spring boot Mybatis多数据源配置

关于

有时候，随着业务的发展，项目关联的数据来源会变得越来越复杂，使用的数据库会比较分散，这个时候就会采用多数据源的方式来获取数据。另外，多数据源也有其他好处，例如分布式数据库的读写分离，集成多种数据库等等。

下面分享我在实际项目中配置多数据源的案例。话不多说了，来一起看看详细的介绍吧

步骤

1.application.yml文件中，配置数据库源。这里primary是主库，secondary是从库。

 server:
  port: 8089

 # 多数据源配置
 #primary
 spring:
  primary:
  datasource:
   url: jdbc:mysql://127.0.0.1:3306/database1?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false&useLegacyDatetimeCode=false&serverTimezone=Asia/Shanghai
   username: root
   password: ******
   driver-class-name: com.mysql.jdbc.Driver

  #secondary
  secondary:
  datasource:
   url: jdbc:mysql://127.0.0.1:3306/database1?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false&useLegacyDatetimeCode=false&serverTimezone=Asia/Shanghai
   username: root
   password: ******
   driver-class-name: com.mysql.jdbc.Driver

  jpa:
  hibernate:
   primary-dialect: org.hibernate.dialect.MySQL5Dialect
   secondary-dialect: org.hibernate.dialect.MySQL5Dialect
  open-in-view: true
  show-sql: true

application.yml

2.创建一个Spring配置类，其中spring.primary.datasource的路径参考yml文件的配置。

 @Configuration
 public class DataSourceConfig {

  @Bean(name = "primaryDataSource")
  @Qualifier("primaryDataSource")
  @ConfigurationProperties(prefix="spring.primary.datasource")
  public DataSource primaryDataSource() {
   return DataSourceBuilder.create().build();
  }

  @Bean(name = "secondaryDataSource")
  @Qualifier("secondaryDataSource")
  @Primary
  @ConfigurationProperties(prefix="spring.secondary.datasource")
  public DataSource secondaryDataSource() {
   return DataSourceBuilder.create().build();
  }

 }

DataSourceConfig

3.分别创建主库、从库的配置类。

注意：entity包和dao包的配置，以及@Primary注解指定主库。

主库配置类：

 @Configuration
 @EnableTransactionManagement
 @EnableJpaRepositories(
   entityManagerFactoryRef = "entityManagerFactoryPrimary",
   transactionManagerRef = "transactionManagerPrimary",
   basePackages = {"com.infinitus.yunxiao_data.dao.primary"}) //设置Repository所在位置
 public class PrimaryConfig {
  @Autowired
  private JpaProperties jpaProperties;

  @Autowired
  @Qualifier("primaryDataSource")
  private DataSource primaryDataSource;

  @Primary
  @Bean(name = "entityManagerPrimary")
  public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
   return entityManagerFactoryPrimary(builder).getObject().createEntityManager();
  }

  @Primary
  @Bean(name = "entityManagerFactoryPrimary")
  public LocalContainerEntityManagerFactoryBean entityManagerFactoryPrimary(EntityManagerFactoryBuilder builder) {
   return builder
     .dataSource(primaryDataSource)
     .properties(getVendorProperties(primaryDataSource))
     .packages("com.infinitus.yunxiao_data.entity.primary") //设置实体类所在位置
     .persistenceUnit("primaryPersistenceUnit")
     .build();
  }

  private Map getVendorProperties(DataSource dataSource) {
   return jpaProperties.getHibernateProperties(dataSource);
  }

  @Primary
  @Bean(name = "transactionManagerPrimary")
  public PlatformTransactionManager transactionManagerPrimary(EntityManagerFactoryBuilder builder) {
   return new JpaTransactionManager(entityManagerFactoryPrimary(builder).getObject());
  }
 }

主库配置

从库的配置类：

 @Configuration
 @EnableTransactionManagement
 @EnableJpaRepositories(
   entityManagerFactoryRef = "entityManagerFactorySecondary",
   transactionManagerRef = "transactionManagerSecondary",
   basePackages = {"com.infinitus.yunxiao_data.dao.secondary"}) //设置Repository所在位置
 public class SecondaryConfig {
  @Autowired
  private JpaProperties jpaProperties;

  @Autowired
  @Qualifier("secondaryDataSource")
  private DataSource secondaryDataSource;

  @Bean(name = "entityManagerSecondary")
  public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
   return entityManagerFactorySecondary(builder).getObject().createEntityManager();
  }

  @Bean(name = "entityManagerFactorySecondary")
  public LocalContainerEntityManagerFactoryBean entityManagerFactorySecondary(EntityManagerFactoryBuilder builder) {
   return builder
     .dataSource(secondaryDataSource)
     .properties(getVendorProperties(secondaryDataSource))
     .packages("com.infinitus.yunxiao_data.entity.secondary") //设置实体类所在位置
     .persistenceUnit("primaryPersistenceUnit")
     .build();
  }

  private Map getVendorProperties(DataSource dataSource) {
   return jpaProperties.getHibernateProperties(dataSource);
  }

