001    /* ActivationDesc.java -- record with info to activate an object
002       Copyright (c) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    package java.rmi.activation;
039    
040    import java.io.Serializable;
041    import java.rmi.MarshalledObject;
042    
043    /**
044     * Contains the information, necessary to activate the object. This information
045     * includes:
046     * <ul>
047     * <li>the object class name</li>
048     * <li>the object group identifier</li>
049     * <li>the code location (codebase URL) that can be used to load the class
050     * remotely</li>
051     * <li>the object restart mode</li>
052     * <li>the object specific intialization information</li>
053     * </ul>
054     *
055     * @author Audrius Meskauskas (audriusa@bioinformatics.org) (from stub)
056     */
057    public final class ActivationDesc
058        implements Serializable
059    {
060      /**
061       * Use SVUID for interoperability.
062       */
063      static final long serialVersionUID = 7455834104417690957L;
064    
065      /**
066       * The group id.
067       */
068      private ActivationGroupID groupid;
069    
070      /**
071       * The class name.
072       */
073      private String classname;
074    
075      /**
076       * The code location URL.
077       */
078      private String location;
079    
080      /**
081       * The object specific intitalization data.
082       */
083      private MarshalledObject<?> data;
084    
085      /**
086       * The start mode.
087       */
088      private boolean restart;
089    
090      /**
091       * Create the new activation description, assuming the object group is the
092       * {@link ActivationGroup#currentGroupID()}.
093       *
094       * @param className the object fully qualified class name
095       * @param location the code base URL
096       * @param data the object initialization data, contained in a marshalled form
097       */
098      public ActivationDesc(String className, String location, MarshalledObject<?> data)
099          throws ActivationException
100      {
101        this(ActivationGroup.currentGroupID(), className, location, data, false);
102      }
103    
104      /**
105       * Create the new activation description, assuming the object group is the
106       * {@link ActivationGroup#currentGroupID()}.
107       *
108       * @param className the object fully qualified class name
109       * @param location the code base URL
110       * @param data the object initialization data, contained in a marshalled form
111       * @param restart specifies reactivation mode after crash. If true, the object
112       *          is activated when activator is restarted or the activation group
113       *          is restarted. If false, the object is only activated on demand.
114       *          This flag does has no effect during the normal operation (the
115       *          object is normally activated on demand).
116       */
117      public ActivationDesc(String className, String location,
118                            MarshalledObject<?> data, boolean restart)
119          throws ActivationException
120      {
121        this(ActivationGroup.currentGroupID(), className, location, data, restart);
122      }
123    
124      /**
125       * Create the new activation description. Under crash, the object will only
126       * be reactivated on demand.
127       *
128       * @param groupID the object group id.
129       * @param className the object fully qualified class name
130       * @param location the code base URL
131       * @param data the object initialization data, contained in a marshalled form
132       */
133      public ActivationDesc(ActivationGroupID groupID, String className,
134                            String location, MarshalledObject<?> data)
135      {
136        this(groupID, className, location, data, false);
137      }
138    
139      /**
140       * Create the new activation description, providing full information.
141       *
142       * @param groupID the object group id.
143       * @param className the object fully qualified class name
144       * @param location the code base URL
145       * @param data the object initialization data, contained in a marshalled form
146       * @param restart specifies reactivation mode after crash. If true, the object
147       *          is activated when activator is restarted or the activation group
148       *          is restarted. If false, the object is only activated on demand.
149       *          This flag does has no effect during the normal operation (the
150       *          object is normally activated on demand).
151       */
152      public ActivationDesc(ActivationGroupID groupID, String className,
153                            String location, MarshalledObject<?> data, boolean restart)
154      {
155        this.groupid = groupID;
156        this.classname = className;
157        this.location = location;
158        this.data = data;
159        this.restart = restart;
160      }
161    
162      public ActivationGroupID getGroupID()
163      {
164        return groupid;
165      }
166    
167      /**
168       * Get the class name of the object being activated
169       *
170       * @return the fully qualified class name of the object being activated
171       */
172      public String getClassName()
173      {
174        return classname;
175      }
176    
177      /**
178       * Get the code location URL ("codebase") of the object being activated.
179       *
180       * @return the codebase of the object being activated.
181       */
182      public String getLocation()
183      {
184        return location;
185      }
186    
187      public MarshalledObject<?> getData()
188      {
189        return data;
190      }
191    
192      /**
193       * Get the object reactivation strategy after crash.
194       *
195       * @return true ir the object is activated when activator is restarted or the
196       *         activation group is restarted. False if the object is only
197       *         activated on demand. This flag does has no effect during the normal
198       *         operation (the object is normally activated on demand).
199       */
200      public boolean getRestartMode()
201      {
202        return restart;
203      }
204    
205      /**
206       * Compare this object with another activation description for equality.
207       *
208       * @return true if all fields have the equal values, false otherwise.
209       */
210      public boolean equals(Object obj)
211      {
212        if (obj instanceof ActivationDesc)
213          {
214            ActivationDesc that = (ActivationDesc) obj;
215            return eq(groupid, that.groupid) &&
216                   eq(classname, that.classname) &&
217                   eq(location, that.location) &&
218                   eq(data, that.data)
219                   && restart == that.restart;
220          }
221        else
222          return false;
223      }
224    
225      /**
226       * Get the hash code of this object (overridden to make the returned value
227       * consistent with .equals(..).
228       */
229      public int hashCode()
230      {
231        return hash(groupid) ^ hash(classname) ^
232          hash(location) ^ hash(data);
233      }
234    
235      /**
236       * Get the hashcode of x or 0 if x == null.
237       */
238      static final int hash(Object x)
239      {
240        return x == null ? 0 : x.hashCode();
241      }
242    
243      /**
244       * Compare by .equals if both a and b are not null, compare directly if at
245       * least one of them is null.
246       */
247      static final boolean eq(Object a, Object b)
248      {
249        if (a == null || b == null)
250          return a == b;
251        else
252          return a.equals(b);
253      }
254    }