java多数据源查看当前数据源 springdatajpa多数据源

SpringDataJpa使用单数据源时的SpringBoot配置很简单，但是随着业务量发展，单个数据库可能不能满足我们的业务需求，这时候一般会对数据库进行拆分或引入其他数据库，此时单数据源就不能满足我们的需求，需要配置多个数据源。

在使用SpringBoot2.x进行SpringDataJpa多数据源配置之前，对SpringBoot2.x集成SpringDataJpa还不熟悉的朋友，可以先参考SpringBoot2.x 集成 SpringDataJpa。下面就开始进行SpringDataJpa多数据源配置及使用，其中SpringBoot使用的2.2.2.RELEASE版本，添加依赖在这里就不再表述了。

一、编写配置文件

在application.yml中进行如下配置：

spring:
  # 多数据源数据库连接配置
  datasource:
    # 第一数据源配置
    primary:
      jdbc-url: jdbc:mysql://127.0.0.1:3306/test1?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true
      driver-class-name: com.mysql.cj.jdbc.Driver
      username: root
      password: root
    # 第二数据源配置
    secondary:
      jdbc-url: jdbc:mysql://127.0.0.1:3306/test2?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true
      driver-class-name: com.mysql.cj.jdbc.Driver
      username: root
      password: root
  # jpa相关配置
  jpa:
    database: mysql
    show-sql: true
    generate-ddl: true
    hibernate:
      ddl-auto: update
    database-platform: org.hibernate.dialect.MySQL5InnoDBDialect

二、编写多数据源的配置类

1.多数据源配置类

package com.rtxtitanv.config;

import org.springframework.boot.autoconfigure.orm.jpa.HibernateProperties;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateSettings;
import org.springframework.boot.autoconfigure.orm.jpa.JpaProperties;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;

import javax.annotation.Resource;
import javax.sql.DataSource;
import java.util.Map;

/**
 * @author rtxtitanv
 * @version 1.0.0
 * @name com.rtxtitanv.config.DataSourceConfig
 * @description 多数据源配置类
 * @date 2020/1/7 19:19
 */
@Configuration
public class DataSourceConfig {

    @Resource
    private JpaProperties jpaProperties;
    @Resource
    private HibernateProperties hibernateProperties;

    /**
     * 配置第一数据源
     *
     * @return 数据源
     */
    @Bean(name = "primaryDataSource")
    @Primary // 标识为主数据源
    // prefix：指定yml配置文件中配置项的前缀
    @ConfigurationProperties(prefix = "spring.datasource.primary")
    public DataSource primaryDataSource() {
        // 这种方式默认只满足spring的配置方式，如果使用其他数据库连接池，需独立获取配置
        return DataSourceBuilder.create().build();
    }

    /**
     * 配置第二数据源
     *
     * @return 数据源
     */
    @Bean(name = "secondaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.secondary")
    public DataSource secondaryDataSource() {
        return DataSourceBuilder.create().build();
    }

    /**
     * 配置 组合jpaProperties和hibernateProperties配置的map对象
     *
     * @return 组合jpaProperties和hibernateProperties配置的map
     */
    @Bean(name = "vendorProperties")
    public Map<String, Object> getVendorProperties() {
        return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(), new HibernateSettings());
    }
}

2.第一数据源配置类

package com.rtxtitanv.config;

import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.annotation.Resource;
import javax.persistence.EntityManager;
import javax.sql.DataSource;
import java.util.Map;

/**
 * @author rtxtitanv
 * @version 1.0.0
 * @name com.rtxtitanv.config.PrimaryConfig
 * @description 第一数据源配置类
 * @date 2020/1/7 19:21
 */
@Configuration
@EnableTransactionManagement
// entityManagerFactoryRef：指定实体管理器工厂，transactionManagerRef：指定事务管理器
// basePackages：指定该数据源的repository所在包路径
@EnableJpaRepositories(entityManagerFactoryRef = "entityManagerFactoryPrimary",
    transactionManagerRef = "transactionManagerPrimary", basePackages = {"com.rtxtitanv.repository.primary"})
public class PrimaryConfig {

    @Resource(name = "primaryDataSource")
    private DataSource primaryDataSource;
    @Resource(name = "vendorProperties")
    private Map<String, Object> vendorProperties;

