DATAJPA-486 - Added support for sliced query execution.

Added support for Slice as return type for query methods. The execution will expand the requested page size by one to read one more element than actually requested. If that additional element is returned, it will considered to be an indicator for whether a next slice is available.

Related issues: DATACMNS-397.

src/test/java/org/springframework/data/jpa/repository/UserRepositoryFinderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2011 the original author or authors.
+ * Copyright 2008-2014 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@ package org.springframework.data.jpa.repository;
 
 import static org.hamcrest.CoreMatchers.*;
 import static org.junit.Assert.*;
+import static org.springframework.data.domain.Sort.Direction.*;
 
 import java.util.Arrays;
 import java.util.List;
@@ -27,8 +28,8 @@ import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Slice;
 import org.springframework.data.domain.Sort;
-import org.springframework.data.domain.Sort.Direction;
 import org.springframework.data.jpa.domain.sample.User;
 import org.springframework.data.jpa.repository.sample.UserRepository;
 import org.springframework.data.repository.query.QueryLookupStrategy;
@@ -47,8 +48,7 @@ import org.springframework.transaction.annotation.Transactional;
 @Transactional
 public class UserRepositoryFinderTests {
 
-	@Autowired
-	UserRepository userRepository;
+	@Autowired UserRepository userRepository;
 
 	User dave, carter, oliver;
 
@@ -136,6 +136,9 @@ public class UserRepositoryFinderTests {
 		assertThat(result.get(0), is(oliver));
 	}
 
+	/**
+	 * @see DATAJPA-92
+	 */
 	@Test
 	public void findsByLastnameIgnoringCase() throws Exception {
 		List<User> result = userRepository.findByLastnameIgnoringCase("BeAUfoRd");
@@ -143,6 +146,9 @@ public class UserRepositoryFinderTests {
 		assertThat(result.get(0), is(carter));
 	}
 
+	/**
+	 * @see DATAJPA-92
+	 */
 	@Test
 	public void findsByLastnameIgnoringCaseLike() throws Exception {
 		List<User> result = userRepository.findByLastnameIgnoringCaseLike("BeAUfo%");
@@ -150,6 +156,9 @@ public class UserRepositoryFinderTests {
 		assertThat(result.get(0), is(carter));
 	}
 
+	/**
+	 * @see DATAJPA-92
+	 */
 	@Test
 	public void findByLastnameAndFirstnameAllIgnoringCase() throws Exception {
 		List<User> result = userRepository.findByLastnameAndFirstnameAllIgnoringCase("MaTTheWs", "DaVe");
@@ -157,12 +166,15 @@ public class UserRepositoryFinderTests {
 		assertThat(result.get(0), is(dave));
 	}
 
+	/**
+	 * @see DATAJPA-94
+	 */
 	@Test
 	public void respectsPageableOrderOnQueryGenerateFromMethodName() throws Exception {
-		Page<User> ascending = userRepository.findByLastnameIgnoringCase(new PageRequest(0, 10, new Sort(Direction.ASC,
-				"firstname")), "Matthews");
-		Page<User> descending = userRepository.findByLastnameIgnoringCase(new PageRequest(0, 10, new Sort(Direction.DESC,
-				"firstname")), "Matthews");
+		Page<User> ascending = userRepository.findByLastnameIgnoringCase(
+				new PageRequest(0, 10, new Sort(ASC, "firstname")), "Matthews");
+		Page<User> descending = userRepository.findByLastnameIgnoringCase(new PageRequest(0, 10,
+				new Sort(DESC, "firstname")), "Matthews");
 		assertThat(ascending.getTotalElements(), is(2L));
 		assertThat(descending.getTotalElements(), is(2L));
 		assertThat(ascending.getContent().get(0).getFirstname(), is(not(equalTo(descending.getContent().get(0)
@@ -171,4 +183,15 @@ public class UserRepositoryFinderTests {
 		assertThat(ascending.getContent().get(1).getFirstname(), is(equalTo(descending.getContent().get(0).getFirstname())));
 	}
 
+	/**
+	 * @see DATAJPA-486
+	 */
+	@Test
+	public void executesQueryToSlice() {
+
+		Slice<User> slice = userRepository.findSliceByLastname("Matthews", new PageRequest(0, 1, ASC, "firstname"));
+
+		assertThat(slice.getContent(), hasItem(dave));
+		assertThat(slice.hasNext(), is(true));
+	}
 }

src/test/java/org/springframework/data/jpa/repository/sample/UserRepository.java

@@ -23,6 +23,7 @@ import javax.persistence.QueryHint;
 
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Slice;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.jpa.domain.sample.SpecialUser;
 import org.springframework.data.jpa.domain.sample.User;
@@ -305,4 +306,9 @@ public interface UserRepository extends JpaRepository<User, Integer>, JpaSpecifi
 	 * @see DATAJPA-454
 	 */
 	List<User> findByBinaryData(byte[] data);
+
+	/**
+	 * @see DATAJPA-486
+	 */
+	Slice<User> findSliceByLastname(String lastname, Pageable pageable);
 }