JPA的多mysql數(shù)據(jù)源配置

• 1. 配置文件
     配置文件 application.yml 增加備用庫的設置如下：

spring:
  datasource:
    #    driver-class-name: com.mysql.jdbc.Driver  老版
    primary:
      driver-class-name: com.mysql.cj.jdbc.Driver
      username: root
      password: 12345678
      # 一定是jdbc-url 要不然報錯 數(shù)據(jù)源連接配置2.x和1.x的配置項是有區(qū)別的：2.x使用jdbc-url溃斋，
      # 而1.x版本使用 url铛碑。
      jdbc-url: jdbc:mysql://x.x.x.x:13306/your_primary_sql_name?charterEncoding=utf-8&useSSl=false&serverTimezone=Asia/Shanghai
    secondary:
      driver-class-name: com.mysql.cj.jdbc.Driver
      username: root
      password: 12345678
      jdbc-url: jdbc:mysql://y.y.y.y:13306/you_secondary_sql_name?charterEncoding=utf-8&useSSl=false&serverTimezone=Asia/Shanghai

注意：如果你在配置的時候發(fā)生了這個報錯java.lang.IllegalArgumentException: jdbcUrl is required with driverClassName. 就是url配置項錯誤非驮。2.x版本下吐句，url配置項名稱應該為jdbc-url。

• 2. 創(chuàng)建一個多數(shù)據(jù)源的配置類加載上述數(shù)據(jù)源配置
     比如我新建一個配置類：DataSourceConfig，內容如下：

@Configuration
public class DataSourceConfig {

    // @Primary注解指定了主數(shù)據(jù)源，就是當我們不特別指定哪個數(shù)據(jù)源的時候，就會使用這個Bean
    @Primary
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.primary")
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create().build();
    }

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

}

• 3. 數(shù)據(jù)源primary配置類
     新建數(shù)據(jù)源primary配置類：JpaConfigPrimary谤饭，內容如下：

@Configuration
/* 使用 @EnableTransactionManagement 注解來進行 JPA 的配置，該注解中主要配置了三個屬性：
   basePackages 用來指定 Repository 所在的位置（可以配置多個包）胖笛。
   entityManagerFactoryRef 用來指定實體類管理工廠 Bean 的名稱网持。
   transactionManagerRef 用來指定事物管理器的引用名稱，這里的引用名稱就是 JpaConfigOne 類中注冊的 Bean 的名稱（默認的 Bean 名稱為方法名）
 */
@EnableTransactionManagement
@EnableJpaRepositories(entityManagerFactoryRef="entityManagerFactoryPrimary",
        transactionManagerRef="transactionManagerPrimary",
        basePackages = {"com.tony.miaosuan.repository"})
public class JpaConfigPrimary {

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

    @Autowired
    private JpaProperties jpaProperties;
    @Autowired
    private HibernateProperties hibernateProperties;

    private Map<String, Object> getVendorProperties() {
        return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(), new HibernateSettings());
    }

    @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)
                .packages("com.tony.miaosuan.model")   //設置實體類所在位置
                .persistenceUnit("primaryPersistenceUnit")
                .properties(getVendorProperties())
                .build();
    }

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

}

• 4. 數(shù)據(jù)源secondary配置類
     新建數(shù)據(jù)源secondary配置類：JpaConfigSecondary长踊，內容如下：

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(entityManagerFactoryRef="entityManagerFactorySecondary",
        transactionManagerRef="transactionManagerSecondary",
        basePackages = {"com.tony.miaosuan.repository2"})
public class JpaConfigSencondary {

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

    @Autowired
    private JpaProperties jpaProperties;
    @Autowired
    private HibernateProperties hibernateProperties;

    private Map<String, Object> getVendorProperties() {
        return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(), new HibernateSettings());
    }

    @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)
                .packages("com.tony.miaosuan.model2")  //設置實體類所在位置
                .persistenceUnit("secondaryPersistenceUnit")
                .properties(getVendorProperties())
                .build();
    }

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