spring-projects#134 - Added example for using Optional as query method parameter.

odrotbohm · odrotbohm · commit d9dfb81e126b · 2015-10-07T19:50:49.000+02:00
Got rid of Guava dependency in favor of JDK 8's Optional. Upgraded basic JPA example to Spring Data Hopper to get access to the newly introduced functionality.
diff --git a/jpa/example/pom.xml b/jpa/example/pom.xml
@@ -13,16 +13,9 @@
 
 	<name>Spring Data JPA - Example</name>
 	<description>Small sample project showing the usage of Spring Data JPA.</description>
-
-	<dependencies>
-
-		<dependency>
-			<groupId>com.google.guava</groupId>
-			<artifactId>guava</artifactId>
-			<version>16.0.1</version>
-		</dependency>
-
-	</dependencies>
+	<properties>
+		<spring-data-releasetrain.version>Hopper-BUILD-SNAPSHOT</spring-data-releasetrain.version>
+	</properties>
 
 	<build>
 		<plugins>
diff --git a/jpa/example/src/main/java/example/springdata/jpa/simple/SimpleUserRepository.java b/jpa/example/src/main/java/example/springdata/jpa/simple/SimpleUserRepository.java
@@ -16,15 +16,14 @@
 package example.springdata.jpa.simple;
 
 import java.util.List;
+import java.util.Optional;
 
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Slice;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.CrudRepository;
 
-import com.google.common.base.Optional;
-
 /**
  * Simple repository interface for {@link User} instances. The interface is used to declare so called query methods,
  * methods to retrieve single entities or collections of them.
@@ -44,7 +43,13 @@ public interface SimpleUserRepository extends CrudRepository<User, Long> {
 	 */
 	User findByTheUsersName(String username);
 
-	Optional<User> findByUsername(String username);
+	/**
+	 * Uses {@link Optional} as return and parameter type.
+	 * 
+	 * @param username
+	 * @return
+	 */
+	Optional<User> findByUsername(Optional<String> username);
 
 	/**
 	 * Find all users with the given lastname. This method will be translated into a query by constructing it directly
@@ -67,7 +72,7 @@ public interface SimpleUserRepository extends CrudRepository<User, Long> {
 
 	/**
 	 * Returns all users with the given name as first- or lastname. This makes the query to method relation much more
-	 * refactoring safe as the order of the method parameters is completely irrelevant.
+	 * refactoring-safe as the order of the method parameters is completely irrelevant.
 	 * 
 	 * @param name
 	 * @return
diff --git a/jpa/example/src/test/java/example/springdata/jpa/simple/SimpleUserRepositoryTests.java b/jpa/example/src/test/java/example/springdata/jpa/simple/SimpleUserRepositoryTests.java
@@ -22,6 +22,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Optional;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -88,13 +89,13 @@ public void findByFirstnameOrLastname() throws Exception {
 	}
 
 	@Test
-	public void useGuavaOptionalInsteadOfNulls() {
+	public void useOptionalAsReturnAndParameterType() {
 
-		assertThat(repository.findByUsername("foobar").isPresent(), is(false));
+		assertThat(repository.findByUsername(Optional.of("foobar")), is(Optional.empty()));
 
 		repository.save(user);
 
-		assertThat(repository.findByUsername("foobar").isPresent(), is(true));
+		assertThat(repository.findByUsername(Optional.of("foobar")).isPresent(), is(true));
 	}
 
 	@Test
