GroupsTransform.java

/*
 * ====================
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2008-2009 Sun Microsystems, Inc. All rights reserved.
 *
 * The contents of this file are subject to the terms of the Common Development
 * and Distribution License("CDDL") (the "License").  You may not use this file
 * except in compliance with the License.
 *
 * You can obtain a copy of the License at
 * http://opensource.org/licenses/cddl1.php
 * See the License for the specific language governing permissions and limitations
 * under the License.
 *
 * When distributing the Covered Code, include this CDDL Header Notice in each file
 * and include the License file at http://opensource.org/licenses/cddl1.php.
 * If applicable, add the following below this CDDL Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
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 * ====================
 */
package org.identityconnectors.patternparser;

import java.util.LinkedList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.w3c.dom.Element;

/**
 * A GroupsTransform specifies a pattern to be used to break up the stringified
 * value into a List.
 * <p>
 * Each element of the list corresponds to a group from the pattern.
 * <p>
 * Represented in XML by
 *
 * <pre>
 * <GroupsTransform mapPattern='<b>pattern</b>'/>
 * </pre>
 */

public class GroupsTransform extends Transform<Object> {
    private static final String MAP_PATTERN = "mapPattern";
    private Pattern mapPattern;

    protected String getAttributes() {
        return super.getAttributes() + attributeToString(MAP_PATTERN, mapPattern.pattern());
    }

    /**
     * Create a GroupsTransform from an Element.
     *
     * @param element
     */
    public GroupsTransform(Element element) {
        this(element.getAttribute(MAP_PATTERN));
    }

    /**
     * Create a GroupsTransform, given a <b>mapPattern</b>.
     *
     * @param mapPattern
     *            the pattern to be used to split the input
     */
    public GroupsTransform(String mapPattern) {
        this.mapPattern = Pattern.compile(mapPattern);
    }

    /**
     * Convert <b>input</b> into a String, and apply the <b>mapPattern</b>,
     * returning all groups in the pattern as a List<String>.
     *
     * @param input
     *            the object to be transformed
     * @return a List<String> containing all the groups recognized in the
     *         <b>mapPattern</b>
     */
    @Override
    public Object transform(Object input) throws Exception {
        Matcher matcher = mapPattern.matcher(input.toString());
        if (matcher.matches()) {
            List<Object> output = new LinkedList<Object>();
            for (int i = 1; i <= matcher.groupCount(); i++) {
                output.add(matcher.group(i));
            }
            return output;
        } else {
            return input;
        }
    }
}