How to get a reference to currently active dataSource in Spring Boot

Defining DataSource in Spring

package com.javaskool.config;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.stream.Collectors;

import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
//import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PropertiesLoaderUtils;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;


@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
		entityManagerFactoryRef = "userEntityManager", 
		transactionManagerRef = "userTransactionManager", 
		basePackages = "com.javaskool.dao"
)
public class UserDBConfig {
	
	 @Autowired
	  private Environment env;

	@Bean
	@ConfigurationProperties(prefix = "spring.user.datasource")
	public DataSource postgresqlDataSource() {
		/*return DataSourceBuilder
					.create()
					.build();*/
		DriverManagerDataSource dataSource = new DriverManagerDataSource();
	    dataSource.setDriverClassName(env.getProperty("spring.user.datasource.driverClassName"));
	    dataSource.setUrl(env.getProperty("spring.user.datasource.url"));
	    dataSource.setUsername(env.getProperty("spring.user.datasource.username"));
	    dataSource.setPassword(env.getProperty("spring.user.datasource.password"));

	    return dataSource;
	}

	@Bean(name = "userEntityManager")
	public LocalContainerEntityManagerFactoryBean postgresqlEntityManagerFactory(EntityManagerFactoryBuilder builder) {
		return builder
					.dataSource(postgresqlDataSource())
					.properties(hibernateProperties())
					.packages("com.javaskool.domain")
					.persistenceUnit("js_user_PU")
					.build();
	}

	@Bean(name = "userTransactionManager")
	public PlatformTransactionManager postgresqlTransactionManager(@Qualifier("userEntityManager") EntityManagerFactory entityManagerFactory) {
		return new JpaTransactionManager(entityManagerFactory);
	}

	private Map hibernateProperties() {

		Resource resource = new ClassPathResource("hibernate.properties");
		
		try {
			Properties properties = PropertiesLoaderUtils.loadProperties(resource);
			
			return properties.entrySet().stream()
											.collect(Collectors.toMap(
														e -> e.getKey().toString(),
														e -> e.getValue())
													);
		} catch (IOException e) {
			return new HashMap();
		}
	}
}

Usage of DataSource

If you have a datasource already created as above it will be in the spring container, so you can call it as below

package com.javaskool.config;

import javax.sql.DataSource;
import org.springframework.context.annotation.Configuration;

@Configuration
public class GeneralServiceClass {

	
	@Autowired
	DataSource dataSource;
	//TODO
	
	public void  cleanupDatasource() throws Exception {		  
		  Connection connection = null;
		  try {
		    connection = dataSource.getConnection();
		    try {
		      Statement stmt = connection.createStatement();
		      try {
		        stmt.execute("TRUNCATE SCHEMA PUBLIC RESTART IDENTITY AND COMMIT NO CHECK");
		        connection.commit();
		        System.out.println("Schema truncated...");
		      } finally {
		        stmt.close();
		      }
		    } catch (SQLException e) {
		        connection.rollback();
		        throw new Exception(e);
		    }
		    } catch (SQLException e) {
		        throw new Exception(e);
		    } finally {
		        if (connection != null) {
		            connection.close();
		        }
		    }
		}
	
}

application.Properties

# Show all queries
spring.datasource.initialization-mode=always
spring.jpa.show-sql=false
spring.jpa.generate-ddl=true
spring.jpa.hibernate.ddl-auto=update
spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect

spring.user.datasource.driverClassName=com.mysql.jdbc.Driver
spring.user.datasource.url=jdbc:mysql://localhost:3306/my_db123
spring.user.datasource.username=root
spring.user.datasource.password=root@123
spring.user.datasource.driver-class-name=com.mysql.jdbc.Driver