validationhelper.java

我在加拿大学习的一个比较复杂的在线银行程序.

package com.ebusiness.ebank.util;

/**
 * <p>Title: </p>
 * <p>Description:  This is a helper class for deeply validating the values users entered</p>
 *
 * <p>Copyright: Copyright (c) 2005</p>
 *
 * <p>Company: eBusiness Inc., All right reserved</p>
 *
 * @author unascribed
 *
 * @version 1.0
 */

import java.util.Map;
import java.util.List;
import java.util.Collections;

public class ValidationHelper
{
    private List    countryCodes;
    private Map     stateProvCodeMap;

    private static ValidationHelper instance;

    static
    {
        instance = new ValidationHelper();
    }

    private ValidationHelper()
    {
        //initialize the Map and List
        StaticDBData dbData = StaticDBData.getInstance();
        countryCodes = dbData.getCountryCodes();
        stateProvCodeMap = dbData.getStateProvCodeMap();
    }

    public static ValidationHelper getInstance()
    {
        return instance;
    }

    //Verify if the specified state/province is a valid state/province for the specified country
    public boolean isStateProvValid(String country, String stateProv)
    {
        return Collections.binarySearch((List)stateProvCodeMap.get(country), stateProv) < 0 ? false : true;
    }

    //Verify if the specified country is a valid country
    public boolean isCountryValid(String country)
    {
        return Collections.binarySearch(countryCodes, country) < 0 ? false : true;
    }
}