DATAREST-957 - Improved PUT handling for transient properties not backed by a field.

When copying the transient properties of an aggregate, we now try field based access first and fall back to accessor based copying in case both a setter and getter are exposed on the type.

Previously we always expected a field to be present which doesn't necessarily has to be the case.

Related ticket: DATAREST-986.

Author: odrotbohm

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/json/DomainObjectReader.java

@@ -204,11 +204,23 @@ public void doWithPersistentProperty(PersistentProperty<?> property) {
 	 */
 	private static void copyRemainingProperties(MappedProperties properties, Object source, Object target) {
 
-		PropertyAccessor sourceAccessor = PropertyAccessorFactory.forDirectFieldAccess(source);
-		PropertyAccessor targetAccessor = PropertyAccessorFactory.forDirectFieldAccess(target);
+		PropertyAccessor sourceFieldAccessor = PropertyAccessorFactory.forDirectFieldAccess(source);
+		PropertyAccessor sourcePropertyAccessor = PropertyAccessorFactory.forBeanPropertyAccess(source);
+		PropertyAccessor targetFieldAccessor = PropertyAccessorFactory.forDirectFieldAccess(target);
+		PropertyAccessor targetPropertyAccessor = PropertyAccessorFactory.forBeanPropertyAccess(target);
 
 		for (String property : properties.getSpringDataUnmappedProperties()) {
-			targetAccessor.setPropertyValue(property, sourceAccessor.getPropertyValue(property));
+
+			// If there's a field we can just copy it.
+			if (targetFieldAccessor.isWritableProperty(property)) {
+				targetFieldAccessor.setPropertyValue(property, sourceFieldAccessor.getPropertyValue(property));
+				continue;
+			}
+
+			// Otherwise only copy if there's both a getter and setter.
+			if (targetPropertyAccessor.isWritableProperty(property) && sourcePropertyAccessor.isReadableProperty(property)) {
+				targetPropertyAccessor.setPropertyValue(property, sourcePropertyAccessor.getPropertyValue(property));
+			}
 		}
 	}
 

spring-data-rest-webmvc/src/test/java/org/springframework/data/rest/webmvc/json/DomainObjectReaderUnitTests.java

@@ -92,6 +92,7 @@ public void setUp() {
 		mappingContext.getPersistentEntity(Outer.class);
 		mappingContext.getPersistentEntity(Parent.class);
 		mappingContext.getPersistentEntity(Product.class);
+		mappingContext.getPersistentEntity(TransientReadOnlyProperty.class);
 		mappingContext.afterPropertiesSet();
 
 		PersistentEntities entities = new PersistentEntities(Collections.singleton(mappingContext));
@@ -441,6 +442,15 @@ public void readsComplexMap() throws Exception {
 		assertThat(result.map.get(Locale.GERMAN), is(new LocalizedValue("schlussendlich")));
 	}
 
+	@Test // DATAREST-987
+	public void handlesTransientPropertyWithoutFieldProperly() throws Exception {
+
+		ObjectMapper mapper = new ObjectMapper();
+		JsonNode node = mapper.readTree("{ \"name\" : \"Foo\" }");
+
+		reader.readPut((ObjectNode) node, new TransientReadOnlyProperty(), mapper);
+	}
+
 	@SuppressWarnings("unchecked")
 	private static <T> T as(Object source, Class<T> type) {
 
@@ -564,4 +574,15 @@ static class Product {
 	static class LocalizedValue {
 		String value;
 	}
+
+	@JsonAutoDetect(getterVisibility = Visibility.ANY)
+	static class TransientReadOnlyProperty {
+
+		@Transient
+		public String getName() {
+			return null;
+		}
+
+		public void setName(String name) {}
+	}
 }