mdeletecommand.java

基于Java的软件信息系统－项目管理

package cmd;

import core.*;
import db.*;
import java.util.List;
import java.util.ArrayList;
import javax.swing.JOptionPane;

public class MDeleteCommand extends MDatabaseCommand
{
    private static final String [] PARAM_NAMES =
    { "id" };
    private static final String [] PARAM_PROMPTS =
    { "Enter reservation id:" };

    public MDeleteCommand ()
	throws java.io.IOException
    {
	super ();
    }

    public String [] getParameterNames ()
    {
	return PARAM_NAMES;
    }
    
    public String [] getParameterPrompts ()
    {
	return PARAM_PROMPTS;
    }

    protected void executeDatabaseCommand (HotelDB database)
    {
	int id = Integer.parseInt (getParameter ("id"));
        // empty list value indicates that it worked
        String title = "Delete reservation: " + getParameter ("id");
	if (database.deleteReservation (id))
            displayResults (title, new ArrayList ());
        // null value indicates no such reservation
        else
            displayResults (title, null);
    }

    protected void displayResultsText (String title, List flag)
    {
        if (flag == null)
            System.out.println ("No such reservation");
        else
            System.out.println ("Reservation deleted.");
    }

    protected void displayResultsGUI (String title, List flag)
    {
        if (flag == null)
            JOptionPane.showMessageDialog(getFrame(), title, 
                                      "Delete Command Error. No such reservation.", 
                                      JOptionPane.ERROR_MESSAGE);
        else
            JOptionPane.showMessageDialog(getFrame(), title, 
                                      "Deleted Command Succeeded", 
                                      javax.swing.JOptionPane.INFORMATION_MESSAGE);
    }

    public String getMenuName ()
    { return "Delete..."; }
    public String getName ()
    { return "delete"; }
    public String getDescription ()
    { 
	return "Deletes a reservation by id"; 
    }
    public Command makeInstance ()
    {
	try
	{
	    return new MDeleteCommand ();
	} catch (java.io.IOException e)
	{
	    return null;
	}
    }
}