private HikariDataSource dataSource() {
final HikariDataSource ds = new HikariDataSource();
ds.setMaximumPoolSize(100);
ds.setDriverClassName("oracle.jdbc.driver.OracleDriver");
ds.setJdbcUrl("jdbc:oracle:thin:@localhost:1521:XE"); ;
ds.setUsername("username");
ds.setPassword("password");
return ds;
}