From 83571229503cbe80ae2a5da76a7db461d4a32167 Mon Sep 17 00:00:00 2001
From: James Thomson <info@longwater.co.uk>
Date: Thu, 10 Mar 2016 21:31:23 +0000
Subject: [PATCH] DATACOUCH-211 - Applying sort that's passed in via the
 Pagenate object in call to N1qlCouchbaseRepository::findAll

---
 .../N1qlCouchbaseRepositoryTests.java         | 20 +++++++++++++++++++
 .../support/N1qlCouchbaseRepository.java      | 15 +++++++++++++-
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/src/integration/java/org/springframework/data/couchbase/repository/N1qlCouchbaseRepositoryTests.java b/src/integration/java/org/springframework/data/couchbase/repository/N1qlCouchbaseRepositoryTests.java
index c11fa4e4..30d7c26a 100644
--- a/src/integration/java/org/springframework/data/couchbase/repository/N1qlCouchbaseRepositoryTests.java
+++ b/src/integration/java/org/springframework/data/couchbase/repository/N1qlCouchbaseRepositoryTests.java
@@ -36,6 +36,8 @@ import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.TestExecutionListeners;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
+import java.util.List;
+
 /**
  * This tests PaginAndSortingRepository features in the Couchbase connector.
  *
@@ -105,4 +107,22 @@ public class N1qlCouchbaseRepositoryTests {
     assertEquals(15, page1.getTotalElements()); //12 generated parties + 3 specifically crafted party
     assertEquals(8, page1.getNumberOfElements());
   }
+
+  @Test
+  public void shouldPageThroughSortedEntities() {
+    Pageable pageable = new PageRequest(0, 8, Sort.Direction.DESC, "attendees");
+
+    Page<Party> page1 = repository.findAll(pageable);
+    assertEquals(15, page1.getTotalElements()); //12 generated parties + 3 specifically crafted party
+    assertEquals(8, page1.getNumberOfElements());
+
+    List<Party> parties = page1.getContent();
+    Long previousAttendees = null;
+    for (Party party : parties) {
+      if (previousAttendees != null) {
+        assertTrue(party.getAttendees() <= previousAttendees);
+      }
+      previousAttendees = party.getAttendees();
+    }
+  }
 }
diff --git a/src/main/java/org/springframework/data/couchbase/repository/support/N1qlCouchbaseRepository.java b/src/main/java/org/springframework/data/couchbase/repository/support/N1qlCouchbaseRepository.java
index ee950d16..dab43b9f 100644
--- a/src/main/java/org/springframework/data/couchbase/repository/support/N1qlCouchbaseRepository.java
+++ b/src/main/java/org/springframework/data/couchbase/repository/support/N1qlCouchbaseRepository.java
@@ -25,6 +25,8 @@ import com.couchbase.client.java.query.SimpleN1qlQuery;
 import com.couchbase.client.java.query.Statement;
 import com.couchbase.client.java.query.consistency.ScanConsistency;
 import com.couchbase.client.java.query.dsl.Expression;
+import com.couchbase.client.java.query.dsl.path.GroupByPath;
+import com.couchbase.client.java.query.dsl.path.LimitPath;
 import com.couchbase.client.java.query.dsl.path.WherePath;
 
 import org.springframework.data.couchbase.core.CouchbaseOperations;
@@ -93,11 +95,22 @@ public class N1qlCouchbaseRepository<T, ID extends Serializable>
 
     //prepare elements of the data query
     WherePath selectFrom = N1qlUtils.createSelectFromForEntity(getCouchbaseOperations().getCouchbaseBucket().name());
+
+    //add where criteria
     Expression whereCriteria = N1qlUtils.createWhereFilterForEntity(null, getCouchbaseOperations().getConverter(),
         getEntityInformation());
+    GroupByPath groupBy = selectFrom.where(whereCriteria);
+
+    //apply the sort if available
+    LimitPath limitPath = groupBy;
+    if (pageable.getSort() != null) {
+      com.couchbase.client.java.query.dsl.Sort[] orderings = N1qlUtils.createSort(pageable.getSort(),
+          getCouchbaseOperations().getConverter());
+      limitPath = groupBy.orderBy(orderings);
+    }
 
     //apply the paging
-    Statement pageStatement = selectFrom.where(whereCriteria).limit(pageable.getPageSize()).offset(pageable.getOffset());
+    Statement pageStatement = limitPath.limit(pageable.getPageSize()).offset(pageable.getOffset());
 
     //fire the query
     N1qlQuery query = N1qlQuery.simple(pageStatement, N1qlParams.build().consistency(consistency));