    /**
     * 配置第一数据源实体管理工厂的bean
     *
     * @param builder EntityManagerFactoryBuilder
     * @return LocalContainerEntityManagerFactoryBean
     */
    @Bean(name = "entityManagerFactoryPrimary")
    @Primary // 标识为主数据源（主库对应的数据源）
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryPrimary(EntityManagerFactoryBuilder builder) {
        return builder.dataSource(primaryDataSource)
            // 指定组合jpaProperties和hibernateProperties配置的map对象
            .properties(vendorProperties)
            // 指定该数据源的实体类所在包路径
            .packages("com.rtxtitanv.model.primary").persistenceUnit("primaryPersistenceUnit").build();
    }

    /**
     * 配置第一数据源实体管理器
     *
     * @param builder EntityManagerFactoryBuilder
     * @return EntityManager
     */
    @Bean(name = "entityManagerPrimary")
    @Primary
    public EntityManager entityManagerPrimary(EntityManagerFactoryBuilder builder) {
        return entityManagerFactoryPrimary(builder).getObject().createEntityManager();
    }

    /**
     * 配置第一数据源事务管理器
     *
     * @param builder EntityManagerFactoryBuilder
     * @return PlatformTransactionManager
     */
    @Bean(name = "transactionManagerPrimary")
    @Primary
    public PlatformTransactionManager transactionManagerPrimary(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactoryPrimary(builder).getObject());
    }
}

3.第二数据源配置类

package com.rtxtitanv.config;

import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.annotation.Resource;
import javax.persistence.EntityManager;
import javax.sql.DataSource;
import java.util.Map;

/**
 * @author rtxtitanv
 * @version 1.0.0
 * @name com.rtxtitanv.config.SecondaryConfig
 * @description 第二数据源配置类
 * @date 2020/1/7 19:21
 */
@Configuration
@EnableTransactionManagement
// entityManagerFactoryRef：指定实体管理器工厂，transactionManagerRef：指定事务管理器
// basePackages：指定该数据源的repository所在包路径
@EnableJpaRepositories(entityManagerFactoryRef = "entityManagerFactorySecondary",
    transactionManagerRef = "transactionManagerSecondary", basePackages = {"com.rtxtitanv.repository.secondary"})
public class SecondaryConfig {

    @Resource(name = "secondaryDataSource")
    private DataSource secondaryDataSource;
    @Resource(name = "vendorProperties")
    private Map<String, Object> vendorProperties;

    /**
     * 配置第二数据源实体管理工厂的bean
     *
     * @param builder EntityManagerFactoryBuilder
     * @return LocalContainerEntityManagerFactoryBean
     */
    @Bean(name = "entityManagerFactorySecondary")
    public LocalContainerEntityManagerFactoryBean entityManagerFactorySecondary(EntityManagerFactoryBuilder builder) {
        return builder.dataSource(secondaryDataSource)
            // 指定组合jpaProperties和hibernateProperties配置的map对象
            .properties(vendorProperties)
            // 指定该数据源的实体类所在包路径
            .packages("com.rtxtitanv.model.secondary").persistenceUnit("secondaryPersistenceUnit").build();
    }

    /**
     * 配置第二数据源实体管理器
     *
     * @param builder EntityManagerFactoryBuilder
     * @return EntityManager
     */
    @Bean(name = "entityManagerSecondary")
    public EntityManager entityManagerSecondary(EntityManagerFactoryBuilder builder) {
        return entityManagerFactorySecondary(builder).getObject().createEntityManager();
    }

    /**
     * 配置第二数据源事务管理器
     *
     * @param builder EntityManagerFactoryBuilder
     * @return PlatformTransactionManager
     */
    @Bean(name = "transactionManagerSecondary")
    public PlatformTransactionManager transactionManagerSecondary(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactorySecondary(builder).getObject());
    }
}

三、创建实体类和Repository

1.主数据库实体类

package com.rtxtitanv.model.primary;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;

import javax.persistence.*;

