diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/java.base/share/classes/java/lang/Number.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/lang/Number.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 1994, 2015, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.lang;
+
+/**
+ * The abstract class {@code Number} is the superclass of platform
+ * classes representing numeric values that are convertible to the
+ * primitive types {@code byte}, {@code double}, {@code float}, {@code
+ * int}, {@code long}, and {@code short}.
+ *
+ * The specific semantics of the conversion from the numeric value of
+ * a particular {@code Number} implementation to a given primitive
+ * type is defined by the {@code Number} implementation in question.
+ *
+ * For platform classes, the conversion is often analogous to a
+ * narrowing primitive conversion or a widening primitive conversion
+ * as defined in <cite>The Java&trade; Language Specification</cite>
+ * for converting between primitive types.  Therefore, conversions may
+ * lose information about the overall magnitude of a numeric value, may
+ * lose precision, and may even return a result of a different sign
+ * than the input.
+ *
+ * See the documentation of a given {@code Number} implementation for
+ * conversion details.
+ *
+ * @author      Lee Boynton
+ * @author      Arthur van Hoff
+ * @jls 5.1.2 Widening Primitive Conversions
+ * @jls 5.1.3 Narrowing Primitive Conversions
+ * @since   1.0
+ */
+public abstract class Number implements java.io.Serializable {
+    /**
+     * Returns the value of the specified number as an {@code int}.
+     *
+     * @return  the numeric value represented by this object after conversion
+     *          to type {@code int}.
+     */
+    public abstract int intValue();
+
+    /**
+     * Returns the value of the specified number as a {@code long}.
+     *
+     * @return  the numeric value represented by this object after conversion
+     *          to type {@code long}.
+     */
+    public abstract long longValue();
+
+    /**
+     * Returns the value of the specified number as a {@code float}.
+     *
+     * @return  the numeric value represented by this object after conversion
+     *          to type {@code float}.
+     */
+    public abstract float floatValue();
+
+    /**
+     * Returns the value of the specified number as a {@code double}.
+     *
+     * @return  the numeric value represented by this object after conversion
+     *          to type {@code double}.
+     */
+    public abstract double doubleValue();
+
+    /**
+     * Returns the value of the specified number as a {@code byte}.
+     *
+     * <p>This implementation returns the result of {@link #intValue} cast
+     * to a {@code byte}.
+     *
+     * @return  the numeric value represented by this object after conversion
+     *          to type {@code byte}.
+     * @since   1.1
+     */
+    public byte byteValue() {
+        return (byte)intValue();
+    }
+
+    /**
+     * Returns the value of the specified number as a {@code short}.
+     *
+     * <p>This implementation returns the result of {@link #intValue} cast
+     * to a {@code short}.
+     *
+     * @return  the numeric value represented by this object after conversion
+     *          to type {@code short}.
+     * @since   1.1
+     */
+    public short shortValue() {
+        return (short)intValue();
+    }
+
+    /** use serialVersionUID from JDK 1.0.2 for interoperability */
+    private static final long serialVersionUID = -8742448824652078965L;
+}