Resource Annotation: No qualifying bean of type [javax.sql.DataSource] is defined: expected single matching bean but found 2

Question

I am using Spring Java Based configuration for configure multiple database with Spring Data. In the configuration file, i am creating two data source for MySQ

Answer 1

I had the same problem and after a lot of headache I stumbled upon this doc that made me feel really dumb :(

All you need is @Primary on one of your DataSources and Spring-Boot won't get confused anymore... Here is one of my configurations... The rest are pretty much identical, pointing to other DBs and with no @Primary on them...

@Configuration
@EnableTransactionManagement
@EntityScan(basePackages = {"somepackage.entities"})
@EnableJpaRepositories(entityManagerFactoryRef = "emfDB1", transactionManagerRef = "tmDB1", basePackages = {"somepackage.repositories"})
class PersistenceDB1 {
    @Bean
    @Primary
    DataSource dsDB1() {
        BasicDataSource dataSource = new BasicDataSource();
        dataSource.setUrl("jdbc:mysql://someserver:3306/proativo");
        dataSource.setUsername("username");
        dataSource.setPassword("password");
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        return dataSource;
    }

    @Bean
    @Primary
    LocalContainerEntityManagerFactoryBean emfDB1() {
        LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();
        entityManagerFactoryBean.setDataSource(dsDB1());
        entityManagerFactoryBean.setJpaVendorAdapter(new EclipseLinkJpaVendorAdapter());

        entityManagerFactoryBean.setPersistenceXmlLocation("classpath:META-INF/DB1-persistence.xml");

        Properties jpaProperties = new Properties();
        jpaProperties.put("eclipselink.weaving", "false");
        jpaProperties.put("eclipselink.logging.level", "SEVERE"); // SEVERE / FINEST

        entityManagerFactoryBean.setJpaProperties(jpaProperties);
        return entityManagerFactoryBean;
    }

    @Bean
    @Primary
    JpaTransactionManager tmDB1() {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(emfDB1().getNativeEntityManagerFactory());
        return transactionManager;
    }
}

Edit: Forgot to mention: Probably due to the way my configuration classes are done, the method of excluding some classes on @EnableAutoConfiguration didn't work for me...