Show how to use Limit with repository queries.

Add methods taking a Limit parameter to various samples.

Original pull request: #672
Closes #671

mongodb/example/src/main/java/example/springdata/mongodb/customer/CustomerRepository.java

@@ -18,6 +18,7 @@ package example.springdata.mongodb.customer;
 import java.util.List;
 import java.util.stream.Stream;
 
+import org.springframework.data.domain.Limit;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.geo.Distance;
 import org.springframework.data.geo.GeoResults;
@@ -41,6 +42,15 @@ public interface CustomerRepository extends CrudRepository<Customer, String> {
 	 */
 	List<Customer> findByLastname(String lastname, Sort sort);
 
+	/**
+	 * Derived query reducing result size to a given {@link Limit}.
+	 *
+	 * @param lastname
+	 * @param maxResults the maximum number of results returned.
+	 * @return
+	 */
+	List<Customer> findByLastname(String lastname, Limit maxResults);
+
 	/**
 	 * Showcase for a repository query using geospatial functionality.
 	 *

mongodb/example/src/test/java/example/springdata/mongodb/customer/CustomerRepositoryIntegrationTest.java

@@ -27,6 +27,7 @@ import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.data.mongo.DataMongoTest;
+import org.springframework.data.domain.Limit;
 import org.springframework.data.geo.Distance;
 import org.springframework.data.geo.Metrics;
 import org.springframework.data.geo.Point;
@@ -96,6 +97,17 @@ class CustomerRepositoryIntegrationTest {
 		assertThat(result.get(1)).isEqualTo(oliver);
 	}
 
+	/**
+	 * Test case to show how to reduce result size with dynamic {@link Limit}.
+	 */
+	@Test
+	void limitResultSize() {
+
+		var result = repository.findByLastname("Matthews", Limit.of(1));
+
+		assertThat(result).hasSize(1);
+	}
+
 	/**
 	 * Test case to show the usage of Java {@link Stream}.
 	 */

mongodb/reactive/src/main/java/example/springdata/mongodb/people/ReactivePersonRepository.java

@@ -15,6 +15,9 @@
  */
 package example.springdata.mongodb.people;
 
+import java.util.List;
+
+import org.springframework.data.domain.Limit;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
@@ -37,6 +40,17 @@ public interface ReactivePersonRepository extends ReactiveCrudRepository<Person,
 	 */
 	Flux<Person> findByLastname(String lastname);
 
+	/**
+	 * Find at most the number of users defined via maxResults with the given lastname.
+	 * This method will be translated into a query by constructing it directly from the method name as there is no other
+	 * query declared.
+	 *
+	 * @param lastname
+	 * @param maxResults the maximum number of results returned.
+	 * @return
+	 */
+	Flux<Person> findByLastname(String lastname, Limit maxResults);
+
 	/**
 	 * String query selecting one entity.
 	 *

mongodb/reactive/src/test/java/example/springdata/mongodb/people/ReactivePersonRepositoryIntegrationTest.java

@@ -18,6 +18,7 @@ package example.springdata.mongodb.people;
 import static org.assertj.core.api.Assertions.*;
 
 import example.springdata.mongodb.util.MongoContainers;
+import org.springframework.data.domain.Limit;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
@@ -157,6 +158,14 @@ class ReactivePersonRepositoryIntegrationTest {
 		repository.findByLastname("White").as(StepVerifier::create).expectNextCount(2).verifyComplete();
 	}
 
+	/**
+	 * Limit result size.
+	 */
+	@Test
+	void shouldLimitResultSize() {
+		repository.findByLastname("White", Limit.of(1)).as(StepVerifier::create).expectNextCount(1).verifyComplete();
+	}
+
 	/**
 	 * Fetch data using a string query.
 	 */