你可以使用ResultSet#getInt(int)来返回一个查询列的整数值，按照它的顺序（例如，第一列是1，第二列是2，等等）：

try (Connection con = /* connect to the database */;
     Statement s = conn.createStatement();
     ResultSet rs = s.executeQuery("select count(*) from employeedetails") {

     // This query returns at most only one row
     if (rs.next()) {
         int numEmployees = rs.getInt(1);
         // Do something with numEmployees
     }
}