IncludeProjectDependenciesComponentConfigurator.java

/*
 * Copyright 2010-2017 Boxfuse GmbH
 *
 * 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.flywaydb.maven;

import org.codehaus.classworlds.ClassRealm;
import org.codehaus.plexus.component.configurator.AbstractComponentConfigurator;
import org.codehaus.plexus.component.configurator.ComponentConfigurationException;
import org.codehaus.plexus.component.configurator.ConfigurationListener;
import org.codehaus.plexus.component.configurator.converters.composite.ObjectWithFieldsConverter;
import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluator;
import org.codehaus.plexus.configuration.PlexusConfiguration;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

/**
 * A custom ComponentConfigurator which adds the project's runtime classpath elements to the plugin's classpath.
 *
 * @plexus.component role="org.codehaus.plexus.component.configurator.ComponentConfigurator"
 * role-hint="include-project-dependencies"
 * @plexus.requirement role="org.codehaus.plexus.component.configurator.converters.lookup.ConverterLookup"
 * role-hint="default"
 */
@SuppressWarnings({"JavaDoc", "UnusedDeclaration"})
public class IncludeProjectDependenciesComponentConfigurator extends AbstractComponentConfigurator {
    public void configureComponent(Object component, PlexusConfiguration configuration,
                                   ExpressionEvaluator expressionEvaluator, ClassRealm containerRealm,
                                   ConfigurationListener listener)
            throws ComponentConfigurationException {

        addProjectDependenciesToClassRealm(expressionEvaluator, containerRealm);
        ObjectWithFieldsConverter converter = new ObjectWithFieldsConverter();
        converter.processConfiguration(converterLookup, component, containerRealm.getClassLoader(), configuration,
                expressionEvaluator, listener);
    }

    @SuppressWarnings({"unchecked"})
    private void addProjectDependenciesToClassRealm(ExpressionEvaluator expressionEvaluator, ClassRealm containerRealm) throws ComponentConfigurationException {
        List<String> classpathElements;
        try {
            classpathElements = (List<String>) expressionEvaluator.evaluate("${project.testClasspathElements}");
        } catch (ExpressionEvaluationException e) {
            throw new ComponentConfigurationException("There was a problem evaluating: ${project.testClasspathElements}", e);
        }

        // Add the project dependencies to the ClassRealm
        final URL[] urls = buildURLs(classpathElements);
        for (URL url : urls) {
            containerRealm.addConstituent(url);
        }
    }

    private URL[] buildURLs(List<String> classpathElements) throws ComponentConfigurationException {
        // Add the projects classes and dependencies
        List<URL> urls = new ArrayList<URL>(classpathElements.size());
        for (String element : classpathElements) {
            try {
                final URL url = new File(element).toURI().toURL();
                urls.add(url);
            } catch (MalformedURLException e) {
                throw new ComponentConfigurationException("Unable to access project dependency: " + element, e);
            }
        }

        // Add the plugin's dependencies (so Trove stuff works if Trove isn't on
        return urls.toArray(new URL[urls.size()]);
    }
}