creditcardvalidator.java

来自「Wicket一个开发Java Web应用程序框架。它使得开发web应用程序变得容」· Java 代码 · 共 65 行

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.wicket.validation.validator;

import org.apache.wicket.validation.IValidatable;

/**
 * Performs the so-called "mod 10" algorithm to check the validity of credit card numbers such as
 * VISA.
 * <p>
 * In addition to this, the credit card number can be further validated by its length and prefix,
 * but those properties depend upon the credit card type, and such validation is not performed by
 * this validator.
 * 
 * @author Johan Compagner
 * @since 1.2.6
 */
public class CreditCardValidator extends AbstractValidator
{
	private static final long serialVersionUID = 1L;

	/**
	 * @see AbstractValidator#onValidate(IValidatable)
	 */
	protected void onValidate(IValidatable validatable)
	{
		String input = ((String)validatable.getValue());
		String numberToCheck = input.replaceAll("[ -]", "");
		int nulOffset = '0';
		int sum = 0;
		for (int i = 1; i <= numberToCheck.length(); i++)
		{
			int currentDigit = numberToCheck.charAt(numberToCheck.length() - i) - nulOffset;
			if ((i % 2) == 0)
			{
				currentDigit *= 2;
				currentDigit = currentDigit > 9 ? currentDigit - 9 : currentDigit;
				sum += currentDigit;
			}
			else
			{
				sum += currentDigit;
			}
		}
		if (!((sum % 10) == 0))
		{
			error(validatable);
		}
	}
}