Does JdbcTemplate create a new connection every time you call query()?

Question

In the below example, does JdbcTemplate create two connections or one?

public class MyDao {

     private JdbcTemplate jdbcTemplate;

     public List<Data1> getData1() {
          return jdbcTemplate.query(mySql, myParams, myCallback);
     }

     public List<Data2> getData2() {
          jdbcTemplate.query(mySql2, myParams2, myCallback2);
     }
}

public class Main {
    public static void main(String[] args) {
         MyDao dao = new MyDao();
         List<Data1> d1 = dao.getData1();
         List<Data2> d2 = dao.getData2();
         doStuff(d1, d2);
    }
}

That is to say, does it reuse the connection from the first query? We are assuming that it was constructed with a basic data source (not a pooled data source).

Answer 1

It depends on the JdbcTempate's DataSource. If you provided a connection pool, like Apache commons-dbcp, then DBCP will do its best to reuse Connections. If you used Spring JDBC's DriverManagerDataSource a new Connection will be created / closed on each JdbcTemplate.query call.