AppInitializer.java

package org.springframework.issues;

import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.jdbc.datasource.embedded.EmbeddedDatabase;
import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseBuilder;
import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType;
import org.springframework.transaction.PlatformTransactionManager;

import javax.sql.DataSource;

public class AppInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {

    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {

        ConfigurableListableBeanFactory beanFactory = applicationContext.getBeanFactory();

        DataSource dataSource = createDataSource();

        beanFactory.registerSingleton("dataSource", dataSource);

        beanFactory.registerSingleton("myTransactionManager", createPlatformTransactionManager(dataSource));

    }

    public DataSource createDataSource() {
        EmbeddedDatabase dataSource = new EmbeddedDatabaseBuilder().setType(EmbeddedDatabaseType.H2).build();
        return dataSource;
    }

    public PlatformTransactionManager createPlatformTransactionManager(DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

}