code: /**
   * Copyright (c) 2004-2005, Regents of the University of California
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * Redistributions of source code must retain the above copyright notice,
   * this list of conditions and the following disclaimer.
   *
   * Redistributions in binary form must reproduce the above copyright
   * notice, this list of conditions and the following disclaimer in the
   * documentation and/or other materials provided with the distribution.
   *
   * Neither the name of the University of California, Los Angeles nor the
   * names of its contributors may be used to endorse or promote products
   * derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package cck.util;
  
  import java.util.HashMap;
  
  /**
   * The <code>Version</code> class represents a version number, including the major version, the commit number,
   * as well as the date and time of the last commit.
   *
   * @author Ben L. Titzer
   */
  public class VersionTag {
  
      private static final HashMap<String, VersionTag> tags = new HashMap<String, VersionTag>();
  
      /**
       * The <code>getVersionTag()</code> method gets the version tag for the specified module.
       *
       * @param module the name of the module as a string
       * @return a reference to the version tag for the specified module if it exists; null otherwise
       */
      public static VersionTag getVersionTag(String module) {
          return (VersionTag) tags.get(module);
      }
  
      /**
       * The <code>module</code> field stores the name of the module as a string.
       */
      public final String module;
  
      /**
       * The <code>prefix</code> field stores the string that the prefix of the version (if any) for this
       * version.
       */
      public final String prefix;
  
      /**
       * The <code>major</code> field stores the integer that represents the major number.
       */
      public final int major;
  
      /**
       * The <code>minor</code> field stores the integer that represents the minor number.
       */
      public final int minor;
  
      /**
       * The <code>commit</code> field stores the commit number (i.e. the number of code revisions committed to
       * CVS since the last release).
       */
      public final int commit;
  
      /**
       * The <code>string</code> field stores a reference to this version instance represented as a string.
       */
      public final String string;
  
      /**
       * The <code>suffix</code> field stores a reference to this version instance represented as a string
       * that is suitable as a file suffix.
       */
      public final String suffix;
  
      /**
       * The constructor for the <code>Version</code> class creates a new version object that represents
       * the version of the code.
       *
       * @param mod the module name
       * @param prefix a string representing the release name, such as <code>"Beta"</code> for example
       * @param maj    the major version number
       * @param min    the minor version number
       * @param comm   the commit number
       */
      public VersionTag(String mod, String prefix, int maj, int min, int comm) {
          this.module = mod;
          this.prefix = prefix;
          this.major = maj;
          this.minor = min;
          this.commit = comm;
          this.string = prefixString(false, ' ') + major + '.' + minor + '.' + commitNumber();
          this.suffix = prefixString(true, '-') + major + '.' + minor + '.' + commitNumber();
          tags.put(mod, this);
      }
  
      /**
       * The <code>toString()</code> method converts this version to a string.
       *
       * @return a string representation of this version
       */
      public String toString() {
          return string;
      }
  
      private String prefixString(boolean lower, char suffix) {
          if ( prefix.length() == 0 ) return "";
          return (lower ? prefix.toLowerCase() : prefix) + suffix;
      }
  
      private String commitNumber() {
          if ( commit < 10 ) return "00"+commit;
          if ( commit < 100 ) return "0"+commit;
          return Integer.toString(commit);
      }
  
      /**
       * The <code>isStable()</code> method returns whether this version tag corresponds to
       * a stable release of the source code. It determines this by the <code>minor</code>
       * version number; if this number is even, then the code is considered to be stable.
       *
       * @return true if this version tag corresponds to a stable version
       */
      public boolean isStable() {
          return minor % 2 == 0;
      }
  }
  