Fix mapping URIs to @JsonProperty annotated associations

Normally, when creating and updating (POST/PUT) an entity via the REST endpoints, you can use the URL of the relation target. (e.g.: send `{"package": "/packages/1"}` when `package` is a JPA `@OneToOne` relation).

Now this also takes into account when the JPA relation is annotated with `@JsonProperty` to change the serialized name.

Add unit tests for linkable associations.

Issue: #2165

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/json/PersistentEntityJackson2Module.java

@@ -24,6 +24,7 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Objects;
 import java.util.Optional;
 
 import org.slf4j.Logger;
@@ -82,6 +83,8 @@ import com.fasterxml.jackson.databind.deser.std.CollectionDeserializer;
 import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
 import com.fasterxml.jackson.databind.deser.std.StdScalarDeserializer;
 import com.fasterxml.jackson.databind.deser.std.StdValueInstantiator;
+import com.fasterxml.jackson.databind.introspect.AnnotatedField;
+import com.fasterxml.jackson.databind.introspect.BeanPropertyDefinition;
 import com.fasterxml.jackson.databind.jsontype.TypeDeserializer;
 import com.fasterxml.jackson.databind.jsontype.TypeSerializer;
 import com.fasterxml.jackson.databind.module.SimpleModule;
@@ -410,6 +413,7 @@ public class PersistentEntityJackson2Module extends SimpleModule {
 	 * non-optional associations can be populated on resource creation.
 	 *
 	 * @author Oliver Gierke
+	 * @author Lars Vierbergen
 	 */
 	public static class AssociationUriResolvingDeserializerModifier extends BeanDeserializerModifier {
 
@@ -444,7 +448,18 @@ public class PersistentEntityJackson2Module extends SimpleModule {
 				while (properties.hasNext()) {
 
 					SettableBeanProperty property = properties.next();
-					PersistentProperty<?> persistentProperty = entity.getPersistentProperty(property.getName());
+					// To find the PersistentProperty name in case there is a @JsonProperty annotation
+					// on the field. Both BeanPropertyDefinition#getName() and BeanPropertyDefinition#getInternalName()
+					// don't return the actual name of the field, so we look up the AnnotatedField itself to retrieve
+					// the real name from, so it can be used for PersistentProperty lookup
+					String persistentPropertyName = beanDesc.findProperties().stream()
+							.filter(propertyDefinition -> property.getName().equals(propertyDefinition.getName()))
+							.map(BeanPropertyDefinition::getField).filter(Objects::nonNull).map(AnnotatedField::getName).findFirst()
+							// Fall back to the JSON name in case we can't find a BeanPropertyDefinition,
+							// so things can be mapped by convention in case they are immutable objects and are
+							// using constructor injection
+							.orElse(property.getName());
+					PersistentProperty<?> persistentProperty = entity.getPersistentProperty(persistentPropertyName);
 
 					if (persistentProperty == null) {
 						continue;

spring-data-rest-webmvc/src/test/java/org/springframework/data/rest/webmvc/json/PersistentEntityJackson2ModuleUnitTests.java

@@ -19,6 +19,7 @@ import static org.assertj.core.api.Assertions.*;
 import static org.mockito.ArgumentMatchers.*;
 import static org.mockito.Mockito.*;
 
+import lombok.AccessLevel;
 import lombok.Data;
 import lombok.Getter;
 
@@ -96,6 +97,7 @@ class PersistentEntityJackson2ModuleUnitTests {
 
 		KeyValueMappingContext<?, ?> mappingContext = new KeyValueMappingContext<>();
 		mappingContext.getPersistentEntity(Sample.class);
+		mappingContext.getPersistentEntity(Package.class);
 		mappingContext.getPersistentEntity(SampleWithAdditionalGetters.class);
 		mappingContext.getPersistentEntity(PersistentEntityJackson2ModuleUnitTests.PetOwner.class);
 		mappingContext.getPersistentEntity(Immutable.class);
@@ -157,6 +159,41 @@ class PersistentEntityJackson2ModuleUnitTests {
 		assertThat(petOwner.getPet()).isNotNull();
 	}
 
+	@Test
+	void allowsUrlsForLinkableAssociation() throws Exception {
+
+		when(converter.convert(UriTemplate.of("/homes/1").expand(), TypeDescriptor.valueOf(URI.class),
+				TypeDescriptor.valueOf(Home.class))).thenReturn(new Home());
+
+		PersistentProperty<?> property = persistentEntities.getRequiredPersistentEntity(PetOwner.class)
+				.getRequiredPersistentProperty("home");
+
+		when(associations.isLinkableAssociation(property)).thenReturn(true);
+
+		PetOwner petOwner = mapper.readValue("{\"home\": \"/homes/1\" }", PetOwner.class);
+
+		assertThat(petOwner).isNotNull();
+		assertThat(petOwner.getHome()).isInstanceOf(Home.class);
+	}
+
+	@Test
+	void allowsUrlsForRenamedLinkableAssociation() throws IOException {
+
+		when(converter.convert(UriTemplate.of("/packages/1").expand(), TypeDescriptor.valueOf(URI.class),
+				TypeDescriptor.valueOf(Package.class))).thenReturn(new Package());
+
+		PersistentProperty<?> property = persistentEntities.getRequiredPersistentEntity(PetOwner.class)
+				.getRequiredPersistentProperty("_package");
+
+		when(associations.isLinkableAssociation(property)).thenReturn(true);
+
+		PetOwner petOwner = mapper.readValue("{\"package\":\"/packages/1\"}", PetOwner.class);
+
+		assertThat(petOwner).isNotNull();
+		assertThat(petOwner.getPackage()).isNotNull();
+	}
+
+
 	@Test // DATAREST-1321
 	void allowsNumericIdsForLookupTypes() throws Exception {
 
@@ -260,8 +297,17 @@ class PersistentEntityJackson2ModuleUnitTests {
 
 		Pet pet;
 		Home home;
+
+		@Getter(value = AccessLevel.NONE)
+		@JsonProperty("package") Package _package;
+
+		public Package getPackage() {
+			return _package;
+		}
 	}
 
+	static class Package {}
+
 	@JsonTypeInfo(include = JsonTypeInfo.As.PROPERTY, use = JsonTypeInfo.Id.MINIMAL_CLASS)
 	static class Pet {}