DATAMONGO-1085 - Fixed sorting with Querydsl in QueryDslMongoRepository.

We now translate QSort's OrderSpecifiers into appropriate sort criteria.
Previously the OrderSpecifiers were not correctly translated to appropriate property path expressions.

We're now overriding support for findAll(Pageable) and findAll(Sort) to QueryDslMongoRepository to apply special QSort handling.

Original pull request: #236.

Author: Thomas Darimont

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/support/QueryDslMongoRepository.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2012 the original author or authors.
+ * Copyright 2011-2014 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.
@@ -27,6 +27,7 @@
 import org.springframework.data.mongodb.core.MongoTemplate;
 import org.springframework.data.mongodb.repository.query.MongoEntityInformation;
 import org.springframework.data.querydsl.EntityPathResolver;
+import org.springframework.data.querydsl.QSort;
 import org.springframework.data.querydsl.QueryDslPredicateExecutor;
 import org.springframework.data.querydsl.SimpleEntityPathResolver;
 import org.springframework.data.repository.core.EntityInformation;
@@ -44,6 +45,7 @@
  * Special QueryDsl based repository implementation that allows execution {@link Predicate}s in various forms.
  * 
  * @author Oliver Gierke
+ * @author Thomas Darimont
  */
 public class QueryDslMongoRepository<T, ID extends Serializable> extends SimpleMongoRepository<T, ID> implements
 		QueryDslPredicateExecutor<T> {
@@ -105,7 +107,6 @@ public List<T> findAll(Predicate predicate) {
 	 * @see org.springframework.data.querydsl.QueryDslPredicateExecutor#findAll(com.mysema.query.types.Predicate, com.mysema.query.types.OrderSpecifier<?>[])
 	 */
 	public List<T> findAll(Predicate predicate, OrderSpecifier<?>... orders) {
-
 		return createQueryFor(predicate).orderBy(orders).list();
 	}
 
@@ -121,6 +122,28 @@ public Page<T> findAll(Predicate predicate, Pageable pageable) {
 		return new PageImpl<T>(applyPagination(query, pageable).list(), pageable, countQuery.count());
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.repository.support.SimpleMongoRepository#findAll(org.springframework.data.domain.Pageable)
+	 */
+	@Override
+	public Page<T> findAll(Pageable pageable) {
+
+		MongodbQuery<T> countQuery = createQuery();
+		MongodbQuery<T> query = createQuery();
+
+		return new PageImpl<T>(applyPagination(query, pageable).list(), pageable, countQuery.count());
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.repository.support.SimpleMongoRepository#findAll(org.springframework.data.domain.Sort)
+	 */
+	@Override
+	public List<T> findAll(Sort sort) {
+		return applySorting(createQuery(), sort).list();
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.querydsl.QueryDslPredicateExecutor#count(com.mysema.query.types.Predicate)
@@ -136,11 +159,16 @@ public long count(Predicate predicate) {
 	 * @return
 	 */
 	private MongodbQuery<T> createQueryFor(Predicate predicate) {
+		return createQuery().where(predicate);
+	}
 
-		Class<T> domainType = entityInformation.getJavaType();
-
-		MongodbQuery<T> query = new SpringDataMongodbQuery<T>(mongoOperations, domainType);
-		return query.where(predicate);
+	/**
+	 * Creates a {@link MongodbQuery}.
+	 * 
+	 * @return
+	 */
+	private MongodbQuery<T> createQuery() {
+		return new SpringDataMongodbQuery<T>(mongoOperations, entityInformation.getJavaType());
 	}
 
 	/**
@@ -173,6 +201,15 @@ private MongodbQuery<T> applySorting(MongodbQuery<T> query, Sort sort) {
 			return query;
 		}
 
+		// TODO: find better solution than instanceof check
+		if (sort instanceof QSort) {
+
+			List<OrderSpecifier<?>> orderSpecifiers = ((QSort) sort).getOrderSpecifiers();
+			query.orderBy(orderSpecifiers.toArray(new OrderSpecifier<?>[orderSpecifiers.size()]));
+
+			return query;
+		}
+
 		for (Order order : sort) {
 			query.orderBy(toOrder(order));
 		}

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/AbstractPersonRepositoryIntegrationTests.java

@@ -24,6 +24,7 @@
 import java.util.HashSet;
 import java.util.List;
 
+import org.hamcrest.Matchers;
 import org.junit.Before;
 import org.junit.Ignore;
 import org.junit.Test;
@@ -47,6 +48,7 @@
 import org.springframework.data.mongodb.core.MongoOperations;
 import org.springframework.data.mongodb.core.query.BasicQuery;
 import org.springframework.data.mongodb.repository.Person.Sex;
+import org.springframework.data.querydsl.QSort;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
 /**
@@ -1060,4 +1062,79 @@ public void shouldBindPlaceholdersUsedAsKeysCorrectly() {
 		assertThat(persons, hasSize(1));
 		assertThat(persons, hasItem(alicia));
 	}
+
+	/**
+	 * @see DATAMONGO-1085
+	 */
+	@Test
+	public void shouldSupportSortingByQueryDslOrderSpecifier() {
+
+		repository.deleteAll();
+
+		List<Person> persons = new ArrayList<Person>();
+
+		for (int i = 0; i < 3; i++) {
+			Person person = new Person(String.format("Siggi %s", i), "Bar", 30);
+			person.setAddress(new Address(String.format("Street %s", i), "12345", "SinCity"));
+			persons.add(person);
+		}
+
+		repository.save(persons);
+
+		QPerson person = QPerson.person;
+
+		Iterable<Person> result = repository.findAll(person.firstname.isNotNull(), person.address.street.desc());
+
+		assertThat(result, is(Matchers.<Person> iterableWithSize(persons.size())));
+		assertThat(result.iterator().next().getFirstname(), is(persons.get(2).getFirstname()));
+	}
+
+	/**
+	 * @see DATAMONGO-1085
+	 */
+	@Test
+	public void shouldSupportSortingWithQSortByQueryDslOrderSpecifier() throws Exception {
+
+		repository.deleteAll();
+
+		List<Person> persons = new ArrayList<Person>();
+
+		for (int i = 0; i < 3; i++) {
+			Person person = new Person(String.format("Siggi %s", i), "Bar", 30);
+			person.setAddress(new Address(String.format("Street %s", i), "12345", "SinCity"));
+			persons.add(person);
+		}
+
+		repository.save(persons);
+
+		PageRequest pageRequest = new PageRequest(0, 2, new QSort(person.address.street.desc()));
+		Iterable<Person> result = repository.findAll(pageRequest);
+
+		assertThat(result, is(Matchers.<Person> iterableWithSize(2)));
+		assertThat(result.iterator().next().getFirstname(), is("Siggi 2"));
+	}
+
+	/**
+	 * @see DATAMONGO-1085
+	 */
+	@Test
+	public void shouldSupportSortingWithQSort() throws Exception {
+
+		repository.deleteAll();
+
+		List<Person> persons = new ArrayList<Person>();
+
+		for (int i = 0; i < 3; i++) {
+			Person person = new Person(String.format("Siggi %s", i), "Bar", 30);
+			person.setAddress(new Address(String.format("Street %s", i), "12345", "SinCity"));
+			persons.add(person);
+		}
+
+		repository.save(persons);
+
+		Iterable<Person> result = repository.findAll(new QSort(person.address.street.desc()));
+
+		assertThat(result, is(Matchers.<Person> iterableWithSize(persons.size())));
+		assertThat(result.iterator().next().getFirstname(), is("Siggi 2"));
+	}
 }