How SpringBoot uses TestEntityManager for JPA integration testing
Introduction
In the development process, JPA is one of the commonly used persistence frameworks, which can help us map objects to the database and provide a series of APIs for operating the database. When developing and testing JPA, we usually use some memory databases (such as H2, HSQLDB, etc.) to avoid modifying the real database, so as to ensure data security and repeatability. However, only using an in-memory database cannot completely simulate data operations in a real environment, and we also need to conduct integration tests to ensure the correctness and robustness of the application.
TestEntityManager is a testing framework provided by Spring Framework, which can help us with JPA integration testing. In this article, we describe how to use TestEntityManager for JPA integration testing.
Environmental preparation
Before starting JPA integration testing, we need to prepare the following environment:
- JDK 8 or above
- Maven
- SpringBoot 2.x or above
create project
First, we need to create a SpringBoot project. Execute the following commands on the command line:
mvn archetype:generate -DgroupId=com.example -DartifactId=jpa-test-demo -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false
Next, add the following dependencies to the project's pom.xml file:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
These dependencies will help us create a SpringBoot-based JPA application and add TestEntityManager dependencies.
Write test cases
Create a test class in your project and write your test cases in that class. For example, we can create a UserRepository class and write a test case to test the methods of this class:
@RunWith(SpringRunner.class)
@DataJpaTest
public class UserRepositoryTest {
@Autowired
private TestEntityManager entityManager;
@Autowired
private UserRepository userRepository;
@Test
public void testFindById() {
User user = new User();
user.setName("John Doe");
user.setAge(30);
entityManager.persist(user);
entityManager.flush();
Optional<User> result = userRepository.findById(user.getId());
assertThat(result.isPresent()).isTrue();
assertThat(result.get().getName()).isEqualTo("John Doe");
assertThat(result.get().getAge()).isEqualTo(30);
}
}
In the above code, we use the TestEntityManager class to operate the memory database, and use the assertThat method to assert whether the returned results meet expectations.
Note that we have used the @RunWith(SpringRunner.class) annotation on the class to tell JUnit to use the test runner provided by Spring Test to run the test case. At the same time, we also used the @DataJpaTest annotation to tell Spring Boot to start a lightweight Spring application and automatically configure JPA-related components.
run test case
After writing the test cases, we can use the following command to run the tests:
mvn test
After the test run is complete, we can see the test results in the console.
Summarize
In this article, we covered how to use TestEntityManager for JPA integration testing. First, we need to prepare the necessary environment, then create a SpringBoot-based project, and add TestEntityManager dependencies. Next, we write test cases in the test class and use the TestEntityManager class to operate the memory database. Finally, we can use Maven commands to run the tests and view the test results. Through the introduction of this article, I believe readers have mastered the basic method of using TestEntityManager for JPA integration testing.