mdfingerprintconfig.java

来自「dump3 morpheus 0.2.9 src」· Java 代码 · 共 195 行

/**
 * DuMP3 version morpheus_0.2.9 - a duplicate/similar file finder in Java<BR>
 * Copyright 2005 Alexander Gr&auml;sser<BR>
 * All Rights Reserved, http://dump3.sourceforge.net/<BR>
 * <BR>
 * This file is part of DuMP3.<BR>
 * <BR>
 * DuMP3 is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later version.<BR>
 * <BR>
 * DuMP3 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.<BR>
 * <BR>
 * You should have received a copy of the GNU General Public License along with DuMP3; if not, write to the Free Software Foundation, Inc., 51 Franklin St,
 * Fifth Floor, Boston, MA 02110-1301 USA
 */
package net.za.grasser.duplicate.fingerprint.configure;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyVetoException;
import java.security.NoSuchAlgorithmException;
import jonelo.jacksum.JacksumAPI;
import jonelo.jacksum.algorithm.AbstractChecksum;
import net.za.grasser.duplicate.Configure;
import net.za.grasser.duplicate.fingerprint.MDFingerprint;
import org.apache.log4j.Logger;

/**
 * @author <a href="http://sourceforge.net/sendmessage.php?touser=733840">pyropunk at sourceforge dot net</a>
 * @version $Revision: 1.9 $
 */
public class MDFingerprintConfig extends FingerprintConfig {
  /**
   * <code>MSG_DIGEST</code> MDFingerprintConfig.java -
   */
  public static final String MSG_DIGEST = "messageDigest";
  /**
   * <code>serialVersionUID</code> MDFingerprintConfig.java -
   */
  private static final long serialVersionUID = 7761582108930147227L;
  /**
   * <code>log</code> MDFingerprintConfig -
   */
  private static final Logger log = Logger.getLogger(MDFingerprintConfig.class);
  /**
   * <code>fc</code> MDFingerprintConfig -
   */
  private static FingerprintConfig fc = null;
  /**
   * <code>messageDigest</code> MDFingerprint - message digest name
   */
  protected String messageDigest = "sha1";

  /**
   * This class ...
   * 
   * @author <a href="http://sourceforge.net/sendmessage.php?touser=733840">pyropunk at sourceforge dot net</a>
   * @version $Revision: 1.9 $
   */
  static class Factory extends ConfigFactory {
    /**
     * @see net.za.grasser.duplicate.fingerprint.configure.ConfigFactory#create()
     */
    @Override
    protected FingerprintConfig create() {
      return MDFingerprintConfig.getInstance();
    }
  }

  static {
    ConfigFactory.addFactory(MDFingerprintConfig.class.getSimpleName(), new Factory());
  }

  /**
   * 
   */
  private MDFingerprintConfig() {
    super();
    Configure.load();
    // get checksum algorithm from config
    try {
      setMessageDigest(Configure.getProperty("checksum", "sha1", MDFingerprint.class.getName()));
    } catch (final PropertyVetoException e) {
      log.warn("Could not set message digest.", e);
    }
  }

  /**
   * @return FingerprintConfig
   */
  public final static FingerprintConfig getInstance() {
    if (fc == null) {
      fc = new MDFingerprintConfig();
    }
    return fc;
  }

  /**
   * Sets the similarityThreshhold to the value of pSimilarityThreshhold.
   * 
   * @param pSimilarityThreshhold float - The new value.
   * @throws PropertyVetoException
   */
  @Override
  public void setSimilarityThreshhold(final float pSimilarityThreshhold) throws PropertyVetoException {
    final float oldSimilarityThreshhold = similarityThreshhold;
    // First tell the vetoers about the change.
    // If anyone objects, we don't catch the exception
    // but just let if pass on to our caller.
    vetos.fireVetoableChange(SIM_THRESH, new Float(oldSimilarityThreshhold), new Float(pSimilarityThreshhold));
    // No-one vetoed, so go ahead and make the change.
    similarityThreshhold = pSimilarityThreshhold;
    changes.firePropertyChange(SIM_THRESH, new Float(oldSimilarityThreshhold), new Float(pSimilarityThreshhold));
  }

  /**
   * @return String - Returns vcurrently selected message digest.
   */
  public final String getMessageDigest() {
    return messageDigest;
  }

  /**
   * @return String[] - Returns the list of available message digests.
   */
  public static final String[] getMessageDigests() {
    final Object[] objs = JacksumAPI.getAvailableAlgorithms().keySet().toArray();
    // have to copy - casting the whole array does not work.
    final String[] ret = new String[objs.length];
    for (int i = 0, len = objs.length; i < len; i++) {
      ret[i] = objs[i].toString();
    }
    return ret;
  }

  /**
   * @param pMd
   * @throws PropertyVetoException
   */
  public void setMessageDigest(final String pMd) throws PropertyVetoException {
    final String oldMD = messageDigest;
    vetos.fireVetoableChange(MSG_DIGEST, oldMD, pMd);
    messageDigest = pMd;
    changes.firePropertyChange(MSG_DIGEST, oldMD, pMd);
  }

  /**
   * checks whether the selected MD is a valid checksum algorithm
   * 
   * @param newValue
   * @return AbstractChecksum
   * @throws NoSuchAlgorithmException
   */
  private AbstractChecksum checkChecksum(final String newValue) throws NoSuchAlgorithmException {
    final AbstractChecksum checksum = JacksumAPI.getChecksumInstance(newValue);
    return checksum;
  }

  /**
   * @see java.beans.VetoableChangeListener#vetoableChange(java.beans.PropertyChangeEvent)
   */
  @Override
  public void vetoableChange(final PropertyChangeEvent evt) throws PropertyVetoException {
    if (evt.getPropertyName().equals(SIM_THRESH)) {
      if (((Float)evt.getNewValue()).floatValue() != 100.0) {
        throw new PropertyVetoException(evt.getPropertyName() + " must be equal to 100.0%.", evt);
      }
    } else if (evt.getPropertyName().equals(MSG_DIGEST)) {
      try {
        checkChecksum((String)evt.getNewValue());
      } catch (final NoSuchAlgorithmException ex) {
        throw new PropertyVetoException(evt.getPropertyName() + " must be a valid message digest.", evt);
      }
    }
  }

  /**
   * @see net.za.grasser.duplicate.fingerprint.configure.FingerprintConfig#getFingerprintDescription()
   */
  @Override
  public String getFingerprintDescription() {
    return "The fingerprint consists of a Message Digest (i.e. MD5, SHA1 (default), RIPEMD) hash. The message digest checksum algorithm is configurable."
        + " Choosing a simple message digest like CRC16 however, is not recommended."
        + " This fingerprint is created for all files and all files are first compared by length and MD fingerprint.";
  }

  /**
   * @see net.za.grasser.duplicate.fingerprint.configure.FingerprintConfig#getFingerprintName()
   */
  @Override
  public String getFingerprintName() {
    return "Message Digest Fingerprint";
  }
}