Adds an example demonstrating the use of Spring Data Envers.

Closes #603
Original pull request: #604.

jpa/envers/README.adoc

@@ -0,0 +1,8 @@
+# Spring Data JPA - Spring Data Envers
+
+This project contains an example of how to use Spring Data JPA in combination with Spring Data Envers.
+
+Envers module is a Hibernate module that works both with Hibernate and JPA. It aims to provide an easy auditing / versioning solution for entity classes.
+
+Spring Data Envers integrates it with Spring Data JPA and makes revision information available directly from JPA based repositories.
+

jpa/envers/pom.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+		 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<parent>
+		<artifactId>spring-data-jpa-examples</artifactId>
+		<groupId>org.springframework.data.examples</groupId>
+		<version>2.0.0.BUILD-gh-603-SNAPSHOT</version>
+	</parent>
+	<modelVersion>4.0.0</modelVersion>
+
+	<artifactId>spring-data-jpa-envers</artifactId>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.data</groupId>
+			<artifactId>spring-data-envers</artifactId>
+		</dependency>
+	</dependencies>
+</project>

jpa/envers/src/main/java/example/springdata/jpa/envers/EnversDemoConfiguration.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2021 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example.springdata.jpa.envers;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.data.envers.repository.support.EnversRevisionRepositoryFactoryBean;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+
+/**
+ * Configuration for the Envers Demo.
+ * <p>
+ * Note that a special {@literal repositoryFactoryBeanClass} is configured for Spring
+ * Data Envers support.
+ *
+ * @author Jens Schauder
+ */
+@SpringBootApplication
+@EnableJpaRepositories(repositoryFactoryBeanClass = EnversRevisionRepositoryFactoryBean.class)
+public class EnversDemoConfiguration {}

jpa/envers/src/main/java/example/springdata/jpa/envers/Person.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2021 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example.springdata.jpa.envers;
+
+import org.hibernate.envers.Audited;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.Version;
+
+/**
+ * An entity with a single non-technical attribute
+ *
+ * @author Jens Schauder
+ */
+@Entity
+@Audited
+public class Person {
+
+	@Id @GeneratedValue Long id;
+
+	String name;
+
+	@Version Long version;
+
+	public Long getId() {
+		return id;
+	}
+
+	public void setId(Long id) {
+		this.id = id;
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	public Long getVersion() {
+		return version;
+	}
+
+	public void setVersion(Long version) {
+		this.version = version;
+	}
+}

jpa/envers/src/main/java/example/springdata/jpa/envers/PersonRepository.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2021 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example.springdata.jpa.envers;
+
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.history.RevisionRepository;
+
+/**
+ * Repository for persons with revision support
+ *
+ * @author Jens Schauder
+ */
+public interface PersonRepository extends CrudRepository<Person, Long>, RevisionRepository<Person, Long, Long> {
+}

jpa/envers/src/test/java/example/springdata/jpa/envers/EnversIntegrationTests.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2021 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example.springdata.jpa.envers;
+
+import static org.assertj.core.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.data.history.Revision;
+import org.springframework.data.history.RevisionMetadata.RevisionType;
+import org.springframework.data.history.Revisions;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.transaction.support.TransactionTemplate;
+
+import java.util.Iterator;
+
+/**
+ * Demonstrating the usage of Spring Data Envers
+ * 
+ * @author Jens Schauder
+ */
+@ExtendWith(SpringExtension.class)
+@SpringBootTest
+public class EnversIntegrationTests {
+
+	@Autowired PersonRepository repository;
+	@Autowired TransactionTemplate tx;
+
+	@Test
+	void testRepository() {
+
+		Person updated = preparePersonHistory();
+
+		Revisions<Long, Person> revisions = repository.findRevisions(updated.id);
+
+
+		Iterator<Revision<Long, Person>> revisionIterator = revisions.iterator();
+
+		checkNextRevision(revisionIterator, "John", RevisionType.INSERT);
+		checkNextRevision(revisionIterator, "Jonny", RevisionType.UPDATE);
+		checkNextRevision(revisionIterator, null, RevisionType.DELETE);
+		assertThat(revisionIterator.hasNext()).isFalse();
+
+	}
+
+	private void checkNextRevision(Iterator<Revision<Long, Person>> revisionIterator, String name, RevisionType revisionType) {
+
+		assertThat(revisionIterator.hasNext()).isTrue();
+		Revision<Long, Person> revision = revisionIterator.next();
+		assertThat(revision.getEntity().name).isEqualTo(name);
+		assertThat(revision.getMetadata().getRevisionType()).isEqualTo(revisionType);
+	}
+
+	private Person preparePersonHistory() {
+
+		Person john = new Person();
+		john.setName("John");
+
+		//create
+		Person saved = tx.execute(__ -> repository.save(john));
+		assertThat(saved).isNotNull();
+
+		saved.setName("Jonny");
+
+		// update
+		Person updated = tx.execute(__ -> repository.save(saved));
+		assertThat(updated).isNotNull();
+
+		// delete
+		tx.executeWithoutResult(__->repository.delete(updated));
+		return updated;
+	}
+}

jpa/pom.xml

@@ -27,6 +27,7 @@
 		<module>query-by-example</module>
 		<module>vavr</module>
 		<module>deferred</module>
+		<module>envers</module>
 	</modules>
 
 	<profiles>