issue #5039 - added support for fluent setters in dynamodb enhanced client

Author: iulianbudau

.changes/next-release/feature-AmazonDynamoDBEnhancedClient-2d32cd6.json

@@ -0,0 +1,6 @@
+{
+    "type": "feature",
+    "category": "Amazon DynamoDB Enhanced Client",
+    "contributor": "",
+    "description": "Added support for fluent setters in bean descriptors when the default setter is missing."
+}

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

@@ -182,6 +182,7 @@ private static <T> StaticTableSchema<T> createStaticTableSchema(Class<T> beanCla
 
         try {
             beanInfo = Introspector.getBeanInfo(beanClass);
+            enhanceDescriptorsWithFluentSetters(beanClass, beanInfo);
         } catch (IntrospectionException e) {
             throw new IllegalArgumentException(e);
         }
@@ -225,6 +226,34 @@ private static <T> StaticTableSchema<T> createStaticTableSchema(Class<T> beanCla
         return builder.build();
     }
 
+    // Enhance beanInfo descriptors with fluent setter when the default set method is absent
+    private static <T> void enhanceDescriptorsWithFluentSetters(Class<T> beanClass, BeanInfo beanInfo) {
+        Arrays.stream(beanInfo.getPropertyDescriptors())
+              .filter(descriptor -> descriptor.getWriteMethod() == null)
+              .forEach(descriptor -> findFluentSetter(beanClass, descriptor.getName())
+                  .ifPresent(method -> {
+                      try {
+                          descriptor.setWriteMethod(method);
+                      } catch (IntrospectionException e) {
+                          throw new RuntimeException("Failed to set write method for " + descriptor.getName(), e);
+                      }
+                  }));
+    }
+
+    private static Optional<Method> findFluentSetter(Class<?> beanClass, String propertyName) {
+        String setterName = "set" + capitalize(propertyName);
+
+        return Arrays.stream(beanClass.getMethods())
+                     .filter(m -> m.getName().equals(setterName)
+                                  && m.getParameterCount() == 1
+                                  && m.getReturnType().equals(beanClass))
+                     .findFirst();
+    }
+
+    private static String capitalize(String name) {
+        return Character.toUpperCase(name.charAt(0)) + name.substring(1);
+    }
+
     private static AttributeConfiguration resolveAttributeConfiguration(PropertyDescriptor propertyDescriptor) {
         boolean shouldPreserveEmptyObject = getPropertyAnnotation(propertyDescriptor,
                                                                   DynamoDbPreserveEmptyObject.class) != null;

services-custom/dynamodb-enhanced/src/test/java/software/amazon/awssdk/enhanced/dynamodb/mapper/BeanTableSchemaTest.java

@@ -55,6 +55,7 @@
 import software.amazon.awssdk.enhanced.dynamodb.mapper.testbeans.ExtendedBean;
 import software.amazon.awssdk.enhanced.dynamodb.mapper.testbeans.FlattenedBeanBean;
 import software.amazon.awssdk.enhanced.dynamodb.mapper.testbeans.FlattenedImmutableBean;
+import software.amazon.awssdk.enhanced.dynamodb.mapper.testbeans.FluentSetterBean;
 import software.amazon.awssdk.enhanced.dynamodb.mapper.testbeans.IgnoredAttributeBean;
 import software.amazon.awssdk.enhanced.dynamodb.mapper.testbeans.InvalidBean;
 import software.amazon.awssdk.enhanced.dynamodb.mapper.testbeans.ListBean;
@@ -1160,4 +1161,22 @@ public void emptyConverterProviderList_correct_whenAttributeConvertersAreSupplie
         assertThat(reverse.getId(), is(equalTo("id-value-custom")));
         assertThat(reverse.getIntegerAttribute(), is(equalTo(133)));
     }
+
+    @Test
+    public void fluentSetterBean_correctlyMapsBeanAttributes() {
+        BeanTableSchema<FluentSetterBean> beanTableSchema =
+            BeanTableSchema.create(FluentSetterBean.class);
+
+        FluentSetterBean fluentSetterBean = new FluentSetterBean()
+            .setAttribute1(1)
+            .setAttribute2("testAttribute2")
+            .setAttribute3("testAttribute3");
+
+        Map<String, AttributeValue> itemMap = beanTableSchema.itemToMap(fluentSetterBean, false);
+
+        assertThat(itemMap.size(), is(3));
+        assertThat(itemMap, hasEntry("attribute1", numberValue(1)));
+        assertThat(itemMap, hasEntry("attribute2", stringValue("testAttribute2")));
+        assertThat(itemMap, hasEntry("attribute3", stringValue("testAttribute3")));
+    }
 }

services-custom/dynamodb-enhanced/src/test/java/software/amazon/awssdk/enhanced/dynamodb/mapper/testbeans/FluentSetterBean.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.awssdk.enhanced.dynamodb.mapper.testbeans;
+
+import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbBean;
+import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbPartitionKey;
+import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbSortKey;
+
+@DynamoDbBean
+public class FluentSetterBean {
+
+    private Integer attribute1;
+    private String attribute2;
+    private String attribute3;
+
+    @DynamoDbPartitionKey
+    public Integer getAttribute1() {
+        return attribute1;
+    }
+
+    public FluentSetterBean setAttribute1(Integer attribute1) {
+        this.attribute1 = attribute1;
+        return this;
+    }
+
+    @DynamoDbSortKey
+    public String getAttribute2() {
+        return attribute2;
+    }
+
+    public FluentSetterBean setAttribute2(String attribute2) {
+        this.attribute2 = attribute2;
+        return this;
+    }
+
+    public String getAttribute3() {
+        return attribute3;
+    }
+
+    public FluentSetterBean setAttribute3(String attribute3) {
+        this.attribute3 = attribute3;
+        return this;
+    }
+}