fileconfigstorage.java

来自「swing编写的库存管理程序。毕业设计类」· Java 代码 · 共 167 行

/**
 * ========================================
 * JFreeReport : a free Java report library
 * ========================================
 *
 * Project Info:  http://www.jfree.org/jfreereport/index.html
 * Project Lead:  Thomas Morgner;
 *
 * (C) Copyright 2000-2003, by Simba Management Limited and Contributors.
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * ------------------------------
 * FileConfigStorage.java
 * ------------------------------
 * (C)opyright 2003, by Thomas Morgner and Contributors.
 *
 * Original Author:  Thomas Morgner;
 * Contributor(s):   David Gilbert (for Simba Management Limited);
 *
 * $Id: FileConfigStorage.java,v 1.8 2003/09/02 15:05:32 taqua Exp $
 *
 * Changes
 * -------------------------
 * 14-Jul-2003 : Initial version
 *
 */

package org.jfree.report.modules.misc.configstore.filesystem;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Properties;

import org.jfree.report.modules.misc.configstore.base.ConfigFactory;
import org.jfree.report.modules.misc.configstore.base.ConfigStorage;
import org.jfree.report.modules.misc.configstore.base.ConfigStoreException;
import org.jfree.report.util.Log;

/**
 * The FileConfigStorage is a storage provider that stores its content on
 * the local filesystem. The directory used contains the data as plain text
 * property files.
 *
 * @author Thomas Morgner
 */
public class FileConfigStorage implements ConfigStorage
{
  /** The base directory of the storage provider. */
  private final File baseDirectory;
  /** The configuration header text that is appended to all property files. */
  private static final String CONFIGHEADER =
      "part of the jfreereport filesystem config store";

  /**
   * Creates a new file config storage and stores the contents in the given
   * directory.
   *
   * @param baseDirectory the directory that should contain the files.
   */
  public FileConfigStorage(final File baseDirectory)
  {
    this.baseDirectory = baseDirectory;
  }

  /**
   * Stores the given properties on the defined path.
   * <p>
   * This implementation stores the data as property files.
   *
   * @see org.jfree.report.modules.misc.configstore.base.ConfigStorage
   * #storeProperties(java.lang.String, java.util.Properties)
   *
   * @param configPath the configuration path that specifies where to store
   * the properties.
   * @param properties the properties which should be stored.
   * @throws ConfigStoreException if an error occured.
   */
  public void storeProperties(final String configPath, final Properties properties)
      throws ConfigStoreException
  {
    if (ConfigFactory.isValidPath(configPath) == false)
    {
      throw new IllegalArgumentException("The give path is not valid.");
    }
    final File target = new File(baseDirectory, configPath);
    if (target.exists() == true && target.canWrite() == false)
    {
      Log.info ("The configuration file is not writeable. Ignoring " + target);
      return;
    }
    try
    {
      final OutputStream out = new BufferedOutputStream(new FileOutputStream(target));
      properties.store(out, CONFIGHEADER);
      out.close();
    }
    catch (Exception e)
    {
      throw new ConfigStoreException("Failed to write config " + configPath, e);
    }
  }

  /**
   * Loads the properties from the given path, specifying the given properties
   * as default.
   *
   * @param configPath the configuration path from where to load the properties.
   * @param defaults the property set that acts as fallback to provide default
   * values.
   * @return the loaded properties.
   * @throws ConfigStoreException if an error occured.
   */
  public Properties loadProperties(final String configPath, final Properties defaults)
      throws ConfigStoreException
  {
    if (ConfigFactory.isValidPath(configPath) == false)
    {
      throw new IllegalArgumentException("The give path is not valid.");
    }
    try
    {
      final Properties properties = new Properties(defaults);
      final File target = new File(baseDirectory, configPath);
      final InputStream in = new BufferedInputStream(new FileInputStream(target));
      properties.load(in);
      in.close();
      return properties;
    }
    catch (Exception e)
    {
      throw new ConfigStoreException("Failed to read config" + configPath, e);
    }
  }

  /**
   * Tests, whether some configuration data exists for the given configuration.
   * @param configPath the configuration path to the property storage.
   * @return true, if there are properties under this path, false otherwise.
   */
  public boolean existsProperties(final String configPath)
  {
    if (ConfigFactory.isValidPath(configPath) == false)
    {
      throw new IllegalArgumentException("The give path is not valid.");
    }

    final File target = new File(baseDirectory, configPath);
    return target.exists() && target.canRead();
  }
}