core-it-support/core-it-plugins/maven-it-plugin-class-loader/maven-it-plugin-class-loader/src/main/java/org/apache/maven/plugin/coreit/LoadDependenciesMojo.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.plugin.coreit;

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

import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugins.annotations.LifecyclePhase;
import org.apache.maven.plugins.annotations.Mojo;
import org.apache.maven.plugins.annotations.Parameter;
import org.apache.maven.plugins.annotations.ResolutionScope;

/**
 * Loads classes and/or resources from a custom class loader that holds the project dependencies and records the results
 * in a properties file.
 *
 * @author Benjamin Bentmann
 *
 */
@Mojo(
        name = "load-dependencies",
        defaultPhase = LifecyclePhase.INITIALIZE,
        requiresDependencyResolution = ResolutionScope.COMPILE)
public class LoadDependenciesMojo extends AbstractLoadMojo {

    /**
     * The project's class path to load classes/resources from.
     */
    @Parameter(defaultValue = "${project.compileClasspathElements}", readonly = true)
    private List classPath;

    /**
     * The path to the properties file used to track the results of the class/resource loading via the project class
     * loader.
     */
    @Parameter(property = "clsldr.projectClassLoaderOutput")
    private File projectClassLoaderOutput;

    /**
     * Runs this mojo.
     *
     * @throws MojoExecutionException If the output file could not be created.
     */
    public void execute() throws MojoExecutionException {
        URL[] urls = new URL[classPath.size()];
        for (int i = 0; i < urls.length; i++) {
            try {
                urls[i] = new File((String) classPath.get(i)).toURI().toURL();
                getLog().info("[MAVEN-CORE-IT-LOG] Using " + urls[i]);
            } catch (MalformedURLException e) {
                getLog().error("[MAVEN-CORE-IT-LOG] Failed to convert to URL " + classPath.get(i), e);
            }
        }

        ClassLoader projectClassLoader = new URLClassLoader(urls, getClass().getClassLoader());

        ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
        try {
            Thread.currentThread().setContextClassLoader(projectClassLoader);

            execute(projectClassLoaderOutput, projectClassLoader);
        } finally {
            Thread.currentThread().setContextClassLoader(contextClassLoader);
        }
    }
}