/**
 * @author rtxtitanv
 * @version 1.0.0
 * @name com.rtxtitanv.model.primary.PrimaryUser
 * @description 主数据库用户实体类
 * @date 2020/1/7 19:31
 */
@Accessors(chain = true)
@AllArgsConstructor
@NoArgsConstructor
@Data
@Entity
@Table(name = "user")
public class PrimaryUser {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;
    @Column(name = "user_name")
    private String userName;
    @Column(name = "pass_word")
    private String passWord;
    @Column(name = "nick_name")
    private String nickName;
    @Column(name = "age")
    private Integer age;
    @Column(name = "email")
    private String email;
    @Column(name = "tel")
    private String tel;
}

2.主数据库Repository

/**
 * @author rtxtitanv
 * @version 1.0.0
 * @name com.rtxtitanv.repository.primary.PrimaryUserRepository
 * @description PrimaryUserRepository接口用于操作主库用户表
 * @date 2020/1/7 19:34
 */
public interface PrimaryUserRepository extends JpaRepository<PrimaryUser, Long>, JpaSpecificationExecutor<PrimaryUser> {
}

3.从数据库实体类

package com.rtxtitanv.model.secondary;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;

import javax.persistence.*;

/**
 * @author rtxtitanv
 * @version 1.0.0
 * @name com.rtxtitanv.model.secondary.SecondaryUser
 * @description 从数据库用户实体类
 * @date 2020/1/7 19:32
 */
@Accessors(chain = true)
@AllArgsConstructor
@NoArgsConstructor
@Data
@Entity
@Table(name = "user")
public class SecondaryUser {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;
    @Column(name = "user_name")
    private String userName;
    @Column(name = "pass_word")
    private String passWord;
    @Column(name = "nick_name")
    private String nickName;
    @Column(name = "age")
    private Integer age;
    @Column(name = "email")
    private String email;
    @Column(name = "tel")
    private String tel;
}

4.从数据库Repository

/**
 * @author rtxtitanv
 * @version 1.0.0
 * @name com.rtxtitanv.repository.secondary.SecondaryUserRepository
 * @description SecondaryUserRepository用于操作从库用户表
 * @date 2020/1/7 19:37
 */
public interface SecondaryUserRepository extends JpaRepository<SecondaryUser, Long>, JpaSpecificationExecutor<SecondaryUser> {
}

四、使用测试

package com.rtxtitanv;

import com.rtxtitanv.model.primary.PrimaryUser;
import com.rtxtitanv.model.secondary.SecondaryUser;
import com.rtxtitanv.repository.primary.PrimaryUserRepository;
import com.rtxtitanv.repository.secondary.SecondaryUserRepository;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import java.util.List;
import java.util.Optional;

/**
 * @author rtxtitanv
 * @version 1.0.0
 * @name com.rtxtitanv.JpaMultiTest
 * @description SpringDataJpa多数据源测试类
 * @date 2020/1/7 18:22
 */
@RunWith(SpringRunner.class)
@SpringBootTest(classes = JpaMultiApplication.class)
public class JpaMultiTest {

    @Autowired
    private PrimaryUserRepository primaryUserRepository;
    @Autowired
    private SecondaryUserRepository secondaryUserRepository;
    private static Logger logger = LoggerFactory.getLogger(JpaMultiTest.class);

    /**
     * 多数据源保存测试
     */
    @Test
    public void saveTest() {
        primaryUserRepository.save(new PrimaryUser(null, "aaa", "123456", "aaa", 20, "[e-mail]", "13598766131"));
        primaryUserRepository.save(new PrimaryUser(null, "bbb", "123123", "bbb", 22, "[e-mail]", "13659836782"));
        primaryUserRepository.save(new PrimaryUser(null, "ccc", "111111", "ccc", 25, "[e-mail]", "18965233695"));
        secondaryUserRepository.save(new SecondaryUser(null, "ddd", "2356890", "ccc", 18, "[e-mail]", "13678922986"));
        secondaryUserRepository.save(new SecondaryUser(null, "eee", "124678", "bbb", 25, "[e-mail]", "13669876321"));
        secondaryUserRepository.save(new SecondaryUser(null, "fff", "112233567", "aaa", 22, "[e-mail]", "19862398732"));
    }

