/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed 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.cocoon.woody.datatype.validationruleimpl;
import org.apache.cocoon.woody.datatype.ValidationError;
import org.apache.cocoon.woody.util.I18nMessage;
import org.apache.cocoon.woody.Constants;
import org.outerj.expression.ExpressionContext;
/**
* 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 are depended on the credit card type and such validation
* is not performed by this validation rule.
*
* @version $Id: Mod10ValidationRule.java,v 1.6 2004/03/09 13:53:47 reinhard Exp $
*/
public class Mod10ValidationRule extends AbstractValidationRule {
public ValidationError validate(Object value, ExpressionContext expressionContext) {
String numberToCheck = (String)value;
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))
return hasFailMessage() ? getFailMessage() : new ValidationError(new I18nMessage("validation.mod10", Constants.I18N_CATALOGUE));
else
return null;
}
public boolean supportsType(Class clazz, boolean arrayType) {
return String.class.isAssignableFrom(clazz) && !arrayType;
}
}