  @Bean(name = "transactionManagerSecondary")
  PlatformTransactionManager transactionManagerSecondary(EntityManagerFactoryBuilder builder) {
   return new JpaTransactionManager(entityManagerFactorySecondary(builder).getObject());
  }

 }

从库配置

4.分别创建主、从库dao类。

主dao：

 @Repository
 public interface PrimaryRepository extends JpaRepository<PrimaryEntity, Long> {

  @Query(value = "SELECT p FROM PrimaryEntity p")
  List<PrimaryEntity> queryList();

 }

主dao

从dao：

 @Repository
 public interface SecondaryRepository extends JpaRepository<SecondaryEntity, Long> {

  @Query(value = "SELECT p FROM SecondaryEntity p")
  List<SecondaryEntity> queryList();

 }

从dao

5.分别创建主、从库entity类。

主entity：

 @Entity
 @Table(name = "holiday_scheme")
 @EntityListeners(AuditingEntityListener.class)
 public class PrimaryEntity extends AbstractPersistable<Long> {
  @Column(name = "date")
  public String date;
  @Column(name = "hour")
  public String hour;
  @Column(name = "holiday")
  public String holiday;
  @Column(name = "holiday_explain")
  public String holiday_explain;

  public String getDate() {
   return date;
  }

  public void setDate(String date) {
   this.date = date;
  }

  public String getHour() {
   return hour;
  }

  public void setHour(String hour) {
   this.hour = hour;
  }

  public String getHoliday() {
   return holiday;
  }

  public void setHoliday(String holiday) {
   this.holiday = holiday;
  }

  public String getHoliday_explain() {
   return holiday_explain;
  }

  public void setHoliday_explain(String holiday_explain) {
   this.holiday_explain = holiday_explain;
  }

  @Override
  public String toString() {
   return "PrimaryEntity{" +
     "date='" + date + '\'' +
     ", hour='" + hour + '\'' +
     ", holiday='" + holiday + '\'' +
     ", holiday_explain='" + holiday_explain + '\'' +
     '}';
  }
 }

主Entity

从entity：

 @Entity
 @Table(name = "active_dashboards")
 @EntityListeners(AuditingEntityListener.class)
 public class SecondaryEntity extends AbstractPersistable<Long> {

  @Column(name = "dashboard_id")
  public String dashboard_id;
  @Column(name = "user_id")
  public String user_id;
  @Column(name = "order_index")
  public String order_index;

  public String getDashboard_id() {
   return dashboard_id;
  }

  public void setDashboard_id(String dashboard_id) {
   this.dashboard_id = dashboard_id;
  }

  public String getUser_id() {
   return user_id;
  }

  public void setUser_id(String user_id) {
   this.user_id = user_id;
  }

  public String getOrder_index() {
   return order_index;
  }

  public void setOrder_index(String order_index) {
   this.order_index = order_index;
  }

  @Override
  public String toString() {
   return "SecondaryEntity{" +
     "dashboard_id='" + dashboard_id + '\'' +
     ", user_id='" + user_id + '\'' +
     ", order_index='" + order_index + '\'' +
     '}';
  }
 }

从Entity

6.controller请求获取不同数据库的数据。

 @RestController
 @RequestMapping("/database")
 public class MailController {
  private final Logger logger = LoggerFactory.getLogger(this.getClass());

  @Autowired
  PrimaryRepository primaryRepository;
  @Autowired
  SecondaryRepository secondaryRepository;

  @RequestMapping("/primary")
  @ResponseBody
  public String primary() {
   return primaryRepository.queryList().toString();
  }

  @RequestMapping("/secondary")
  @ResponseBody
  public String secondary() {
   return secondaryRepository.queryList().toString();
  }

 }

Controller

注意

下面提两个在配置多数据源时遇到的坑点，一不注意就掉坑了。

1.Application类不需要配置@EnableJpaRepositories注解，会报如下错误。

A component required a bean named 'entityManagerFactory' that could not be f

2.注意检查dao类，获取数据的方法上格式是否正确，有没有某个字段是表中不存在的，避免启动异常。如下，SecondaryEntity表中是不存在job_name字段的，所以注释掉才能启动成功等。

 //@Query(value = "SELECT p FROM SecondaryEntity p where p.job_name = ?1")
 //List<SecondaryEntity> queryOdcRecord(String job_name);

转自：http://blog.csdn.net/yuechang5/article/details/53471743

https://baomidou.oschina.io/mybatis-plus-doc/#/multi-datasource

https://blog.csdn.net/husong_/article/details/80103497

https://www.cnblogs.com/hdwang/p/7041096.html

https://www.jb51.net/article/154301.htm