DATAREST-835 - Search resources returning a single resource now get and consider ETag and Last-Modified headers.

We now interpret If-None-Match and If-Modified-Since headers on requests to resources backed by query methods returning a single instance only. This allows clients to optimize GET requests to those resources to save bandwidth.

spring-data-rest-tests/spring-data-rest-tests-jpa/src/test/java/org/springframework/data/rest/webmvc/RepositoryEntityControllerIntegrationTests.java

@@ -42,12 +42,12 @@ import org.springframework.data.rest.webmvc.support.DefaultedPageable;
 import org.springframework.data.rest.webmvc.support.ETag;
 import org.springframework.hateoas.Resource;
 import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.transaction.annotation.Transactional;
-import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.web.HttpRequestMethodNotSupportedException;
 
 /**
@@ -273,7 +273,7 @@ public class RepositoryEntityControllerIntegrationTests extends AbstractControll
 		Mockito.when(assembler.toFullResource(Mockito.any(Object.class))).thenReturn(resource);
 
 		ResponseEntity<Resource<?>> entity = controller.getItemResource(getResourceInformation(Address.class), address.id,
-				assembler, new LinkedMultiValueMap<String, String>());
+				assembler, new HttpHeaders());
 
 		assertThat(entity.getHeaders().getETag(), is(notNullValue()));
 	}

spring-data-rest-tests/spring-data-rest-tests-jpa/src/test/java/org/springframework/data/rest/webmvc/RepositorySearchControllerIntegrationTests.java

@@ -39,6 +39,7 @@ import org.springframework.hateoas.PagedResources;
 import org.springframework.hateoas.ResourceSupport;
 import org.springframework.hateoas.Resources;
 import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.ResponseEntity;
 import org.springframework.test.context.ContextConfiguration;
@@ -100,8 +101,8 @@ public class RepositorySearchControllerIntegrationTests extends AbstractControll
 		MultiValueMap<String, Object> parameters = new LinkedMultiValueMap<String, Object>(1);
 		parameters.add("firstname", "John");
 
-		ResponseEntity<Object> response = controller.executeSearch(resourceInformation, parameters, "firstname", PAGEABLE,
-				null, assembler);
+		ResponseEntity<?> response = controller.executeSearch(resourceInformation, parameters, "firstname", PAGEABLE, null,
+				assembler, new HttpHeaders());
 
 		ResourceTester tester = ResourceTester.of(response.getBody());
 		PagedResources<Object> pagedResources = tester.assertIsPage();
@@ -190,8 +191,8 @@ public class RepositorySearchControllerIntegrationTests extends AbstractControll
 
 		RootResourceInformation resourceInformation = getResourceInformation(Book.class);
 
-		ResponseEntity<Object> result = controller.executeSearch(resourceInformation, parameters, "findByAuthorsContains",
-				PAGEABLE, null, assembler);
+		ResponseEntity<?> result = controller.executeSearch(resourceInformation, parameters, "findByAuthorsContains",
+				PAGEABLE, null, assembler, new HttpHeaders());
 
 		assertThat(result.getBody(), is(instanceOf(Resources.class)));
 	}

spring-data-rest-tests/spring-data-rest-tests-mongodb/src/main/java/org/springframework/data/rest/tests/mongodb/Profile.java

@@ -21,6 +21,7 @@ import java.util.Map;
 
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.LastModifiedDate;
+import org.springframework.data.annotation.Version;
 import org.springframework.data.mongodb.core.mapping.Document;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
@@ -36,6 +37,7 @@ public class Profile {
 	private Long person;
 	private @JsonProperty(required = true) String type;
 	private @LastModifiedDate Date lastModifiedDate;
+	private @Version Long version;
 	private @JsonProperty("renamed") String aliased;
 	private Map<String, String> metadata = new HashMap<String, String>();
 

spring-data-rest-tests/spring-data-rest-tests-mongodb/src/test/java/org/springframework/data/rest/tests/mongodb/MongoWebTests.java

@@ -343,4 +343,34 @@ public class MongoWebTests extends CommonWebTests {
 
 		mvc.perform(get(href)).andExpect(status().isOk());
 	}
+
+	/**
+	 * @see DATAREST-835
+	 */
+	@Test
+	public void exposesETagHeaderForSearchResourceYieldingItemResource() throws Exception {
+
+		Link link = client.discoverUnique("profiles", "search", "findById");
+
+		Profile profile = repository.findAll().iterator().next();
+
+		mvc.perform(get(link.expand(profile.getId()).getHref()))//
+				.andExpect(header().string("ETag", is("\"0\"")))//
+				.andExpect(header().string("Last-Modified", is(notNullValue())));
+	}
+
+	/**
+	 * @see DATAREST-835
+	 */
+	@Test
+	public void doesNotAddETagHeaderForCollectionQueryResource() throws Exception {
+
+		Link link = client.discoverUnique("profiles", "search", "findByType");
+
+		Profile profile = repository.findAll().iterator().next();
+
+		mvc.perform(get(link.expand(profile.getType()).getHref()))//
+				.andExpect(header().string("ETag", is(nullValue())))//
+				.andExpect(header().string("Last-Modified", is(nullValue())));
+	}
 }