import java.util.Map;
public interface IEmployeeDAO {
  //SQL String that will be executed
  public String FIND_BY_SAL_RNG = "SELECT EMP_NO, EMP_NAME, "
  + "SALARY FROM EMP WHERE SALARY >= ? AND SALARY <= ?";

  //Returns the list of employees who fall into the given salary
  //range. The input parameter is the immutable map object
  //obtained from the HttpServletRequest. This is an early
  //refactoring based on "Introduce Parameter Object"

  public List findBySalaryRange(Map salaryMap);
}

 import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.List;
import java.util.ArrayList;
import java.util.Map;
import com.bea.dev2dev.to.EmployeeTO;

public class EmployeeDAOImpl implements IEmployeeDAO{

  public List findBySalaryRange(Map salaryMap)
  {
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    List empList = new ArrayList();
    //Transfer Object for inter-tier data transfer
    EmployeeTO tempEmpTO = null;
    try{
    //DBUtil - helper classes that retrieve connection from pool
      conn = DBUtil.getConnection();
      pstmt = conn.prepareStatement(FIND_BY_SAL_RNG);
      pstmt.setDouble(1, Double.valueOf( (String)
          salaryMap.get("MIN_SALARY") );
      pstmt.setDouble(2, Double.valueOf( (String)
          salaryMap.get("MIN_SALARY") );
      rs = pstmt.executeQuery();
      int tmpEmpNo = 0;
      String tmpEmpName = "";
      double tmpSalary = 0.0D;
      while (rs.next()){
        tmpEmpNo = rs.getInt("EMP_NO");
        tmpEmpName = rs.getString("EMP_NAME");
        tmpSalary = rs.getDouble("SALARY");
        tempEmpTO = new EmployeeTO(tmpEmpNo,
              tmpEmpName,
              tmpSalary);
        empList.add(tempEmpTO);
      }//end while
    }//end try
    catch (SQLException sqle){
      throw new DBException(sqle);
    }//end catch
    finally{
      try{
        if (rs != null){
          rs.close();
        }
      }
      catch (SQLException sqle){
        throw new DBException(sqle);
      }
      try{
        if (pstmt != null){
          pstmt.close();
        }
      }
      catch (SQLException sqle){
        throw new DBException(sqle);
      }
      try{
        if (conn != null){
          conn.close();
        }
      }
      catch (SQLException sqle){
        throw new DBException(sqle);
      }
    }//end of finally block
    return empList;
  }//end method findBySalaryRange
}