MappingUtils.java

package com.reucon.maven.plugin.openfire;

/*
 * 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.
 */

import org.apache.maven.artifact.Artifact;
import org.codehaus.plexus.util.StringUtils;
import org.codehaus.plexus.util.interpolation.ObjectBasedValueSource;
import org.codehaus.plexus.util.interpolation.ValueSource;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Utiities used to eveluate expression.
 * <p/>
 * TODO: this comes from the assembly plugin; refactor when it's shared.
 * <p/>
 * The expression might use any fied of the {@link Artifact} interface. Some
 * examples might be:
 * <ul>
 * <li>${artifactId}-${version}.${extension}</li>
 * <li>${artifactId}.${extension}</li>
 * </ul>
 *
 * @author Stephane Nicoll
 */
class MappingUtils
{

    /**
     * Evaluates the specified expression for the given artifact.
     *
     * @param expression the expression to evaluate
     * @param artifact   the artifact to use as value object for tokens
     * @return expression the evaluated expression
     */
    public static String evaluateFileNameMapping(String expression, Artifact artifact)

    {
        String value = expression;

        // FIXME: This is BAD! Accessors SHOULD NOT change the behavior of the object.
        artifact.isSnapshot();

        RegexBasedInterpolator interpolator = new RegexBasedInterpolator();

        interpolator.addValueSource(new ObjectBasedValueSource(artifact));
        interpolator.addValueSource(new ObjectBasedValueSource(artifact.getArtifactHandler()));

        Properties classifierMask = new Properties();
        classifierMask.setProperty("classifier", "");

        interpolator.addValueSource(new PropertiesInterpolationValueSource(classifierMask));

        value = interpolator.interpolate(value, "__artifact");

        return value;
    }


    static class PropertiesInterpolationValueSource
            implements ValueSource
    {

        private final Properties properties;

        public PropertiesInterpolationValueSource(Properties properties)
        {
            this.properties = properties;
        }

        public Object getValue(String key)
        {
            return properties.getProperty(key);
        }

    }


    /**
     * This a copy of the class in plexus-utils 1.4
     * <p/>
     * TODO: remove this once the plugin can depend on plexus-utils 1.4
     */
    static class RegexBasedInterpolator
    {

        private List valueSources;

        public RegexBasedInterpolator()
        {
            valueSources = new ArrayList();
        }

        public RegexBasedInterpolator(List valueSources)
        {
            this.valueSources = new ArrayList(valueSources);
        }

        public void addValueSource(ValueSource valueSource)
        {
            this.valueSources.add(valueSource);
        }

        public void removeValuesSource(ValueSource valueSource)
        {
            this.valueSources.remove(valueSource);
        }

        public String interpolate(String input, String thisPrefixPattern)
        {
            String result = input;

            Pattern expressionPattern = Pattern.compile("\\$\\{(" + thisPrefixPattern + ")?([^}]+)\\}");
            Matcher matcher = expressionPattern.matcher(result);

            while (matcher.find())
            {
                String wholeExpr = matcher.group(0);
                String realExpr = matcher.group(2);

                if (realExpr.startsWith("."))
                {
                    realExpr = realExpr.substring(1);
                }

                Object value = null;
                for (Iterator it = valueSources.iterator(); it.hasNext() && value == null;)
                {
                    ValueSource vs = (ValueSource) it.next();

                    value = vs.getValue(realExpr);
                }

                // if the expression refers to itself, die.
                if (wholeExpr.equals(value))
                {
                    throw new IllegalArgumentException("Expression: \'" + wholeExpr + "\' references itself.");
                }

                if (value != null)
                {
                    result = StringUtils.replace(result, wholeExpr, String.valueOf(value));
                    // could use:
                    // result = matcher.replaceFirst( stringValue );
                    // but this could result in multiple lookups of stringValue, and replaceAll is not correct behaviour
                    matcher.reset(result);
                }
            }

            return result;
        }

    }

}