DATAREDIS-547 - Polishing.

Return empty list if offset is greater than the available data set. Update supported keywords in reference docs.

Original pull request: #216.

Author: mp911de

src/main/asciidoc/reference/redis-repositories.adoc

@@ -540,6 +540,7 @@ Here's an overview of the keywords supported for Redis and what a method contain
 |`And`|`findByLastnameAndFirstname`|`SINTER …:firstname:rand …:lastname:al’thor`
 |`Or`|`findByLastnameOrFirstname`|`SUNION …:firstname:rand …:lastname:al’thor`
 |`Is,Equals`|`findByFirstname`,`findByFirstnameIs`,`findByFirstnameEquals`|`SINTER …:firstname:rand`
+|`Top,First`|`findFirst10ByFirstname`,`findTop5ByFirstname`|
 |===============
 ====
 

src/main/java/org/springframework/data/redis/core/RedisKeyValueAdapter.java

@@ -17,6 +17,7 @@
 
 import java.io.Serializable;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -357,6 +358,11 @@ public Set<byte[]> doInRedis(RedisConnection connection) throws DataAccessExcept
 
 		List<byte[]> keys = new ArrayList<byte[]>(ids);
 
+
+		if (keys.isEmpty() || keys.size() < offset) {
+			return Collections.emptyList();
+		}
+
 		offset = Math.max(0, offset);
 		if (offset >= 0 && rows > 0) {
 			keys = keys.subList(offset, Math.min(offset + rows, keys.size()));

src/main/java/org/springframework/data/redis/core/RedisQueryEngine.java

@@ -102,7 +102,7 @@ public Map<byte[], Map<byte[], byte[]>> doInRedis(RedisConnection connection) th
 
 				final Map<byte[], Map<byte[], byte[]>> rawData = new LinkedHashMap<byte[], Map<byte[], byte[]>>();
 
-				if (allKeys.size() == 0 || allKeys.size() < offset) {
+				if (allKeys.isEmpty() || allKeys.size() < offset) {
 					return Collections.emptyMap();
 				}
 

src/test/java/org/springframework/data/redis/repository/RedisRepositoryIntegrationTestBase.java

@@ -47,6 +47,7 @@
  * Base for testing Redis repository support in different configurations.
  * 
  * @author Christoph Strobl
+ * @author Mark Paluch
  */
 public abstract class RedisRepositoryIntegrationTestBase {
 
@@ -202,8 +203,49 @@ public void shouldApplyPageableCorrectlyWhenUsingFindAll() {
 		repo.save(Arrays.asList(eddard, robb, jon));
 
 		Page<Person> firstPage = repo.findAll(new PageRequest(0, 2));
-		assertThat(firstPage.getContent(), hasSize(2));
-		assertThat(repo.findAll(firstPage.nextPageable()).getContent(), hasSize(1));
+ 		assertThat(firstPage.getContent(), hasSize(2));
+ 		assertThat(repo.findAll(firstPage.nextPageable()).getContent(), hasSize(1));
+	}
+
+	/**
+	 * @see DATAREDIS-547
+	 */
+	@Test
+	public void shouldReturnEmptyListWhenPageableOutOfBoundsUsingFindAll() {
+
+		Person eddard = new Person("eddard", "stark");
+		Person robb = new Person("robb", "stark");
+		Person jon = new Person("jon", "snow");
+
+		repo.save(Arrays.asList(eddard, robb, jon));
+
+		Page<Person> firstPage = repo.findAll(new PageRequest(100, 2));
+		assertThat(firstPage.getContent(), hasSize(0));
+	}
+
+	/**
+	 * @see DATAREDIS-547
+	 */
+	@Test
+	public void shouldReturnEmptyListWhenPageableOutOfBoundsUsingQueryMethod() {
+
+		Person eddard = new Person("eddard", "stark");
+		Person robb = new Person("robb", "stark");
+		Person sansa = new Person("sansa", "stark");
+
+		repo.save(Arrays.asList(eddard, robb, sansa));
+
+		Page<Person> page1 = repo.findPersonByLastname("stark", new PageRequest(1, 3));
+
+		assertThat(page1.getNumberOfElements(), is(0));
+		assertThat(page1.getContent(), hasSize(0));
+		assertThat(page1.getTotalElements(), is(3L));
+
+		Page<Person> page2 = repo.findPersonByLastname("stark", new PageRequest(2, 3));
+
+		assertThat(page2.getNumberOfElements(), is(0));
+		assertThat(page2.getContent(), hasSize(0));
+		assertThat(page2.getTotalElements(), is(3L));
 	}
 
 	/**