ReportUtils.java

/*
 * This program is free software; you can redistribute it and/or modify it under the 
 * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software 
 * Foundation.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this 
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html 
 * or from the Free Software Foundation, Inc., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; 
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * Copyright 2006 - 2009 Pentaho Corporation.  All rights reserved.
 *
*/
package org.pentaho.platform.plugin.action.jfreereport.helper;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.HashMap;
import java.util.Map;

import org.jfree.io.IOUtils;
import org.pentaho.platform.api.engine.IActionSequenceResource;
import org.pentaho.platform.api.engine.IApplicationContext;
import org.pentaho.platform.api.engine.IPentahoSession;
import org.pentaho.platform.api.repository.ISolutionRepository;
import org.pentaho.platform.engine.core.system.PentahoSystem;
import org.pentaho.platform.plugin.action.messages.Messages;

/**
 * Creation-Date: 07.07.2006, 15:49:35
 * 
 * @author Thomas Morgner
 */
public class ReportUtils {
  private static class ClassLoaderEntry implements Serializable {
    private static final long serialVersionUID = 8925334939030498948L;

    private transient ClassLoader entry;

    public ClassLoaderEntry(final ClassLoader entry) {
      this.entry = entry;
    }

    public ClassLoader getEntry() {
      return entry;
    }
  }

  private ReportUtils() {
  }

  public static synchronized File getTempDirectory(final IPentahoSession session) {
    IApplicationContext ctx = PentahoSystem.getApplicationContext();
    if (ctx != null) {
      final String fileOutputPath = ctx.getFileOutputPath("system/tmp/"); //$NON-NLS-1$
      final File tempDir = new File(fileOutputPath);
      final String id = session.getId();

      final File userTempDir;
      if (id == null) {
        // typical sloopy programming! Someone forgot to check null values.
        userTempDir = tempDir;
      } else {
        userTempDir = new File(tempDir, id);
      }

      // this operation silently fails if the dir already exists.
      userTempDir.mkdir();
      return userTempDir;
    }
    throw new IllegalStateException(Messages.getInstance().getString("ReportUtils.ERROR_0036_PENTAHO_SYSTEM_NOT_OK")); //$NON-NLS-1$
  }

  public static ClassLoader createJarLoader(final IPentahoSession session, final IActionSequenceResource resource) {

    // todo: We cant clean the temp directory ...
    // session.addListener (,..) is needed
    synchronized (session) {
      try {
        final URL url = ReportUtils.getURL(session, resource, true);
        if (url == null) {
          return null;
        }

        final Map cache = ReportUtils.getClassLoaderCache(session);
        ClassLoaderEntry entry = (ClassLoaderEntry) cache.get(url);
        if (entry != null) {
          if (entry.getEntry() != null) {
            return entry.getEntry();
          }
        }

        // now wrap the beast into a jar URL ...
        final URL jarURL = new URL("jar:" + url.toExternalForm() + "!/"); //$NON-NLS-1$ //$NON-NLS-2$
        final URLClassLoader urlClassLoader = URLClassLoader.newInstance(new URL[] { jarURL });
        cache.put(url, new ClassLoaderEntry(urlClassLoader));
        return urlClassLoader;
      } catch (IOException e) {
        // something went wrong ..
        return null;
      }
    }
  }

  private static Map getClassLoaderCache(final IPentahoSession session) {
    synchronized (session) {
      Object maybeMap = session.getAttribute("-x-pentaho-classloaders"); //$NON-NLS-1$
      if (maybeMap instanceof Map) {
        return (Map) maybeMap;
      }
      Map map = new HashMap();
      session.setAttribute("-x-pentaho-classloaders", map); //$NON-NLS-1$
      return map;
    }
  }

  private static URL getURL(final IPentahoSession session, final IActionSequenceResource resource, final boolean create)
      throws IOException {
    if (resource.getSourceType() == IActionSequenceResource.URL_RESOURCE) {
      return new URL(resource.getAddress());
    }
    if (resource.getSourceType() == IActionSequenceResource.FILE_RESOURCE) {
      File file = new File(resource.getAddress());
      if (file.exists() && file.canRead()) {
        return file.toURL();
      }
    }
    if (resource.getSourceType() == IActionSequenceResource.SOLUTION_FILE_RESOURCE) {
      String reportJarPath = PentahoSystem.getApplicationContext().getSolutionPath(resource.getAddress());
      File file = new File(reportJarPath);
      if (file.exists() && file.canRead()) {
        return file.toURL();
      }
    }

    if (create) {
      // ok, fall back to copy the file into the temp dir and to load it from
      // there...
      File temp = ReportUtils.getTempDirectory(session);
      File tempFile = PentahoSystem.getApplicationContext().createTempFile(session, "loaded-jar-", ".jar", temp, true); //$NON-NLS-1$ //$NON-NLS-2$
      // if that fails, we dont have to waste our time on copying the stuff ..
      final URL url = tempFile.toURL();

      final ISolutionRepository solutionRepository = PentahoSystem.get(ISolutionRepository.class, session);
      final InputStream in = solutionRepository.getResourceInputStream(resource, true, ISolutionRepository.ACTION_EXECUTE);
      final OutputStream out = new BufferedOutputStream(new FileOutputStream(tempFile));
      try {
        IOUtils.getInstance().copyStreams(in, out);
      } finally {
        in.close();
        out.close();
      }
      return url;
    } else {
      return null;
    }
  }

  public static URL getURL(final IPentahoSession session, final IActionSequenceResource resource) throws IOException {
    return ReportUtils.getURL(session, resource, false);
  }
}