问题：

如何在没有Spring Boot的情况下使用JPA存储库

孔砚

2023-03-14

我有一个现有的spring 4项目（mvc、jdbc等），我试图将其移植到spring boot，但我做不到（许多依赖项存在问题，没有人能解释我是如何做到这一点的）。但现在我只想在现有项目中使用Spring数据JPA。这是pom的一个主要依赖项：

<properties>
        <jetty.version>9.3.5.v20151012</jetty.version>
        <spring.version>4.3.12.RELEASE</spring.version>
        <spring.boot.version>1.5.8.RELEASE</spring.boot.version>
        <spring.security.version>4.2.3.RELEASE</spring.security.version>
        <quartz.version>2.2.1</quartz.version>
        <slf4j.version>1.7.5</slf4j.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <hibernate-version>5.3.3.Final</hibernate-version>
    </properties>

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web-services</artifactId>
            <version>${spring.boot.version}</version>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-logging</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-validation</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.jboss.logging</groupId>
                    <artifactId>jboss-logging</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.fasterxml.jackson.core</groupId>
                    <artifactId>jackson-core</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.fasterxml.jackson.core</groupId>
                    <artifactId>jackson-databind</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.fasterxml.jackson.core</groupId>
                    <artifactId>jackson-annotations</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.hibernate</groupId>
                    <artifactId>hibernate-validator</artifactId>
                </exclusion>

            </exclusions>
        </dependency>
    <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.4</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>2.0.5.RELEASE</version>
        </dependency>
<dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>${hibernate-version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>${hibernate-version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.0-api</artifactId>
            <version>1.0.1.Final</version>
        </dependency>

<dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-config</artifactId>
            <version>4.2.1.RELEASE</version>
        </dependency>

我使用EntityManagerFactorybean（在所有示例中都使用）完成了现有配置。数据库配置：

@Configuration
@ComponentScan("ru.testproject.*")
@EnableTransactionManagement
@EnableJpaRepositories("ru.testproject.*")
public class DatabaseConfig {

    @Value("${postgresql.address}")
    String address;
    @Value("${postgresql.database}")
    String database;
    @Value("${postgresql.user}")
    String user;
    @Value("${postgresql.password}")
    String password;
    @Value("${db.type}")
    String dbType;

    @Bean
    public DataSource dataSource() {

        if (DB_TYPE_POSTGRESQL.equalsIgnoreCase(dbType)) {
            return postresqlDataSource();
        } else {
            return derbyDataSource();
        }

    }

    @Bean
    public DataSourceTransactionManager dataSourceTransactionManager(DataSource dataSource) {
        DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
        dataSourceTransactionManager.setDataSource(dataSource);

        return dataSourceTransactionManager;
    }

    private HikariDataSource derbyDataSource() {

        try {
            String appHome = System.getProperty(Property.APP_HOME);

            Path path = Paths.get(appHome, DATABASE_NAME);
            String databaseName = path.toString();

            databaseName = StringUtils.replaceChars(databaseName, '\\', '/');

            Class.forName(DB.DB_DRIVER_DERBY).newInstance();

            EmbeddedDataSource embeddedDataSource = new EmbeddedDataSource();
            String dbName = databaseName;

            embeddedDataSource.setDatabaseName(dbName);
            embeddedDataSource.setCreateDatabase("create");

            embeddedDataSource.setUser("application");
            embeddedDataSource.setPassword("");

            HikariConfig config = new HikariConfig();
            config.setDataSource(embeddedDataSource);
            config.setMaximumPoolSize(10);
            config.setAutoCommit(true);

            HikariDataSource hikariDataSource = new HikariDataSource(config);

            return hikariDataSource;
        } catch (ClassNotFoundException | InstantiationException | IllegalAccessException e) {
            throw new IllegalStateException("error connection Derby");
        }

    }

    private HikariDataSource postresqlDataSource() {

        if (StringUtils.isBlank(address)
                || StringUtils.isBlank(database)
                || StringUtils.isBlank(user)
                || StringUtils.isBlank(password)) {
            throw new IllegalStateException("error params Postgresql");
        }

        HikariConfig config = new HikariConfig();
        String jdbcUrl = MessageFormat.format(POSTGRESQL, address, database);
        config.setJdbcUrl(jdbcUrl);
        config.setUsername(user);
        config.setPassword(password);
        config.setMaximumPoolSize(10);
        config.setAutoCommit(false);

        return new HikariDataSource(config);
    }

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() throws SQLException {

        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setGenerateDdl(true);

