--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/src/share/classes/sun/jvm/hotspot/oops/DefaultMetadataVisitor.java	Sat Sep 01 13:25:18 2012 -0400
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+package sun.jvm.hotspot.oops;
+
+import sun.jvm.hotspot.debugger.Address;
+
+/** A DefaultMetadataVisitor implements basic no-op MetadataVisitor
+    functionality except that the setObj() and getObj() methods are
+    implemented properly. */
+abstract public class DefaultMetadataVisitor implements MetadataVisitor {
+  private Metadata obj;
+
+  public void prologue()                        {}
+
+  // Called after visiting an object
+  public void epilogue()                        {}
+
+  public void setObj(Metadata obj) {
+    this.obj = obj;
+  }
+
+  public Metadata getObj() {
+    return obj;
+  }
+
+  // Callback methods for each field type in an object
+  abstract public void doMetadata(MetadataField field, boolean isVMField);
+  public void doOop(OopField field, boolean isVMField)         {}
+  public void doOop(NarrowOopField field, boolean isVMField)   {}
+  public void doByte(ByteField field, boolean isVMField)       {}
+  public void doChar(CharField field, boolean isVMField)       {}
+  public void doBoolean(BooleanField field, boolean isVMField) {}
+  public void doShort(ShortField field, boolean isVMField)     {}
+  public void doInt(IntField field, boolean isVMField)         {}
+  public void doLong(LongField field, boolean isVMField)       {}
+  public void doFloat(FloatField field, boolean isVMField)     {}
+  public void doDouble(DoubleField field, boolean isVMField)   {}
+  public void doCInt(CIntField field, boolean isVMField)       {}
+}