    /**
     * 多数据源查询测试
     */
    @Test
    public void findTest() {
        logger.info("查询主库user表测试开始");
        List<PrimaryUser> primaryUsers = primaryUserRepository.findAll();
        if (primaryUsers.isEmpty()) {
            logger.info("主库user表不存在数据");
        } else {
            primaryUsers.forEach(primaryUser -> logger.info(primaryUser.toString()));
        }
        logger.info("查询主库user表测试结束");
        logger.info("查询从库user表测试开始");
        List<SecondaryUser> secondaryUsers = secondaryUserRepository.findAll();
        if (secondaryUsers.isEmpty()) {
            logger.info("从库user表不存在数据");
        } else {
            secondaryUsers.forEach(secondaryUser -> logger.info(secondaryUser.toString()));
        }
        logger.info("查询从库user表测试结束");
    }

    /**
     * 多数据源更新测试
     */
    @Test
    public void updateTest() {
        Optional<PrimaryUser> user = primaryUserRepository.findById(1L);
        if (!user.isPresent()) {
            logger.info("用户不存在");
        } else {
            PrimaryUser primaryUser = user.get().setUserName("ddd").setNickName("ddd").setEmail("[e-mail]");
            primaryUserRepository.save(primaryUser);
        }
        Optional<SecondaryUser> user1 = secondaryUserRepository.findById(1L);
        if (!user1.isPresent()) {
            logger.info("用户记录不存在");
        } else {
            SecondaryUser secondaryUser = user1.get().setUserName("aaa").setNickName("aaa").setEmail("[e-mail]");
            secondaryUserRepository.save(secondaryUser);
        }
    }

    /**
     * 多数据源删除测试
     */
    @Test
    public void deleteTest() {
//        primaryUserRepository.deleteById(1L);
//        secondaryUserRepository.deleteById(3L);
        primaryUserRepository.deleteAllInBatch();
        secondaryUserRepository.deleteAllInBatch();
    }
 }

主启动类启动后，test1（主库）和test2（从库）都自动创建了一张user表，暂无数据。

执行保存测试方法后两张表的结果：

执行简单的查询测试后控制台打印的日志和自动生成的sql如下：

2020-01-08 16:38:14.342  INFO 10720 --- [           main] com.rtxtitanv.JpaMultiTest               : 查询主库user表测试开始
Hibernate: select primaryuse0_.id as id1_0_, primaryuse0_.age as age2_0_, primaryuse0_.email as email3_0_, primaryuse0_.nick_name as nick_nam4_0_, primaryuse0_.pass_word as pass_wor5_0_, primaryuse0_.tel as tel6_0_, primaryuse0_.user_name as user_nam7_0_ from user primaryuse0_
2020-01-08 16:38:14.487  INFO 10720 --- [           main] com.rtxtitanv.JpaMultiTest               : PrimaryUser(id=1, userName=aaa, passWord=123456, nickName=aaa, age=20, email=[e-mail], tel=13598766131)
2020-01-08 16:38:14.487  INFO 10720 --- [           main] com.rtxtitanv.JpaMultiTest               : PrimaryUser(id=2, userName=bbb, passWord=123123, nickName=bbb, age=22, email=[e-mail], tel=13659836782)
2020-01-08 16:38:14.487  INFO 10720 --- [           main] com.rtxtitanv.JpaMultiTest               : PrimaryUser(id=3, userName=ccc, passWord=111111, nickName=ccc, age=25, email=[e-mail], tel=18965233695)
2020-01-08 16:38:14.487  INFO 10720 --- [           main] com.rtxtitanv.JpaMultiTest               : 查询主库user表测试结束
2020-01-08 16:38:14.487  INFO 10720 --- [           main] com.rtxtitanv.JpaMultiTest               : 查询从库user表测试开始
Hibernate: select secondaryu0_.id as id1_0_, secondaryu0_.age as age2_0_, secondaryu0_.email as email3_0_, secondaryu0_.nick_name as nick_nam4_0_, secondaryu0_.pass_word as pass_wor5_0_, secondaryu0_.tel as tel6_0_, secondaryu0_.user_name as user_nam7_0_ from user secondaryu0_
2020-01-08 16:38:14.492  INFO 10720 --- [           main] com.rtxtitanv.JpaMultiTest               : SecondaryUser(id=1, userName=ddd, passWord=2356890, nickName=ccc, age=18, email=[e-mail], tel=13678922986)
2020-01-08 16:38:14.492  INFO 10720 --- [           main] com.rtxtitanv.JpaMultiTest               : SecondaryUser(id=2, userName=eee, passWord=124678, nickName=bbb, age=25, email=[e-mail], tel=13669876321)
2020-01-08 16:38:14.492  INFO 10720 --- [           main] com.rtxtitanv.JpaMultiTest               : SecondaryUser(id=3, userName=fff, passWord=112233567, nickName=aaa, age=22, email=[e-mail], tel=19862398732)
2020-01-08 16:38:14.493  INFO 10720 --- [           main] com.rtxtitanv.JpaMultiTest               : 查询从库user表测试结束

