SpringBoot3+JPA+MySQL实现多数据源的读写分离(基于EntityManagerFactory)

@Configuration
public class DataSourceConfig {
 
    @Bean
    @Primary
    @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();
    }
 
    @Bean
    public JpaVendorAdapter jpaVendorAdapter() {
        return new HibernateJpaVendorAdapter();
    }
 
    @Bean(name = "entityManagerFactoryPrimary")
    @Primary
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryPrimary(
            EntityManagerFactoryBuilder builder,
            @Qualifier("primaryDataSource") DataSource primaryDataSource) {
        return builder
                .dataSource(primaryDataSource)
                .packages("com.yourcompany.yourapp.domain.primary") // Set package names of your entities
                .persistenceUnit("primary")
                .properties(jpaProperties())
                .build();
    }
 
    @Bean(name = "entityManagerFactorySecondary")
    public LocalContainerEntityManagerFactoryBean entityManagerFactorySecondary(
            EntityManagerFactoryBuilder builder,
            @Qualifier("secondaryDataSource") DataSource secondaryDataSource) {
        return builder
                .dataSource(secondaryDataSource)
                .packages("com.yourcompany.yourapp.domain.secondary") // Set package names of your entities
                .persistenceUnit("secondary")
                .properties(jpaProperties())
                .build();
    }
 
    private Map<String, Object> jpaProperties() {
        Map<String, Object> properties = new HashMap<>();
        properties.put("hibernate.dialect", "org.hibernate.dialect.MySQL5Dialect");
        // Add other JPA properties as needed
        return properties;
    }
 
    // ... 配置多个EntityManager
}

这个配置类定义了两个数据源（primary和secondary），并为每个数据源创建了一个LocalContainerEntityManagerFactoryBean实例。通过指定不同的包名来区分不同数据源的实体类。同时，它展示了如何配置JPA属性（例如方言）。在实际应用中，你需要将com.yourcompany.yourapp.domain.primary和com.yourcompany.yourapp.domain.secondary替换为实际实体类所在的包路径。