        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
        factory.setJpaVendorAdapter(vendorAdapter);
        factory.setPackagesToScan("ru.testproject.hibernate.*");
        factory.setDataSource(dataSource());
        factory.afterPropertiesSet();
        factory.setPersistenceUnitName("test");
        return factory;
    }

}

用于测试的Derby数据库。但主要数据库类型是带有HikariCP的PostgreSQL。我已经在项目中添加了HQL支持，它工作正常。但是当我尝试添加JAP存储库支持时，我有很多问题。我有实体：

@Entity
@Table(name = "users", schema = "public", catalog = "test")
public class Users {
    private int id;
    private String username;
    private String password;
    private String email;

    @Id
    @Column(name = "id", nullable = false)
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    @Basic
    @Column(name = "username", nullable = false, length = 64)
    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    @Basic
    @Column(name = "password", nullable = false, length = 64)
    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Basic
    @Column(name = "email", nullable = false, length = 128)
    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Users that = (Users) o;
        return id == that.id &&
                Objects.equals(username, that.username) &&
                Objects.equals(password, that.password) &&
                Objects.equals(email, that.email);
    }

    @Override
    public int hashCode() {
        return Objects.hash(id, username, password, email);
    }
}

和存储库：

@Repository
public interface UsersRepository extends CrudRepository<Users, Long> {

    @Query("select b from Users b where b.username = :username")
    Users findByName(@Param("username") String username);
}

它只是一个测试存储库。为了使用该存储库，我创建了带有实现的服务：

@Service
public interface UserService {

    void delete(long id);
    Users getByName(String name);
    Optional<Users> getById(Long id);
    Users editUsers(Users user);
}

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UsersRepository usersRepository;

//    @PersistenceContext(unitName = "test")
//    private EntityManager em;

    @Override
    public void delete(long id) {
        usersRepository.deleteById(id);
    }

    @Override
    public Optional<Users> getById(Long id) {
        return usersRepository.findById(id);
    }

    @Override
    public Users getByName(String name) {
        return usersRepository.findByName(name);
    }

    @Override
    public Users editUsers(Users user) {
        return usersRepository.save(user);
    }
}

我使用的存储库是这样的：

@Autowired
    private UserService service;
...
Users entry = service.getById(1L).get();

仅此而已。我不使用Spring Boot（如上所述）并在应用程序失败并出错时启动：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in ru.testproject.config.DBConfig: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean]: Factory method 'entityManagerFactory' threw exception; nested exception is java.lang.NoSuchFieldError: parallelCapableClassLoaderAvailable
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:587)

如果我对@EnableJpaRepositories注释进行注释，我会出现以下错误：

Unsatisfied dependency expressed through field 'userServiceImpl'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userServiceImpl': Unsatisfied dependency expressed through field 'usersRepository'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'ru.testproject.db.hibernate.repository.UsersRepository' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

在第二个场景中，存储库当然是空的——JPA回购被禁用。。求求你，救命！我做错了什么，我怎样才能让它起作用？我无法用谷歌和互联网解决我的问题。也许是因为我不明白根本问题是什么。

共有2个答案

太叔逸春

2023-03-14

您似乎没有在组件扫描中添加测试包ru.testproject.db.hibernate.repository。

孔乐邦

2023-03-14

谢谢大家的帮助！我通过以下更改解决了我的问题：1）首先，我用更新的版本更新了spring上下文依赖关系：

<dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>5.0.4.RELEASE</version>
    </dependency>

它解决了java问题。lang.NoClassDefFoundError:org/springframework/context/index/candidateComponents索引加载程序错误。候选组件索引加载器出现在spring context 5.0.0之后。

2）我添加了

@EnableJpaRepositories(basePackages = {
        "ru.testproject.hibernate"
})
@PropertySource("classpath:testproject.properties")
@ComponentScan("ru.testproject.hibernate")

注释。之前的变化没有影响到任何积极的变化。1）导致entityManagerFactory错误，我可以用以下方法解决：

3）为entityManagerFactory设置packgeToScan

entityManagerFactoryBean.setPackagesToScan("ru.testproject.hibernate.entity");

带有实体路径（在这种情况下为用户）。

仅此而已。现在存储库工作得很好。谢谢大家！！！

ps：可能吧，现在我可以从spring boot开始了）

如何在没有Spring Boot的情况下使用JPA存储库

共有2个答案

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