/*
 * 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
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 *  http://www.apache.org/licenses/LICENSE-2.0
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 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Other licenses:
 * -----------------------------------------------------------------------------
 * Commercial licenses for this work are available. These replace the above
 * ASL 2.0 and offer limited warranties, support, maintenance, and commercial
 * database integrations.
 *
 * For more information, please visit: http://www.jooq.org/licenses
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package org.jooq.util.jaxb.tools;

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

import javax.xml.bind.annotation.adapters.XmlAdapter;

/**
 * An {@link XmlAdapter} that implements useful features after parsing XML
 * strings with JAXB.
 * <p>
 * Supported features are:
 * <ul>
 * <li>[#2401] String-trimming, taking out whitespace from JAXB-bound XML
 * content.</li>
 * <li>[#4550] Property expression resolution</li>
 * </ul>
 *
 * @author Lukas Eder
 */
public class StringAdapter extends XmlAdapter<String, String> {

    private static final Pattern PROPERTY_PATTERN = Pattern.compile("\\$\\{(.*?)\\}");

    @Override
    public final String unmarshal(String v) throws Exception {
        if (v == null)
            return null;

        String result = v.trim();

        Matcher matcher = PROPERTY_PATTERN.matcher(result);
        while (matcher.find())
            result = result.replace(matcher.group(0), System.getProperty(matcher.group(1), matcher.group(0)));

        return result;
    }

    @Override
    public final String marshal(String v) throws Exception {
        if (v == null)
            return null;
        return v.trim();
    }
}