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Diffstat (limited to 'gcc-4.4.3/libjava/classpath/gnu/classpath/jdwp/id/NullObjectId.java')
-rw-r--r-- | gcc-4.4.3/libjava/classpath/gnu/classpath/jdwp/id/NullObjectId.java | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/gcc-4.4.3/libjava/classpath/gnu/classpath/jdwp/id/NullObjectId.java b/gcc-4.4.3/libjava/classpath/gnu/classpath/jdwp/id/NullObjectId.java new file mode 100644 index 000000000..0e7b5e39c --- /dev/null +++ b/gcc-4.4.3/libjava/classpath/gnu/classpath/jdwp/id/NullObjectId.java @@ -0,0 +1,79 @@ +/* NullObjectId.java -- special objectId for null values + Copyright (C) 2007 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 +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.exception.InvalidObjectException; +import gnu.classpath.jdwp.util.NullObject; + +import java.lang.ref.SoftReference; + +/** + * This is a special case of an ObjectId. When a varaible slot contains + * null as its value, this is a valid value despite the fact that it does + * not reference an object. To represent this, this will always be the id + * of the NullObject (0). + * + * @author Kyle Galloway <kgallowa@redhat.com> + */ +public class NullObjectId + extends ObjectId +{ + /** + * The object class that this id represents + */ + public static final Class typeClass = NullObject.class; + + /** + * Constructs a new <code>NullObjectId</code> + */ + public NullObjectId() + { + super(); + setId((long) 0); + _reference = new SoftReference<NullObject>(new NullObject()); + try + { + disableCollection(); + } + catch(InvalidObjectException ex) + { + //This will not happen + } + } + +} |