SpringBoot+JPA集成项目

最新推荐文章于 2025-03-02 14:31:28 发布

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本文介绍如何在Spring Boot项目中配置多数据源，并通过JPA进行数据库操作。包括Maven依赖配置、多数据源配置、实体类定义、Repository接口编写等关键步骤。

以前一直使用的都是mybatis（mybatis-plus）框架操作数据库。前一端时间有个朋友问了一下JPA查询统计后结果集不是一个实体该怎么接收处理的问题？
首先创建maven项目引入下面依赖：pom.xml

<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">
    <modelVersion>4.0.0</modelVersion>
    <!-- Inherit defaults from Spring Boot -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.5.RELEASE</version>
    </parent>
    <artifactId>study-5-domain</artifactId>  
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency> 
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        <!-- 热部署 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>

        <!-- 测试包,当我们使用 mvn package 的时候该包并不会被打入,因为它的生命周期只在 test 之内 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- 简化简单实体getter,setter -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

创建配置文件application.yml。示例：

spring:
  datasource:
    jdbc-url: jdbc:mysql://127.0.0.1:3306/db_comm_01?useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: root
    password: Root1234
    driver-class-name: com.mysql.jdbc.Driver 
  member: 
    datasource:  
      jdbc-url: jdbc:mysql://127.0.0.1:3306/db_member_01?useUnicode=true&characterEncoding=utf-8&useSSL=false
      username: root
      password: Root1234
      driver-class-name: com.mysql.jdbc.Driver 
  jpa: 
    database-platform: org.hibernate.dialect.MySQL5Dialect 
    show-sql: true 
    hibernate: 
      #不自动创建表。
      ddl-auto: none

多数据源配置。
DataSourseConfig.java注入数据源

/**
 * <p>数据源配置<p>
 * @Author Bertram.Wang
 * @Date 2019年3月30日
 */
@Configuration
public class DataSourceConfig {
    @Bean("dsComm")
    @Primary
    @ConfigurationProperties(prefix = "spring.datasource")
    public DataSource dataSource(){
        return DataSourceBuilder.create().build();
    }
    @Bean("dsMember")
    @ConfigurationProperties(prefix = "spring.member.datasource")
    public DataSource dataSourceSlave(){
        return DataSourceBuilder.create().build();
    } 
}

多个数据源只需要分开设置entityManager， transactionManager即可。分别创建CommDataSourceConfig.java,

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "entityManagerFactoryComm",//配置连接工厂 entityManagerFactory
        transactionManagerRef = "transactionManagerComm", //配置 事物管理器  transactionManager
        basePackages = {"bertram.springcloud.study.repository.comm"}
)
@SuppressWarnings({"rawtypes", "unchecked"})
public class CommDataSourceConfig {
    @Autowired
    @Qualifier("dsComm")
    private DataSource dataSourceMaster;
    @Autowired
    private JpaProperties jpaProperties;

    @Bean("entityManagerComm")
    @Primary
    public EntityManager entityManagerComm(EntityManagerFactoryBuilder builder) {
        return entityManagerFactoryComm(builder).getObject().createEntityManager();
    }
    @Bean("entityManagerFactoryComm")
    @Primary
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryComm(EntityManagerFactoryBuilder builder) {
        return builder.dataSource(dataSourceMaster)
                .properties(getVendorProperties())
                .packages("bertram.springcloud.study.entity.comm")
                .persistenceUnit("commPersistenceUnit")
                .build();

    }
    private Map getVendorProperties() {
        HibernateSettings hibernateSettings = new HibernateSettings();
        return jpaProperties.getHibernateProperties(hibernateSettings);
    }
    @Bean("transactionManagerComm")
    @Primary
    public PlatformTransactionManager transactionManagerComm(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactoryComm(builder).getObject());
    }
}

MemberDataSourceConfig.java

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "entityManagerFactoryMember",//配置连接工厂 entityManagerFactory
        transactionManagerRef = "transactionManagerMember", //配置 事物管理器  transactionManager
        basePackages = {"bertram.springcloud.study.repository.member"}
)
@SuppressWarnings({"rawtypes", "unchecked"})
public class MemberDataSourceConfig {

