Spring Boot also provides a utility builder class DataSourceBuilder that can be used to create one of the standard data sources (if it is on the classpath). The builder can detect the one to use based on what’s available on the classpath. It also auto detects the driver based on the JDBC url.

@Bean
@ConfigurationProperties("app.datasource")
public DataSource dataSource() {
    return DataSourceBuilder.create().build();
}

https://docs.spring.io/spring-boot/docs/1.5.8.RELEASE/reference/htmlsingle/#boot-features-external-config-3rd-party-configuration