DashboardCopier.java

/*******************************************************************************
 * Copyright (c) 2012 Pivotal Software, Inc.
 * 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:
 *     Pivotal Software, Inc. - initial API and implementation
 *******************************************************************************/
package org.springsource.ide.eclipse.commons.gettingstarted.dashboard;

import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.io.FileUtils;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.SubProgressMonitor;
import org.springsource.ide.eclipse.commons.core.preferences.StsProperties;
import org.springsource.ide.eclipse.commons.core.templates.TemplateProcessor;
import org.springsource.ide.eclipse.commons.gettingstarted.GettingStartedActivator;

/**
 * Makes a copy of some content from one directory to another. The target
 * directory is wiped before copying, but only one copy is made per STS session.
 * Subsequent copies requested will reuse the first copy (until STS is
 * restarted).
 * 
 * @author Kris De Volder
 */
public class DashboardCopier {

	private static DashboardCopier instance = null;

	/**
	 * Cache of processed content. This cache only retains content per Eclipse
	 * session. So restarting STS should begin with a clear cache.
	 */
	private Map<String, File> copied = new HashMap<String, File>();

	private File workdir;

	private DashboardCopier() {
		workdir = new File(GettingStartedActivator.getDefault().getStateLocation().toFile(), "dashboard");
		FileUtils.deleteQuietly(workdir);
	}

	public static synchronized DashboardCopier getInstance() {
		if (instance == null) {
			instance = new DashboardCopier();
		}
		return instance;
	}

	/**
	 * Copy directory contens from some source directory to some working
	 * directory
	 */
	public static File getCopy(File from, IProgressMonitor mon) throws IOException {
		return getInstance()._getCopy(from, mon);
	}

	private File _getCopy(File from, IProgressMonitor mon) throws IOException {
		String key = from.getCanonicalPath();
		File cached = copied.get(key);
		if (cached != null && cached.exists()) {
			return cached;
		}
		File to = new File(workdir, generateFileName());
		if (!to.mkdirs()) {
			throw new IOException("Couldn't create dir " + to);
		}
		mon.beginTask("Instantiating Dashboard Content", 3);
		try {
			StsProperties props = StsProperties.getInstance(new SubProgressMonitor(mon, 1));
			Map<String, String> replacementContext = new HashMap<String, String>();
			for (String propName : props.getExplicitProperties()) {
				String value = props.get(propName);
				if (value != null) {
					replacementContext.put("${" + propName + "}", value);
				}
			}
			TemplateProcessor processor = new TemplateProcessor(replacementContext);
			processor.process(from, to);
			copied.put(key, to);
			return to;
		}
		finally {
			mon.done();
		}
	}

	long count = System.currentTimeMillis();

	private String generateFileName() {
		return "" + (count++);
	}

}