Pagination now supports sorting by property.

Closes #379
Original Pull Request #381

Author: NiklasLoechte

src/main/java/org/springframework/data/envers/repository/support/EnversRevisionRepositoryImpl.java

@@ -36,6 +36,7 @@
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageImpl;
 import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
 import org.springframework.data.history.AnnotationRevisionMetadata;
 import org.springframework.data.history.Revision;
 import org.springframework.data.history.RevisionMetadata;
@@ -58,6 +59,7 @@
  * @author Julien Millau
  * @author Mark Paluch
  * @author Sander Bylemans
+ * @author Niklas Loechte
  */
 @Transactional(readOnly = true)
 public class EnversRevisionRepositoryImpl<T, ID, N extends Number & Comparable<N>>
@@ -141,18 +143,31 @@ public Revisions<N, T> findRevisions(ID id) {
 		return Revisions.of(revisionList);
 	}
 
+
+	private AuditOrder mapRevisionSort(RevisionSort revisionSort) {
+        return RevisionSort.getRevisionDirection(revisionSort).isDescending() //
+		? AuditEntity.revisionNumber().desc() //
+		: AuditEntity.revisionNumber().asc();
+	}
+
+	private AuditOrder mapPropertySort(Sort sort) {
+		return sort.stream().findFirst().map(order -> order.getDirection().isAscending() ?
+		AuditEntity.property(order.getProperty()).asc() :
+		AuditEntity.property(order.getProperty()).desc())
+		.orElse(AuditEntity.revisionNumber().asc());
+	}
+
 	@SuppressWarnings("unchecked")
 	public Page<Revision<N, T>> findRevisions(ID id, Pageable pageable) {
-
-		AuditOrder sorting = RevisionSort.getRevisionDirection(pageable.getSort()).isDescending() //
-				? AuditEntity.revisionNumber().desc() //
-				: AuditEntity.revisionNumber().asc();
+		AuditOrder orderMapped = (pageable.getSort() instanceof RevisionSort) ? 
+		mapRevisionSort((RevisionSort) pageable.getSort()) :
+        mapPropertySort(pageable.getSort());
 
 		List<Object[]> resultList = createBaseQuery(id) //
-				.addOrder(sorting) //
-				.setFirstResult((int) pageable.getOffset()) //
-				.setMaxResults(pageable.getPageSize()) //
-				.getResultList();
+		.addOrder(orderMapped) //
+		.setFirstResult((int) pageable.getOffset()) //
+		.setMaxResults(pageable.getPageSize()) //
+		.getResultList();
 
 		Long count = (Long) createBaseQuery(id) //
 				.addProjection(AuditEntity.revisionNumber().count()).getSingleResult();

src/test/java/org/springframework/data/envers/repository/support/RepositoryIntegrationTests.java

@@ -18,6 +18,7 @@
 import static org.assertj.core.api.Assertions.*;
 import static org.springframework.data.history.RevisionMetadata.RevisionType.*;
 
+import java.time.Instant;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -31,6 +32,9 @@
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.domain.Sort.Direction;
 import org.springframework.data.envers.Config;
 import org.springframework.data.envers.sample.Country;
 import org.springframework.data.envers.sample.CountryRepository;
@@ -245,6 +249,23 @@ void paginationWithEmptyResult() {
 		check(23L, 0, 0, 0);
 	}
 
+
+	@Test
+	void testSort_pageableByProperty() {
+		Country de = new Country();
+		de.code = "de";
+		de.name = "Deutschland";
+		de.timestamp = Instant.parse("2000-01-01T00:00:00Z");
+		countryRepository.save(de);
+		de.timestamp = Instant.parse("2000-01-04T00:01:00Z");
+		countryRepository.save(de);
+		de.timestamp = Instant.parse("2000-01-04T00:00:00Z");
+		countryRepository.save(de);
+
+		assertThat(countryRepository.findRevisions(de.id, PageRequest.of(0, 3, Sort.by("timestamp"))).map(Revision::getEntity).map(country -> country.timestamp).getContent())
+		.isSortedAccordingTo(Instant::compareTo);
+	}
+
 	void check(Long id, int page, int expectedSize, int expectedTotalSize) {
 
 		Page<Revision<Integer, Country>> revisions = countryRepository.findRevisions(id, PageRequest.of(page, 1));

src/test/java/org/springframework/data/envers/sample/Country.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.envers.sample;
 
+import java.time.Instant;
+
 import javax.persistence.Entity;
 
 import lombok.ToString;
@@ -32,5 +34,8 @@
 public class Country extends AbstractEntity {
 
 	public String code;
+	
+	public Instant timestamp;
+
 	public String name;
 }