trunk/bval-jsr303/src/main/java/org/apache/bval/constraints/PatternValidator.java

/*
 * 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.bval.constraints;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import javax.validation.constraints.Pattern;
import java.util.regex.PatternSyntaxException;

/**
 * validator using a regular expression,
 * based on the jsr303 Pattern constraint annotation.
 */
public class PatternValidator implements ConstraintValidator<Pattern, String> {
    protected java.util.regex.Pattern pattern;

    public void initialize(Pattern annotation) {
        Pattern.Flag flags[] = annotation.flags();
        int intFlag = 0;
        for (Pattern.Flag flag : flags) {
            intFlag = intFlag | flag.getValue();
        }

        try {
            pattern = java.util.regex.Pattern.compile(annotation.regexp(), intFlag);
        } catch (PatternSyntaxException e) {
            throw new IllegalArgumentException("Invalid regular expression.", e);
        }
    }


    public boolean isValid(String value, ConstraintValidatorContext context) {
        return value == null || pattern.matcher(value).matches();
    }
}