import com.zaxxer.hikari.HikariDataSource;
private static HikariDataSource ds;

// Constructor
try {
    ds = new HikariDataSource();
    ds.setJdbcUrl("jdbc:mysql://localhost/tweets?useSSL=false&useUnicode=true");
    ds.setUsername("root");
    ds.setPassword("root");
    ds.setMaximumPoolSize(1000);
} catch (Exception e) {
    e.printStackTrace();
}


// When you need connection
Connection conn = ds.getConnection();
...