/* ObjectId.java -- object IDs Copyright (C) 2005 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 */ 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 ObjectId */ public ObjectId () { super (JdwpConstants.Tag.OBJECT); } /** * Constructs a new ObjectId of the * given type. * * @param tag the tag of this type of object ID */ public ObjectId (byte tag) { super (tag); } /** * Returns the size of this id type */ public int size () { return 8; } /** * 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 OutputStream */ 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; } }
