Map<String, AttributeValue> m = entry.getValue().m();
+                CustomConvertedPojo pojo = new CustomConvertedPojo();
+                if (m.containsKey("label")) {
+                    pojo.setLabel(m.get("label").s());
+                }
+                if (m.containsKey("count")) {
+                    pojo.setCount(Integer.parseInt(m.get("count").n()));
+                }
+                result.put(entry.getKey(), pojo);
+            }
+            return result;
+        }
+
+        @Override
+        public EnhancedType<Map<String, CustomConvertedPojo>> type() {
+            return EnhancedType.mapOf(String.class, CustomConvertedPojo.class);
+        }
+
+        @Override
+        public AttributeValueType attributeValueType() {
+            return AttributeValueType.M;
+        }
+    }
+
+    /**
+     * Bean that combines {@code @DynamoDbAutoGeneratedTimestampAttribute} with a
+     * {@code @DynamoDbConvertedBy} map whose value type ({@link CustomConvertedPojo}) has no DynamoDB
+     * annotations. Verifies the map path is safe alongside the list regression test.
+     */
+    @DynamoDbBean
+    public static class BeanWithCustomConvertedMap {
+        private String id;
+        private Instant time;
+        private Map<String, CustomConvertedPojo> customMap;
+
+        @DynamoDbPartitionKey
+        public String getId() {
+            return id;
+        }
+
+        public BeanWithCustomConvertedMap setId(String id) {
+            this.id = id;
+            return this;
+        }
+
+        @DynamoDbAutoGeneratedTimestampAttribute
+        public Instant getTime() {
+            return time;
+        }
+
+        public BeanWithCustomConvertedMap setTime(Instant time) {
+            this.time = time;
+            return this;
+        }
+
+        @DynamoDbConvertedBy(CustomConvertedPojoMapConverter.class)
+        public Map<String, CustomConvertedPojo> getCustomMap() {
+            return customMap;
+        }
+
+        public BeanWithCustomConvertedMap setCustomMap(Map<String, CustomConvertedPojo> customMap) {
+            this.customMap = customMap;
+            return this;
+        }
+    }
 }