JPA entityManager如何在Spring Boot Application中选择Connection Pool？

Question

I have 2 DAO - the first works with @Bean DataSource + JDBC . Configuration is the following:

@Bean("dataSource")
    @Singleton
    public DataSource getDataSource() {
        BasicDataSource basicDataSource = new BasicDataSource();
        basicDataSource.setDriverClassName("...");
        basicDataSource.setUrl("...");
        basicDataSource.setUsername(...);
        basicDataSource.setPassword(...);
        ...
        return basicDataSource;
    }

The second works with entityManager . application.properties configuration is the following:

spring.datasource.url=...
spring.datasource.username=...
spring.datasource.password=...
...

When I starts my Spring Boot Application and spring initializes my beans , I use the second DAO to get some information from database .

I am using second DAO -> entityManager in this case.

I expects that entityManager uses configuration from application.properties .
Indeed, entityManager uses configration from bean DataSource .

How does It work?
ps database properties in application.properties look like used.

Actually I think that I should use one ConnectionPool for my application.
I can configure DataSource as @Bean and provide entityManager and jdbcTemplate with It.
Should I choose another solution? Or Is this idea quite suitable?

Answer 1

It's because of the importance. @Configuration has higher precedence than application.properties. First spring-boot searches for @Bean definition, if it's not found, then it checks application.properties. Generally those definitions are equivalent.