mdatabasecommand.java

来自「基于Java的软件信息系统－项目管理」· Java 代码 · 共 40 行

package core;

import core.Command;
import db.HotelDB;

import java.io.*;

public abstract class MDatabaseCommand extends Command
{
    private static final String DATABASE_FILENAME = "\\db\\reservations.dat";
    //    private static final String DATABASE_FILENAME =
    // 	"F:\\Personal\\courses\\w03\\is313\\hwk3\\solution\\db\\reservations.dat";
    //        private static final String DATABASE_FILENAME =
    //    	"C:\\Documents and Settings\\rburke\\My Documents\\courses\\w03\\hwk\\hwk3\\solution\\db\\reservations.dat";
    //    private static final String DATABASE_FILENAME =
    //    "C:\\Documents and Settings\\rburke\\My Documents\\courses\\win03\\is313\\hwk\\hwk3\\solution\\db\\reservations.dat";

    protected static HotelDB s_database;

    protected static HotelDB getDatabase ()
    {
	return s_database;
    }

    public MDatabaseCommand ()
	throws IOException
    {
	if (getDatabase () == null)
	    s_database = new HotelDB (DATABASE_FILENAME);
    }

    public void executeCommand ()
    {
	HotelDB db = getDatabase();
	executeDatabaseCommand (db);
    }

    protected abstract void executeDatabaseCommand (HotelDB database);
}