org.ebayopensource.turmeric.plugins.maven.util.ProjectClassLoader.java Source code

Introduction

Here is the source code for org.ebayopensource.turmeric.plugins.maven.util.ProjectClassLoader.java

Source

/*******************************************************************************
 * Copyright (c) 2006-2010 eBay Inc. All Rights Reserved.
 * 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
 *******************************************************************************/
package org.ebayopensource.turmeric.plugins.maven.util;

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

import org.apache.maven.artifact.Artifact;
import org.apache.maven.model.Resource;
import org.apache.maven.project.MavenProject;
import org.codehaus.plexus.util.StringUtils;
import org.ebayopensource.turmeric.plugins.maven.AbstractTurmericMojo;

/**
 * Simple ClassLoader to use when testing Mojo's that need information from the project.
 * <p>
 * Such as the classpath information suitable for compiling classes, that some of the codegen utilities require.
 */
public class ProjectClassLoader extends URLClassLoader {

    public static ProjectClassLoader create(AbstractTurmericMojo mojo, ClassLoader parent)
            throws MalformedURLException {
        MavenProject project = mojo.getProject();
        URL urls[] = getMavenProjectClassLoaderURLS(project);
        return new ProjectClassLoader(urls, parent, project);
    }

    private static URL[] getMavenProjectClassLoaderURLS(MavenProject project) throws MalformedURLException {
        List<File> searchPaths = new ArrayList<File>();

        // Project Compile Artifacts
        @SuppressWarnings("unchecked")
        final List<Artifact> arts = project.getCompileArtifacts();
        if (arts != null) {
            for (Artifact arti : arts) {
                File artiFile = arti.getFile();
                if ((artiFile != null) && (artiFile.exists())) {
                    searchPaths.add(artiFile);
                }
            }
        }

        // Project Resources
        @SuppressWarnings("unchecked")
        final List<Resource> resources = project.getBuild().getResources();

        for (Resource resource : resources) {
            String resDir = resource.getDirectory();
            File dir = new File(resDir);
            if (!dir.isAbsolute()) {
                dir = new File(project.getBasedir(), resDir);
            }
            searchPaths.add(dir);
        }

        // The Classes Dir
        File classesDir = new File(project.getBuild().getOutputDirectory());
        if (!classesDir.isAbsolute()) {
            classesDir = new File(project.getBasedir(), project.getBuild().getOutputDirectory());
        }

        searchPaths.add(classesDir);

        // Compile Source Roots - (needed for codegen javac)
        @SuppressWarnings("unchecked")
        List<String> sourceRoots = project.getCompileSourceRoots();
        if (sourceRoots != null) {
            for (String srcRoot : sourceRoots) {
                if (StringUtils.isBlank(srcRoot)) {
                    // skip
                    continue;
                }
                File src = new File(srcRoot);
                if (src.exists()) {
                    searchPaths.add(new File(srcRoot));
                }
            }
        }

        int count = searchPaths.size();
        URL urls[] = new URL[count];
        for (int i = 0; i < count; i++) {
            urls[i] = searchPaths.get(i).toURI().toURL();
            System.out.printf("### ProjectClassLoader[%d]: %s%n", i, urls[i].toExternalForm());
        }

        return urls;
    }

    private MavenProject project;

    public ProjectClassLoader(URL[] urls, ClassLoader parent, MavenProject project) {
        super(urls, parent);
        this.project = project;
    }

    @Override
    public Class<?> loadClass(String name) throws ClassNotFoundException {
        // System.out.println("### " + name);
        if ("com.sun.tools.javac.Main".equals(name)) {
            System.out.println("### JavaC being loaded. updating ProjectClassLoader urls.");
            /* The codegen is attempting to compile some stuff.
             * 
             * Time to reload the search Paths (because we might have 
             * some more paths showing up as a result of being attached
             * to the build)
             */
            try {
                URL urls[] = getMavenProjectClassLoaderURLS(project);
                // Now, since we can't super.setUrls(urls), we have to add
                // what's missing instead.

                URL orig[] = getURLs();
                for (URL url : urls) {
                    if (!contains(orig, url)) {
                        System.out.println("### Adding New URL: " + url);
                        super.addURL(url);
                    }
                }

            } catch (MalformedURLException e) {
                e.printStackTrace(System.out);
            }
        }
        return super.loadClass(name);
    }

    private boolean contains(URL[] urls, URL testUrl) {
        for (URL url : urls) {
            if (url.equals(testUrl)) {
                return true;
            }
        }
        return false;
    }
}