FileSystemXmlPluginProvider.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 2010 Pentaho Corporation.  All rights reserved.
 *
 * Created Jan, 2010
 * @author jdixon
 */
package org.pentaho.platform.plugin.services.pluginmgr;

import java.io.File;
import java.io.FileInputStream;
import java.io.FilenameFilter;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.apache.commons.io.IOCase;
import org.apache.commons.io.filefilter.NameFileFilter;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.pentaho.platform.api.engine.IPentahoSession;
import org.pentaho.platform.api.engine.IPlatformPlugin;
import org.pentaho.platform.api.engine.PlatformPluginRegistrationException;
import org.pentaho.platform.api.repository.ISolutionRepository;
import org.pentaho.platform.engine.core.system.PentahoSystem;
import org.pentaho.platform.plugin.services.messages.Messages;
import org.pentaho.platform.util.logging.Logger;

/**
 * A plugin provider that does not rely on an ISolutionRepository being configured
 * @author jamesdixon
 *
 */
public class FileSystemXmlPluginProvider extends SystemPathXmlPluginProvider {

  @Override
  public List<IPlatformPlugin> getPlugins(IPentahoSession session) throws PlatformPluginRegistrationException {
    List<IPlatformPlugin> plugins = new ArrayList<IPlatformPlugin>();

    // look in each of the system setting folders looking for plugin.xml files
    String systemPath = PentahoSystem.getApplicationContext().getSolutionPath("system"); //$NON-NLS-1$
    File systemDir = new File(systemPath);
    if (!systemDir.exists() || !systemDir.isDirectory()) {
      throw new PlatformPluginRegistrationException(Messages.getInstance()
          .getErrorString("PluginManager.ERROR_0004_CANNOT_FIND_SYSTEM_FOLDER")); //$NON-NLS-1$
    }
    File kids[] = systemDir.listFiles();
    // look at each child to see if it is a folder
    for (File kid : kids) {
      if (kid.isDirectory()) {
        try {
          processDirectory(plugins, kid, null, session);
        } catch (Throwable t) {
          //don't throw an exception.  we need to continue to process any remaining good plugins
          String msg = Messages.getInstance().getErrorString(
              "SystemPathXmlPluginProvider.ERROR_0001_FAILED_TO_PROCESS_PLUGIN", kid.getAbsolutePath()); //$NON-NLS-1$
          Logger.error(getClass().toString(), msg, t);
          PluginMessageLogger.add(msg);
        }
      }
    }

    return Collections.unmodifiableList(plugins);
  }
  
  @Override
  protected void processDirectory(List<IPlatformPlugin> plugins, File folder, ISolutionRepository repo,
      IPentahoSession session) throws PlatformPluginRegistrationException {
    // see if there is a plugin.xml file
    FilenameFilter filter = new NameFileFilter("plugin.xml", IOCase.SENSITIVE); //$NON-NLS-1$
    File kids[] = folder.listFiles(filter);
    if (kids == null || kids.length == 0) {
      return;
    }
    boolean hasLib = false;
    filter = new NameFileFilter("lib", IOCase.SENSITIVE); //$NON-NLS-1$
    kids = folder.listFiles(filter);
    if (kids != null && kids.length > 0) {
      hasLib = kids[0].exists() && kids[0].isDirectory();
    }
    // we have found a plugin.xml file
    // get the file from the repository
    String path = "system" + File.separatorChar + folder.getName() + File.separatorChar + "plugin.xml"; //$NON-NLS-1$ //$NON-NLS-2$
    Document doc = null;
    try {
      File f = new File( PentahoSystem.getApplicationContext().getSolutionPath( path ) );
      InputStream in = new FileInputStream( f );
      StringBuilder sb = new StringBuilder();
      byte b[] = new byte[2048];
      int n = in.read(b);
      while( n != -1 ) {
        sb.append( new String(b, 0, n) );
        n = in.read(b);
      }
      String xml = sb.toString();
      doc = DocumentHelper.parseText( xml );
      if (doc != null) {
        plugins.add(createPlugin(doc, session, folder.getName(), null, hasLib));
      }
    } catch (Exception e) {
      throw new PlatformPluginRegistrationException(Messages.getInstance().getErrorString(
          "PluginManager.ERROR_0005_CANNOT_PROCESS_PLUGIN_XML", path), e); //$NON-NLS-1$
    }
    if (doc == null) {
      throw new PlatformPluginRegistrationException(Messages.getInstance().getErrorString(
          "PluginManager.ERROR_0005_CANNOT_PROCESS_PLUGIN_XML", path)); //$NON-NLS-1$
    }
  }  
}