--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/util/zip/Checksum.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,60 @@
+/*
+ * Copyright 1996-1999 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.util.zip;
+
+/**
+ * An interface representing a data checksum.
+ *
+ * @author      David Connelly
+ */
+public
+interface Checksum {
+    /**
+     * Updates the current checksum with the specified byte.
+     *
+     * @param b the byte to update the checksum with
+     */
+    public void update(int b);
+
+    /**
+     * Updates the current checksum with the specified array of bytes.
+     * @param b the byte array to update the checksum with
+     * @param off the start offset of the data
+     * @param len the number of bytes to use for the update
+     */
+    public void update(byte[] b, int off, int len);
+
+    /**
+     * Returns the current checksum value.
+     * @return the current checksum value
+     */
+    public long getValue();
+
+    /**
+     * Resets the checksum to its initial value.
+     */
+    public void reset();
+}