    @Autowired
    @Qualifier("dsMember")
    private DataSource dataSource;
    @Autowired
    private JpaProperties jpaProperties;
    @Bean("entityManagerFactoryMember")
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryMember(EntityManagerFactoryBuilder builder) {
        return builder.dataSource(dataSource)
                .properties(getVendorProperties())
                .packages("bertram.springcloud.study.entity.member")
                .build();
    }


    @Bean("entityManagerMember")
    public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
        return entityManagerFactoryMember(builder).getObject().createEntityManager();
    }

    @Bean("transactionManagerMember")
    public PlatformTransactionManager transactionManager(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactoryMember(builder).getObject());
    }

    private Map getVendorProperties() {
        HibernateSettings hibernateSettings = new HibernateSettings();
        return jpaProperties.getHibernateProperties(hibernateSettings);
    }
}

即可。

对应的repository写在对应的包下面就能分别识别数据源了。

具体文档结构

repository示例：

@Repository
public interface UserRepository extends JpaRepository<User, Integer> {
    User findOneById(Integer id);
}
@Repository
public interface MemberRepository extends JpaRepository<Member, Integer> {
    Member findOneById(Integer id);
}

实体类

@Data
@AllArgsConstructor
@NoArgsConstructor
@ToString
@EqualsAndHashCode(callSuper=false)
@Entity
@Table(name="sys_user")
public class User implements Serializable {
    private static final long serialVersionUID = -7643897007130979275L;
    @Id
    private Integer id;
    private Date createDate;
    private Date modifyDate;
    private String name;
    private String password;
}
@Data
@NoArgsConstructor
@AllArgsConstructor
@ToString
@EqualsAndHashCode(callSuper=false)
@Entity
@Table(name="member")
public class Member implements Serializable {
    private static final long serialVersionUID = -42305693425865718L;
    @Id
    private Integer id;
    private Date createDate;
    private Date modifyDate;
    private String name;
    private String phone;
    private String password;
}

数据库表：

数据库表

测试：

@RunWith(SpringRunner.class)   
@SpringBootTest(classes={Application.class})// 指定启动类
public class ApplicationTest {
    private static final Logger log = LoggerFactory.getLogger(ApplicationTest.class);
    @Autowired
    UserRepository userRepository;
    @Autowired
    MemberRepository memberRepository;
    @Test
    public void test() {
        User user = userRepository.findOneById(1);
        Member member = memberRepository.findOneById(1);
        log.info("user:{}", user);
        log.info("member:{}", member);
    }
}

执行结果：

执行日志

当我们查询的结果集和实体无对应的时候。
1：直接创建map接收。
示例：

@Query(value="SELECT u.id AS user_id, u.name AS user_name, u.password AS user_password, r.id AS role_id, r.name AS role_name FROM sys_user u LEFT JOIN sys_user_role ur ON ur.user_id = u.id LEFT JOIN sys_role r ON ur.role_id = r.id WHERE u.id = ?1", nativeQuery=true)
Map<String, Object> findOneByUserId(Integer userId);

2：创建一个vo类接收：
示例：

@Data
@NoArgsConstructor
@AllArgsConstructor
@Entity
public class UserRoleTest {
    @Id
    private Integer userId;
    private String userName;
    private String userPassword;
    private Integer roleId;
    private String roleName;
}


@Repository
public interface UserRoleTestRepository extends JpaRepository<UserRoleTest, Integer> {
    @Query(value="SELECT u.id AS user_id, u.name AS user_name, u.password AS user_password, r.id AS role_id, r.name AS role_name FROM sys_user u LEFT JOIN sys_user_role ur ON ur.user_id = u.id LEFT JOIN sys_role r ON ur.role_id = r.id WHERE u.id = ?1", nativeQuery=true)
    UserRoleTest findOneByUserId(Integer userId);
}

测试：

@Test
public void userRoleTest() throws Exception {
    UserRoleTest userRoleTest = userRoleTestRepository.findOneByUserId(1);
    Map<String, Object> map = userRepository.findOneByUserId(1);
    log.info("userRoleTest:{}", userRoleTest);
    log.info("map:{}",new ObjectMapper().writeValueAsString(map));
}

执行结果：