| /* ObjectId.java -- object IDs |
| Copyright (C) 2005, 2006 Free Software Foundation |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath 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, or (at your option) |
| any later version. |
| |
| GNU Classpath 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. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.classpath.jdwp.id; |
| |
| import gnu.classpath.jdwp.JdwpConstants; |
| import gnu.classpath.jdwp.exception.InvalidObjectException; |
| |
| import java.io.DataOutputStream; |
| import java.io.IOException; |
| |
| /** |
| * This is a base class for all ObjectID-like entities in JDWP, |
| * inculding Objects, ClassObject, ClassLoader, Thread, ThreadGroup, |
| * etc. |
| * |
| * @author Keith Seitz <keiths@redhat.com> |
| */ |
| public class ObjectId |
| extends JdwpId |
| { |
| /** |
| * The object class that this id represents |
| */ |
| public static final Class typeClass = Object.class; |
| |
| // Handle to disable garbage collection |
| private Object _handle; |
| |
| /** |
| * Constructs a new <code>ObjectId</code> |
| */ |
| public ObjectId () |
| { |
| super (JdwpConstants.Tag.OBJECT); |
| } |
| |
| /** |
| * Constructs a new <code>ObjectId</code> of the |
| * given type. |
| * |
| * @param tag the tag of this type of object ID |
| */ |
| public ObjectId (byte tag) |
| { |
| super (tag); |
| } |
| |
| /** |
| * Returns the object referred to by this ID |
| * |
| * @returns the object |
| * @throws InvalidObjectException if the object was garbage collected |
| * or is invalid |
| */ |
| public Object getObject () |
| throws InvalidObjectException |
| { |
| Object obj = _reference.get (); |
| if (obj == null) |
| throw new InvalidObjectException (_id); |
| |
| return obj; |
| } |
| |
| /** |
| * Writes the id to the stream |
| * |
| * @param outStream the stream to which to write |
| * @throws IOException when an error occurs on the <code>OutputStream</code> |
| */ |
| public void write (DataOutputStream outStream) |
| throws IOException |
| { |
| // All we need to do is write out our id as an 8-byte integer |
| outStream.writeLong (_id); |
| } |
| |
| /** |
| * Disable garbage collection on object |
| */ |
| public void disableCollection () |
| throws InvalidObjectException |
| { |
| _handle = getObject (); |
| } |
| |
| /** |
| * Enable garbage collection on object |
| */ |
| public void enableCollection () |
| { |
| _handle = null; |
| } |
| } |