Support mutually recursive DynamoDB bean schemas

Author: afarber

.changes/next-release/bugfix-AmazonDynamoDB-c60c54b.json

@@ -0,0 +1,6 @@
+{
+    "type": "bugfix",
+    "category": "Amazon DynamoDB",
+    "description": "Fix `TableSchema.fromBean` for mutually recursive `@DynamoDbBean` classes. ([#6110](https://github.com/aws/aws-sdk-java-v2/issues/6110))",
+    "contributor": "afarber"
+}

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/mapper/BeanTableSchema.java

@@ -192,8 +192,8 @@ private static <T> BeanTableSchema<T> create(BeanTableSchemaParams<T> params, Me
         return newTableSchema;
     }
 
-    // Called when creating an immutable TableSchema recursively. Utilizes the MetaTableSchema cache to stop infinite
-    // recursion
+    // Called when creating a bean TableSchema recursively. Utilizes the MetaTableSchema cache to stop infinite
+    // recursion for self-referencing and mutually recursive schemas.
     static <T> TableSchema<T> recursiveCreate(Class<T> beanClass, MethodHandles.Lookup lookup,
                                               MetaTableSchemaCache metaTableSchemaCache) {
         Optional<MetaTableSchema<T>> metaTableSchema = metaTableSchemaCache.get(beanClass);
@@ -211,7 +211,8 @@ static <T> TableSchema<T> recursiveCreate(Class<T> beanClass, MethodHandles.Look
         }
 
         // Otherwise: cache doesn't know about this class; create a new one from scratch
-        return create(BeanTableSchemaParams.builder(beanClass).lookup(lookup).build());
+        return create(BeanTableSchemaParams.builder(beanClass).lookup(lookup).build(), metaTableSchemaCache,
+                      ExecutionContext.ROOT);
 
     }
 
@@ -603,4 +604,3 @@ static void clearSchemaCache() {
         BEAN_TABLE_SCHEMA_CACHE.clear();
     }
 }
-

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

@@ -23,9 +23,28 @@
 import software.amazon.awssdk.enhanced.dynamodb.TableSchema;
 import software.amazon.awssdk.enhanced.dynamodb.functionaltests.models.RecursiveRecordBean;
 import software.amazon.awssdk.enhanced.dynamodb.functionaltests.models.RecursiveRecordImmutable;
+import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbBean;
 import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
 
 public class BeanTableSchemaRecursiveTest {
+    @Test
+    public void transitiveRecursiveBean_document() {
+        TableSchema<TransitiveRecursiveParent> tableSchema = TableSchema.fromBean(TransitiveRecursiveParent.class);
+
+        TransitiveRecursiveChild child = new TransitiveRecursiveChild();
+        child.setName("child");
+
+        TransitiveRecursiveParent parent = new TransitiveRecursiveParent();
+        parent.setName("parent");
+        parent.setChild(child);
+
+        TransitiveRecursiveParent roundTrip = tableSchema.mapToItem(tableSchema.itemToMap(parent, true));
+
+        assertThat(roundTrip.getName()).isEqualTo("parent");
+        assertThat(roundTrip.getChild().getName()).isEqualTo("child");
+        assertThat(roundTrip.getChild().getParent()).isNull();
+    }
+
     @Test
     public void recursiveRecord_document() {
         TableSchema<RecursiveRecordBean> tableSchema = TableSchema.fromClass(RecursiveRecordBean.class);
@@ -89,4 +108,48 @@ public void recursiveRecord_list() {
             });
         });
     }
+
+    @DynamoDbBean
+    public static class TransitiveRecursiveParent {
+        private String name;
+        private TransitiveRecursiveChild child;
+
+        public String getName() {
+            return name;
+        }
+
+        public void setName(String name) {
+            this.name = name;
+        }
+
+        public TransitiveRecursiveChild getChild() {
+            return child;
+        }
+
+        public void setChild(TransitiveRecursiveChild child) {
+            this.child = child;
+        }
+    }
+
+    @DynamoDbBean
+    public static class TransitiveRecursiveChild {
+        private String name;
+        private TransitiveRecursiveParent parent;
+
+        public String getName() {
+            return name;
+        }
+
+        public void setName(String name) {
+            this.name = name;
+        }
+
+        public TransitiveRecursiveParent getParent() {
+            return parent;
+        }
+
+        public void setParent(TransitiveRecursiveParent parent) {
+            this.parent = parent;
+        }
+    }
 }