System.err.printf("[%s] establishing connection\n", System.currentTimeMillis());
c = oracleDataSource.getConnection();
System.err.printf("[%s] connection established\n", System.currentTimeMillis());
s = c.createStatement();
s.setQueryTimeout(1);
 
for (;;) {
    System.err.printf("[%s] executing query \n", System.currentTimeMillis());
    r = s.executeQuery("select 1 from dual");
    System.err.printf("[%s] query returned\n", System.currentTimeMillis());
    r.close();
    try { Thread.sleep(1000); } catch (InterruptedException e) { }
}