/*
 * Copyright 2005 the original author or authors.
 * 
 * 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.wamblee.crawler.impl;

import java.util.regex.Pattern;

/**
 * Configuration item for obtaining an object in case a pattern matches.
 */
class ConfigItem<ValueType> {

    private Pattern _pattern;

    private ValueType _value;

    /**
     * Constructs the item. 
     * @param aPattern Pattern. 
     * @param aValue Value. 
     */
    protected ConfigItem(String aPattern, ValueType aValue) {
        _pattern = Pattern.compile(aPattern);
        _value = aValue;
    }

    /**
     * Returns the object in case the value matches. 
     * @param aValue Value to match. 
     * @return Object in case there is a match, null otherwise. 
     */
    protected ValueType match(String aValue) {
        if (!_pattern.matcher(aValue).matches()) {
            return null;
        }
        return _value;
    }

}