dietbilltable.java

酒店管理系统

package javabean;
import java.util.*;

public class DietBillTable {
	int MAXFOODS = 50;
	

    /**
     * The Book hashtable stores all of the books in the 
     * library basket.  The key is the book isbn, the value 
     * stored is the quantity of that book. Initially, the 
     * Book hashtable has a size of 15 and a load factor of .75.
    */
    
    Hashtable DietBill = new Hashtable( 15, (float) .75 );
    int numberFood = 0;
    
    public DietBillTable(){}
    
    public void removeItem(String foodID){
    	Integer foodNumber;
    	foodNumber = (Integer)DietBill.get(foodID);
    	
    	if(foodNumber == null){return;}
    	
    	if(foodNumber.intValue()==1){
    		DietBill.remove(foodID);
    		numberFood--;
    	}else{
    		int tempQuant = foodNumber.intValue();
    		tempQuant--;
    		DietBill.remove( foodID );
    		DietBill.put(foodID, new Integer(tempQuant));
    	}
    }
    
    public void addItem(String foodID,int num){
    	Integer foodNumber;
    	foodNumber = (Integer)DietBill.get(foodID);
    	
    	if(foodNumber == null){
    		foodNumber = new Integer(num);
    		DietBill.put(foodID, foodNumber);
    		numberFood++;
    	}else{
    		int tempQuant = foodNumber.intValue();
    		tempQuant += num;
    		DietBill.remove( foodID );
    		DietBill.put( foodID, new Integer(tempQuant) );
    	}
    }
    
    public int getnumberFood(){
    	return numberFood;
    }
    
    public int getFoodNumber(String foodID){
    	Integer foodNumber;
    	foodNumber = (Integer)DietBill.get(foodID);
    	if(foodNumber == null)
    		return 0;
    	else
    		return foodNumber.intValue();
    }
    
    public String[] getFoods()
    {
    	String []returnFoods = new String[30];
    	int curPos = 0;
    	for(Enumeration food = DietBill.keys(); food.hasMoreElements();)
    	{
    		returnFoods[curPos] = (String)food.nextElement();
    		curPos++;
    	}
    	return returnFoods;
    }
}