maven-core/src/main/java/org/apache/maven/configuration/internal/DefaultBeanConfigurator.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.maven.configuration.internal;

import javax.inject.Named;
import javax.inject.Singleton;

import java.io.File;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;

import org.apache.maven.api.xml.XmlNode;
import org.apache.maven.configuration.BeanConfigurationException;
import org.apache.maven.configuration.BeanConfigurationPathTranslator;
import org.apache.maven.configuration.BeanConfigurationRequest;
import org.apache.maven.configuration.BeanConfigurationValuePreprocessor;
import org.apache.maven.configuration.BeanConfigurator;
import org.apache.maven.internal.xml.XmlNodeImpl;
import org.codehaus.plexus.component.configurator.ComponentConfigurationException;
import org.codehaus.plexus.component.configurator.ConfigurationListener;
import org.codehaus.plexus.component.configurator.converters.AbstractConfigurationConverter;
import org.codehaus.plexus.component.configurator.converters.basic.AbstractBasicConverter;
import org.codehaus.plexus.component.configurator.converters.composite.ObjectWithFieldsConverter;
import org.codehaus.plexus.component.configurator.converters.lookup.ConverterLookup;
import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluator;
import org.codehaus.plexus.component.configurator.expression.TypeAwareExpressionEvaluator;
import org.codehaus.plexus.configuration.PlexusConfiguration;
import org.codehaus.plexus.configuration.xml.XmlPlexusConfiguration;
import org.codehaus.plexus.util.xml.Xpp3Dom;

/**
 * <strong>Warning:</strong> This is an internal class that is only public for technical reasons, it is not part of the
 * public API. In particular, this class can be changed or deleted without prior notice.
 *
 */
@Named
@Singleton
public class DefaultBeanConfigurator implements BeanConfigurator {

    private final ConverterLookup converterLookup;

    public DefaultBeanConfigurator() {
        converterLookup = new EnhancedConverterLookup();
    }

    public void configureBean(BeanConfigurationRequest request) throws BeanConfigurationException {
        Objects.requireNonNull(request, "request cannot be null");
        Objects.requireNonNull(request.getBean(), "request.bean cannot be null");

        Object configuration = request.getConfiguration();
        if (configuration == null) {
            return;
        }

        PlexusConfiguration plexusConfig;
        if (configuration instanceof PlexusConfiguration) {
            plexusConfig = (PlexusConfiguration) configuration;
        } else if (configuration instanceof Xpp3Dom) {
            plexusConfig = new XmlPlexusConfiguration((Xpp3Dom) configuration);
        } else {
            throw new BeanConfigurationException("unsupported bean configuration source ("
                    + configuration.getClass().getName() + ")");
        }

        if (request.getConfigurationElement() != null) {
            plexusConfig = plexusConfig.getChild(request.getConfigurationElement());
        }

        ClassLoader classLoader = request.getClassLoader();
        if (classLoader == null) {
            classLoader = request.getBean().getClass().getClassLoader();
        }

        BeanExpressionEvaluator evaluator = new BeanExpressionEvaluator(request);

        ObjectWithFieldsConverter converter = new EnhancedConfigurationConverter();

        try {
            converter.processConfiguration(
                    converterLookup, request.getBean(), classLoader, plexusConfig, evaluator, null);
        } catch (ComponentConfigurationException e) {
            throw new BeanConfigurationException(e.getMessage(), e);
        }
    }

    static class BeanExpressionEvaluator implements TypeAwareExpressionEvaluator {

        private final BeanConfigurationValuePreprocessor preprocessor;

        private final BeanConfigurationPathTranslator translator;

        BeanExpressionEvaluator(BeanConfigurationRequest request) {
            preprocessor = request.getValuePreprocessor();
            translator = request.getPathTranslator();
        }

        public Object evaluate(String expression, Class<?> type) throws ExpressionEvaluationException {
            if (preprocessor != null) {
                try {
                    return preprocessor.preprocessValue(expression, type);
                } catch (BeanConfigurationException e) {
                    throw new ExpressionEvaluationException(e.getMessage(), e);
                }
            }
            return expression;
        }

        public Object evaluate(String expression) throws ExpressionEvaluationException {
            return evaluate(expression, null);
        }

        public File alignToBaseDirectory(File file) {
            if (translator != null) {
                return translator.translatePath(file);
            }
            return file;
        }
    }

    static class XmlConverter extends AbstractConfigurationConverter {
        @Override
        public boolean canConvert(Class<?> type) {
            return XmlNode.class.equals(type);
        }

        @Override
        public Object fromConfiguration(
                final ConverterLookup lookup,
                final PlexusConfiguration configuration,
                final Class<?> type,
                final Class<?> enclosingType,
                final ClassLoader loader,
                final ExpressionEvaluator evaluator,
                final ConfigurationListener listener)
                throws ComponentConfigurationException {

            try {
                return toXml(configuration, evaluator);
            } catch (ExpressionEvaluationException e) {
                throw new ComponentConfigurationException("Unable to convert configuration to xml node", e);
            }
        }

        XmlNode toXml(PlexusConfiguration config, ExpressionEvaluator evaluator) throws ExpressionEvaluationException {
            List<XmlNode> children = new ArrayList<>();
            for (PlexusConfiguration c : config.getChildren()) {
                children.add(toXml(c, evaluator));
            }
            String name = config.getName();
            Object value = evaluator.evaluate(config.getValue());
            return new XmlNodeImpl(name, value != null ? value.toString() : null, null, children, null);
        }
    }

    static class PathConverter extends AbstractBasicConverter {
        @Override
        public boolean canConvert(Class<?> type) {
            return Path.class.equals(type);
        }

        @Override
        protected Object fromString(String value) throws ComponentConfigurationException {
            return Paths.get(value.replace('/' == File.separatorChar ? '\\' : '/', File.separatorChar));
        }

        @Override
        public Object fromConfiguration(
                final ConverterLookup lookup,
                final PlexusConfiguration configuration,
                final Class<?> type,
                final Class<?> enclosingType,
                final ClassLoader loader,
                final ExpressionEvaluator evaluator,
                final ConfigurationListener listener)
                throws ComponentConfigurationException {
            final Object result =
                    super.fromConfiguration(lookup, configuration, type, enclosingType, loader, evaluator, listener);

            return result instanceof Path
                    ? evaluator.alignToBaseDirectory(((Path) result).toFile()).toPath()
                    : result;
        }
    }
}