许可 – JDK源代码许可不一致

我安装了最新的JDK(1.7.0_21).当我在Eclipse中查看基础类的源代码时,例如java.lang.String,文件顶部的许可证为：

/*
 * copyright (c) 1994,2010,Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

此源代码来自JDK版本附带的src.zip文件.

当我在这里查看源代码时：
http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/7-b147/java/lang/String.java?av=f

…我看到了GPL v2.0许可证标题.

/*
 * copyright (c) 1994,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 @R_79_4045@ion or have any
 * questions.
 */

据我所知,JDK 1.7作为完全开源发布,在GPL 2.0下获得许可.

有人可以解释许可证差异吗？

最佳答案

OpenJDK在GPL 2.0下发布

来自OpenJDK FAQs

What open-source license is OpenJDK published under?

GPL v2 for almost all of the virtual machine,and GPL v2 + the
Classpath exception for the class libraries and those parts of the
virtual machine that expose public APIs.

Will Oracle change the OpenJDK licensing model?

No. The OpenJDK Community continues to thrive with contributions from
Oracle,as well as other companies,researchers,and individuals,and
the GPL-based licensing model is one large part of this success.
Oracle has no plans to change it.

Oracle JDK是在Oracle许可下发布的.
从FAQs开始

Java SE continues to be available under the Oracle Binary Code License
(BCL) free of charge.