org.yakindu.sct.commons.WorkspaceClassLoaderFactory.java Source code

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Here is the source code for org.yakindu.sct.commons.WorkspaceClassLoaderFactory.java

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/**
 * Copyright (c) 2011 committers of YAKINDU and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * Contributors:
 *    committers of YAKINDU - initial API and implementation
 * 
 */
package org.yakindu.sct.commons;

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

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.launching.JavaRuntime;

import com.google.common.collect.Lists;

/**
 * Factory for {@link ClassLoader}s based on {@link IProject}s inside the
 * workspace
 * 
 * @author koenemann - Initial contribution and API
 * @author holger willebrandt
 */
public class WorkspaceClassLoaderFactory {

    private final boolean resolveSimpleProjectReferences;

    public WorkspaceClassLoaderFactory() {
        this(false);
    }

    /**
     * @param resolveSimpleProjectReferences
     *            whether project references should be resolved for non-java
     *            projects
     */
    public WorkspaceClassLoaderFactory(boolean resolveSimpleProjectReferences) {
        this.resolveSimpleProjectReferences = resolveSimpleProjectReferences;
    }

    /**
     * Creates a {@link ClassLoader} that can be used to load resources from the
     * workspace.
     * 
     * @deprecated use factory method that takes a parent {@link ClassLoader}
     */
    public ClassLoader createClassLoader(IProject project) {
        return createClassLoader(project, WorkspaceClassLoaderFactory.class.getClassLoader());
    }

    /**
     * Creates a {@link ClassLoader} that can be used to load resources from the
     * workspace.
     */
    public ClassLoader createClassLoader(IProject project, ClassLoader parent) {
        final List<URL> urls = Lists.newArrayList();

        addClasspathEntries(project, urls);

        return URLClassLoader.newInstance(urls.toArray(new URL[urls.size()]), parent);
    }

    protected void addClasspathEntries(IProject project, List<URL> urls) {
        IJavaProject javaProject = toJavaProject(project);
        if (javaProject != null) {
            addJavaClasspathEntries(javaProject, urls);
        } else {
            try {
                urls.add(getFileSystemFile(project).toURI().toURL());
            } catch (MalformedURLException e1) {
                e1.printStackTrace();
            }
            if (resolveSimpleProjectReferences) {
                addReferencedProjectsClasspaths(project, urls);
            }
        }
    }

    protected void addReferencedProjectsClasspaths(IProject project, List<URL> urls) {
        try {
            IProject[] referencedProjects = project.getReferencedProjects();
            for (IProject iProject : referencedProjects) {
                addClasspathEntries(iProject, urls);
            }
        } catch (CoreException e) {
            e.printStackTrace();
        }
    }

    protected File getFileSystemFile(IResource resource) {
        return new File(resource.getWorkspace().getRoot().getRawLocation().toFile().getAbsolutePath()
                + File.separator + resource.getFullPath().toFile().getAbsolutePath());
    }

    protected IJavaProject toJavaProject(IProject project) {
        IJavaProject javaProject = JavaCore.create(project);
        if (javaProject.exists()) {
            return javaProject;
        }
        return null;
    }

    protected void addJavaClasspathEntries(IJavaProject project, List<URL> urls) {
        try {
            urls.addAll(Lists.newArrayList(convertClassPath(JavaRuntime.computeDefaultRuntimeClassPath(project))));
        } catch (CoreException e) {
            e.printStackTrace();
        }
    }

    /**
     * Converting string classpath to {@link URL}s.
     */
    private static URL[] convertClassPath(String[] classPath) {
        final URL[] urls = new URL[classPath.length];
        for (int i = 0; i < classPath.length; i++) {
            final String entry = classPath[i];
            final IPath path = new Path(entry);
            try {
                final URL url = path.toFile().toURI().toURL();
                urls[i] = url;
            } catch (MalformedURLException e) {
                throw new RuntimeException("Could not convert classpath entry to URL: " + path.toString(), e);
            }
        }
        return urls;
    }

}