Spring Boot TestEntityManager 教程展示了如何使用 TestEntityManager 在 JPA 测试中。TestEntityManager 提供了 EntityManager 方法的子集 对于测试以及常见测试任务的帮助程序方法很有用 例如“保留”或“查找”。

Spring是一个流行的 Java 应用程序框架，用于创建企业应用程序。Spring Boot 是 Spring框架的演变，有助于创建 基于Spring的独立生产级应用程序，只需最少的努力。

测试实体管理器

TestEntityManager允许在测试中使用。春天是一个抽象的结束; 它使开发人员免受JPA的较低级别细节的影响，并带来了许多便利 方法。但是春天允许在需要时使用 应用程序代码和测试。EntityManagerRepositoryEntityManagerEntityManager

在我们的测试中，我们可以注入数据源、@JdbcTemplate、@EntityManager或任何 来自我们应用程序的 Spring 数据存储库。

弹簧测试实体管理器示例

以下应用程序用于保存一些 测试方法中的城市实体。TestEntityManager

pom.xml
src
├───main
│   ├───java
│   │   └───com
│   │       └───zetcode
│   │           │   Application.java
│   │           │   MyRunner.java
│   │           ├───model
│   │           │       City.java
│   │           └───repository
│   │                   CityRepository.java
│   └───resources
└───test└───java└───com└───zetcode└───repositoryCityRepositoryTest.java

这是项目结构。

4.0.0com.zetcodespringboottestentitymanager1.0-SNAPSHOTjarUTF-81717org.springframework.bootspring-boot-starter-parent2.6.7org.springframework.bootspring-boot-starter-data-jpaorg.springframework.bootspring-boot-starter-testtestcom.h2databaseh2runtimeorg.springframework.bootspring-boot-maven-plugin2.6.7

该Maven POM文件包含Spring Data JPA，测试和H2数据库的依赖项。

package com.zetcode.model;import java.util.Objects;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;@Entity
@Table(name = "cities")
public class City {@Id@GeneratedValue(strategy = GenerationType.AUTO)private Long id;private String name;private int population;public City() {}public City(String name, int population) {this.name = name;this.population = population;}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 int getPopulation() {return population;}public void setPopulation(int population) {this.population = population;}@Overridepublic int hashCode() {int hash = 7;hash = 79 * hash + Objects.hashCode(this.id);hash = 79 * hash + Objects.hashCode(this.name);hash = 79 * hash + this.population;return hash;}@Overridepublic boolean equals(Object obj) {if (this == obj) {return true;}if (obj == null) {return false;}if (getClass() != obj.getClass()) {return false;}final City other = (City) obj;if (this.population != other.population) {return false;}if (!Objects.equals(this.name, other.name)) {return false;}return Objects.equals(this.id, other.id);}@Overridepublic String toString() {var builder = new StringBuilder();builder.append("City{id=").append(id).append(", name=").append(name).append(", population=").append(population).append("}");return builder.toString();}
}

这是实体。City

package com.zetcode.repository;import com.zetcode.model.City;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;import java.util.List;@Repository
public interface CityRepository extends CrudRepository {List findByName(String name);
}

CityRepository包含自定义方法。Spring 检查方法的名称，并从其关键字派生查询。findByName()

package com.zetcode;import com.zetcode.model.City;
import com.zetcode.repository.CityRepository;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.stereotype.Component;@Component
public class MyRunner implements CommandLineRunner {private static final Logger logger = LoggerFactory.getLogger(MyRunner.class);@Autowiredprivate CityRepository cityRepository;@Overridepublic void run(String... args) throws Exception {logger.info("Saving cities");cityRepository.save(new City("Bratislava", 432000));cityRepository.save(new City("Budapest", 1759000));cityRepository.save(new City("Prague", 1280000));cityRepository.save(new City("Warsaw", 1748000));logger.info("Retrieving cities");var cities = cityRepository.findAll();cities.forEach(city -> logger.info("{}", city));}
}

Inwe 使用 thes 来保存和 检索实体。数据存储在内存中的 H2 数据库中。MyRunnerCityRepository

package com.zetcode;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplication
public class Application {public static void main(String[] args) {SpringApplication.run(Application.class, args);}
}

设置弹簧引导应用程序。 启用自动配置和 组件扫描。Application@SpringBootApplication

package com.zetcode.repository;import com.zetcode.model.City;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
import org.springframework.boot.test.autoconfigure.orm.jpa.TestEntityManager;
import org.springframework.test.context.junit4.SpringRunner;import static org.assertj.core.api.Assertions.assertThat;
import static org.junit.Assert.assertEquals;@RunWith(SpringRunner.class)
@DataJpaTest
public class CityRepositoryTest {@Autowiredprivate TestEntityManager entityManager;@Autowiredprivate CityRepository repository;@Testpublic void testFindByName() {entityManager.persist(new City("Bratislava", 432000));entityManager.persist(new City("Budapest", 1759000));entityManager.persist(new City("Prague", 1280000));entityManager.persist(new City("Warsaw", 1748000));var cities = repository.findByName("Bratislava");assertEquals(1, cities.size());assertThat(cities).extracting(City::getName).containsOnly("Bratislava");}
}

在中，我们测试自定义 JPA 方法。CityRepositoryTest

@Autowired
private TestEntityManager entityManager;

我们注入。TestEntityManager

@RunWith(SpringRunner.class)
@DataJpaTest
public class CityRepositoryTest {

@DataJpaTest用于测试 JPA 存储库。它与 @RunWith（SpringRunner.class）。注释禁用完全自动配置 并且仅应用与 JPA 测试相关的配置。默认情况下，测试 使用@DataJpaTest注释使用嵌入式内存数据库。

entityManager.persist(new City("Bratislava", 432000));
entityManager.persist(new City("Budapest", 1759000));
entityManager.persist(new City("Prague", 1280000));
entityManager.persist(new City("Warsaw", 1748000));

我们用方法拯救了四个城市。EntityManager'spersist()

var cities = repository.findByName("Bratislava");
assertEquals(1, cities.size());

我们测试该方法返回一个城市。findByName()

assertThat(cities).extracting(City::getName).containsOnly("Bratislava");

在这里，我们测试城市的名称。

$ mvn spring-boot:test

我们运行测试。

在本教程中，我们在测试中使用了。TestEntityManager