执行更新测试后控制台打印的sql语句如下，刷新两张表后查看更新成功。

Hibernate: select primaryuse0_.id as id1_0_0_, primaryuse0_.age as age2_0_0_, primaryuse0_.email as email3_0_0_, primaryuse0_.nick_name as nick_nam4_0_0_, primaryuse0_.pass_word as pass_wor5_0_0_, primaryuse0_.tel as tel6_0_0_, primaryuse0_.user_name as user_nam7_0_0_ from user primaryuse0_ where primaryuse0_.id=?
Hibernate: select primaryuse0_.id as id1_0_0_, primaryuse0_.age as age2_0_0_, primaryuse0_.email as email3_0_0_, primaryuse0_.nick_name as nick_nam4_0_0_, primaryuse0_.pass_word as pass_wor5_0_0_, primaryuse0_.tel as tel6_0_0_, primaryuse0_.user_name as user_nam7_0_0_ from user primaryuse0_ where primaryuse0_.id=?
Hibernate: update user set age=?, email=?, nick_name=?, pass_word=?, tel=?, user_name=? where id=?
Hibernate: select secondaryu0_.id as id1_0_0_, secondaryu0_.age as age2_0_0_, secondaryu0_.email as email3_0_0_, secondaryu0_.nick_name as nick_nam4_0_0_, secondaryu0_.pass_word as pass_wor5_0_0_, secondaryu0_.tel as tel6_0_0_, secondaryu0_.user_name as user_nam7_0_0_ from user secondaryu0_ where secondaryu0_.id=?
Hibernate: select secondaryu0_.id as id1_0_0_, secondaryu0_.age as age2_0_0_, secondaryu0_.email as email3_0_0_, secondaryu0_.nick_name as nick_nam4_0_0_, secondaryu0_.pass_word as pass_wor5_0_0_, secondaryu0_.tel as tel6_0_0_, secondaryu0_.user_name as user_nam7_0_0_ from user secondaryu0_ where secondaryu0_.id=?
Hibernate: update user set age=?, email=?, nick_name=?, pass_word=?, tel=?, user_name=? where id=?

执行删除测试后控制台打印的sql语句如下，刷新两张表查看删除成功。
按id删除：

Hibernate: select primaryuse0_.id as id1_0_0_, primaryuse0_.age as age2_0_0_, primaryuse0_.email as email3_0_0_, primaryuse0_.nick_name as nick_nam4_0_0_, primaryuse0_.pass_word as pass_wor5_0_0_, primaryuse0_.tel as tel6_0_0_, primaryuse0_.user_name as user_nam7_0_0_ from user primaryuse0_ where primaryuse0_.id=?
Hibernate: delete from user where id=?
Hibernate: select secondaryu0_.id as id1_0_0_, secondaryu0_.age as age2_0_0_, secondaryu0_.email as email3_0_0_, secondaryu0_.nick_name as nick_nam4_0_0_, secondaryu0_.pass_word as pass_wor5_0_0_, secondaryu0_.tel as tel6_0_0_, secondaryu0_.user_name as user_nam7_0_0_ from user secondaryu0_ where secondaryu0_.id=?
Hibernate: delete from user where id=?

删除所有：

Hibernate: delete from user
Hibernate: delete from user

代码示例

• Github：https://github.com/RtxTitanV/springboot-learning/tree/master/springboot2.x-learning/springboot-data-jpa-multi