EntityManager 没有正确持久化答案

【问题标题】：EntityManager not persisting properlyEntityManager 没有正确持久化
【发布时间】：2019-04-04 14:44:44
【问题描述】：

我有一个带有 hibernate 和 jpa 的 spring-boot 应用程序。当尝试创建Foo 实体的新实例（直接通过JpaRepository 或entityManager）时，一切似乎都很好（没有错误，并且返回的实例的ids 正在递增），但是这些实例既没有保存到数据库中，也没有保存到数据库中。向 orm 查询时返回（JpaRepository.findAll() 和 entityManager.find(FooImpl.class, id) 均不存在）

我尝试调用 saveAndFlush 方法而不是 save 的 JpaRepository -> 抛出错误（无事务）

我尝试手动刷新entityManager -> 同样的错误。

我检查了entityManager 的 flushMode -> 它是“自动”

我尝试使用entityManager.find(CourseImpl.class, id) 直接查询实例 -> 没有找到实例

我尝试用 @Transactional 注释服务方法 -> 没有区别

我的实体：

@Entity
@Table(name = "foo")
public class FooImpl implements Foo{
    @Id
    @GeneratedValue
    private Long id;

    @Column
    private String someOtherValue;

    ...

    @Override
    public Long getId() {
        return id;
    }

    @Override
    public void setId(Long id) {
        this.id = id;
    }
}

我的Application.java：

@SpringBootApplication
@EnableJpaRepositories
@EnableTransactionManagement
@EnableJpaAuditing
public class Application extends SpringBootServletInitializer implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(Application.class);
    }

    @Bean
    @Primary
    @ConfigurationProperties(prefix = "spring.datasource")
    public javax.sql.DataSource primaryDataSource() {

        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
        dataSource.setUsername("username");
        dataSource.setPassword("n0tRea1Pasw0rd");
        dataSource.setUrl("jdbc\\:mysql\\://localhost\\:3306/bar");
        dataSource.setSchema("bar");

        return dataSource;
    }

    @Bean(name = "entityManagerFactory")
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryBean() {

        LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();
        entityManagerFactoryBean.setJpaVendorAdapter(new HibernateJpaVendorCustomAdapter());
        entityManagerFactoryBean.setDataSource(primaryDataSource());
        entityManagerFactoryBean.setPersistenceProviderClass(HibernatePersistenceProvider.class);
        entityManagerFactoryBean.setPackagesToScan(new String[] { "org.baeldung.persistence.model", "cz.mycompany.bar.domain"});

        Properties properties = new Properties();
        properties.setProperty("hibernate.dialect", "org.hibernate.dialect.MySQL5InnoDBDialect");
        properties.setProperty("hibernate.hbm2ddl.auto", "update");

        entityManagerFactoryBean.setJpaProperties(properties);

        return entityManagerFactoryBean;
    }

    public static void main(String[] args) {
        applicationContext = SpringApplication.run(Application.class, args);
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) {
        Application.applicationContext = applicationContext;
    }
}

来自服务的相关方法：

...
    @Override
    public Foo create(){
        return fooRepository.save(new FooImpl());
    }

    @Override
    public List<Foo> findAll() {
        return Lists.newArrayList(fooRepository.findAll());
    }
...

我的fooRepository:

@RepositoryRestResource(collectionResourceRel = "foo", path = "foo")
public interface FooRepository extends JpaRepository<FooImpl, Long> {}

为此我还尝试了自定义实现：

public class FooRepositoryImpl implements FooRepository {
    @PersistenceContext
    private EntityManager entityManager;
...
    @Override
    public <S extends FooImpl> S save(S entity) {
        entityManager.persist(entity);
//        entityManager.flush(); this threw error
        return entity;
    }
...
}

当前状态是升级到 Java 11 的结果，所以我包含了 pom.xml 的相关部分：

<project>
...
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.3.RELEASE</version>
        <relativePath/>
    </parent>

    <properties>
        ...
        <java.version>11.0.2</java.version>
        <maven.compiler.source>11.0.2</maven.compiler.source>
        <maven.compiler.target>11.0.2</maven.compiler.target>

        <jsoup.version>1.7.3</jsoup.version>
        ...
    </properties>

    <dependencies>
        ...
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <!-- exclusion of tomcat because of jetty -->
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-rest</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
            <version>2.1.3.RELEASE</version>
            <exclusions>
                <exclusion>
                    <groupId>org.apache.tomcat</groupId>
                    <artifactId>tomcat-jdbc</artifactId>
                </exclusion>

                <exclusion>
                    <groupId>org.hibernate</groupId>
                    <artifactId>hibernate-core</artifactId>
                </exclusion>

                <exclusion>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-orm</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>5.1.5.RELEASE</version>
            <!--<version>${spring.version}</version>-->
            <exclusions>
                <exclusion>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-web</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.3.7.Final</version>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>5.4.1.Final</version>
            <exclusions>
                <exclusion>
                    <groupId>org.hibernate</groupId>
                    <artifactId>hibernate-core</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>6.0.6</version>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.15</version>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
        </dependency>

        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.8.1</version>
        </dependency>

        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.1</version>
        </dependency>

        <dependency>
            <groupId>javax.persistence</groupId>
            <artifactId>javax.persistence-api</artifactId>
            <version>2.2</version>
        </dependency>



    </dependencies>

    <build>
        ...
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <dependencies>
                    <dependency>
                        <groupId>org.springframework</groupId>
                        <artifactId>springloaded</artifactId>
                        <version>1.2.8.RELEASE</version>
                    </dependency>
                </dependencies>
                <configuration>
                    <jvmArguments>
                        -Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=5005
                    </jvmArguments>
                </configuration>
            </plugin>
            ...
        </plugins>
    </build>

    <profiles>

        <!-- tomcat - default -->
        <profile>
            <id>tomcat</id>
            <activation>
                <activeByDefault>true</activeByDefault>
            </activation>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                </dependency>

                <dependency>
                    <groupId>org.apache.tomcat.embed</groupId>
                    <artifactId>tomcat-embed-jasper</artifactId>
                </dependency>

                <dependency>
                    <groupId>org.apache.tomcat</groupId>
                    <artifactId>tomcat-jdbc</artifactId>
                </dependency>
            </dependencies>
        </profile>
        ...
    </profiles>
</project>

【问题讨论】：

您可以尝试在具有@ EnableTransactionManagement 注释的类中添加@Configuration 注释吗？
@Gimby 试过了，我没有注意到行为差异
这是我的思路：如果你在 Spring Boot 中暴露 bean，它需要在一个带有 @Configuration 注释的类中。您向我描述的情况听起来好像插入没有发生在您在此处指定的数据库中，而是发生在完全没有数据源配置时 Spring 将设置的内存数据库中。如...当此类中的 bean 实际上不可用时。

标签： java hibernate spring-boot jpa

【解决方案1】：

问题是奇怪的默认事务处理（JPA 存储库将它们的方法包装在 @Transactional 中，所以我是否也这样做并不重要）。通过创建“自定义”事务管理器 bean 解决了问题。特别是 Application.java 被这个丰富了：

...
    @Bean
    public PlatformTransactionManager transactionManager() {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(entityManagerFactoryBean().getObject());
        return transactionManager;
    }
...

【讨论】：