SystemSettings.java

/*
 * This program is free software; you can redistribute it and/or modify it under the 
 * terms of the GNU General Public License, version 2 as published by the Free Software 
 * Foundation.
 *
 * You should have received a copy of the GNU General Public License along with this 
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/gpl-2.0.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 General Public License for more details.
 *
 *
 * Copyright 2005 - 2008 Pentaho Corporation.  All rights reserved. 
 * 
 * @created Jul 19, 2005 
 * @author Marc Batchelor
 * 
 */

package org.pentaho.platform.engine.core.system;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Node;
import org.pentaho.platform.api.engine.ISystemSettings;
import org.pentaho.platform.engine.core.messages.Messages;
import org.pentaho.platform.util.xml.dom4j.XmlDom4JHelper;

/**
 * Provides system settings data for system configuration files located in
 * the system folder of the repository. System settings for </code>PentahoSystem</code>
 * are hardcoded to exist in <repository>/system/pentaho.xml. Provides a settings
 * cache so that settings are read from the file once, and the associated DOM
 * document is cached in memory for future lookups.
 * 
 * @author unknown
 *
 */
public class SystemSettings extends PentahoBase implements ISystemSettings {
  /**
   * 
   */
  private static final long serialVersionUID = 3727605230748352557L;

  /**
   * This constant is for the overall system settings file name.
   */
  public static final String PENTAHOSETTINGSFILENAME = "pentaho.xml"; //$NON-NLS-1$

  private static final String LOG_NAME = Messages.getInstance().getString("SYSTEMSETTINGS.CODE_LOG_NAME"); //$NON-NLS-1$

  private static final Log logger = LogFactory.getLog(SystemSettings.class);

  private final Map settingsDocumentMap = Collections.synchronizedMap(new HashMap());

  String logId;

  public SystemSettings() {
    // TODO apply session-base security to the system settings
    logId = SystemSettings.LOG_NAME + ":"; //$NON-NLS-1$
    // TODO sbarkdull clean up
    //      Document doc = getSystemSettingsDocument(DEFAULT_PENTAHOSETTINGSFILENAME);
    //      if (doc == null) {
    //        throw new IllegalArgumentException(Messages.getInstance().getErrorString("SYSTEMSETTINGS.ERROR_0003_INVALID_OR_MISSING_FILE")); //$NON-NLS-1$
    //      }
  }

  public String getSystemSetting(final String path, final String settingName, final String defaultValue) {
    debug(Messages.getInstance().getString("SYSTEMSETTINGS.DEBUG_GET_SYSTEM_SETTING_PATH", File.separator + path)); //$NON-NLS-1$
    Document doc = getSystemSettingsDocument(path);
    if (doc == null) {
      return null;
    }
    Node node = doc.selectSingleNode("//" + settingName); //$NON-NLS-1$
    if (node == null) {
      return defaultValue;
    }
    return node.getText();
  }

  public String getSystemSetting(final String settingName, final String defaultValue) {
    return getSystemSetting(SystemSettings.PENTAHOSETTINGSFILENAME, settingName, defaultValue);
  }

  public List getSystemSettings(final String path, final String settingName) {
    List settings = (List)settingsDocumentMap.get(path + settingName);
    if (settings != null) {
      return settings;
    }
    Document doc = getSystemSettingsDocument(path);
    if (doc == null) {
      return null;
    }
    settings = doc.selectNodes("//" + settingName); //$NON-NLS-1$
    settingsDocumentMap.put(path + settingName, settings);
    return settings;
  }

  public List getSystemSettings(final String settingName) {
    return getSystemSettings(SystemSettings.PENTAHOSETTINGSFILENAME, settingName);
  }

  public Document getSettingsDocumentFromFile(File f) throws IOException, DocumentException {
    return XmlDom4JHelper.getDocFromFile(f, null);
  }
  
  /**
   * Get the DOM document initialized by the file specified in the <code>actionPath</code>
   * parameter. If this is the first time the document associated with <code>actionPath</code>
   * has been requested, cache the DOM document. If this is not the first time the document
   * has been requested, return the document from the cache.
   */
  public Document getSystemSettingsDocument(final String actionPath) {
    // S logId =
    // runtimeContext.getInstanceId()+":"+LOG_NAME+":"+runtimeContext.getActionName(); //$NON-NLS-1$ //$NON-NLS-2$
    Document systemSettingsDocument = (Document) settingsDocumentMap.get(actionPath);
    if (systemSettingsDocument == null) {
      File f = getFile(actionPath);
      if (f == null) {
        return null;
      }
      try {
        systemSettingsDocument = getSettingsDocumentFromFile(f);
        settingsDocumentMap.put(actionPath, systemSettingsDocument);
      } catch (DocumentException e) {
        // todo log this
        e.printStackTrace();
      } catch (IOException e) {
        // todo log this
        e.printStackTrace();
      }
    }
    return systemSettingsDocument;
  }

  /**
   * Get a <code>File</code> object that references a file in the system folder of
   * the repository. The <code>path</code> parameter is relative to the
   * system folder in the repository.
   * @param path String containing the path of a file relative to the system folder in the
   * repository
   * @return File referencing the file specified by <code>path</code> relative to repository's
   * system folder.
   */
  private File getFile(final String path) {
    File f = new File(getAbsolutePath(path));

    if (!f.exists()) {
      error(Messages.getInstance().getErrorString("SYSTEMSETTINGS.ERROR_0002_FILE_NOT_IN_SOLUTION", f.getAbsolutePath())); //$NON-NLS-1$
      return null;
    }
    debug(Messages.getInstance().getString("SYSTEMSETTINGS.DEBUG_SYSTEM_SETTINGS_GET_FILE", f.getAbsolutePath())); //$NON-NLS-1$

    return f;
  }

  /**
   * Create a String containing the complete path to the system folder in the repository,
   * and append the parameter <code>path</code> to it.
   * @param path String containing the path of a file relative to the system folder in the
   * repository
   * @return String containing the path
   */
  protected String getAbsolutePath(final String path) {
    return PentahoSystem.getApplicationContext().getSolutionPath("system" + File.separator + path); //$NON-NLS-1$
  }

  @Override
  public Log getLogger() {
    return SystemSettings.logger;
  }

  public void resetSettingsCache() {
    settingsDocumentMap.clear();
  }

  //TODO sbarkdull, this props could be cached in a map similar to how the xml docs are cached
  public Properties getSystemSettingsProperties(final String path) {
    String fullPath = PentahoSystem.getApplicationContext().getSolutionPath("system" + File.separator + path); //$NON-NLS-1$
    File propsFile = new File(fullPath);
    if (!propsFile.exists()) {
      return null;
    }
    try {
      Properties props = new Properties();
      InputStream fileInputStream = new BufferedInputStream(new FileInputStream(propsFile));
      try {
        props.load(fileInputStream);
        return props;
      } finally {
        fileInputStream.close();
      }
    } catch (FileNotFoundException e) {
      SystemSettings.logger.error(Messages.getInstance().getErrorString("SystemSettings.ERROR_0003_FAILED_INITIALIZE", path), e); //$NON-NLS-1$
    } catch (IOException ioe) {
      SystemSettings.logger.error(Messages.getInstance().getErrorString("SystemSettings.ERROR_0003_FAILED_INITIALIZE", path), ioe); //$NON-NLS-1$
    }
    return null;
  }

  public String getSystemCfgSourceName() {
    return getAbsolutePath(SystemSettings.PENTAHOSETTINGSFILENAME);
  }
}