如何确定是否有“免费”或“非免费”版本的JDK11？

Question

正如现在众所周知的那样，Oracle更改了Java 11中的Java许可证，以要求为JDK的商业使用支付许可证。然而，使用OpenJDK仍然是免费的。

我的个人电脑上有一个JDK 11文件夹，如下所示：

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在这些文件夹中有什么方法可以告诉我是否有一个免费的OpenJDK版本或一个需要付费许可的Oracle版本？

Answer 1

您可以在JDK的根目录中看到一个名为release的文件。使用文本编辑器打开它，并检查它是否包含行

BUILD_TYPE="commercial"

如果是的话，那就是商业建筑了。

这是我安装11.0.1 OpenJDK时的样子：

IMPLEMENTOR="Oracle Corporation"
IMPLEMENTOR_VERSION="18.9"
JAVA_VERSION="11.0.1"
JAVA_VERSION_DATE="2018-10-16"
MODULES="java.base java.compiler java.datatransfer java.xml java.prefs java.desktop java.instrument java.logging java.management java.security.sasl java.naming java.rmi java.management.rmi java.net.http java.scripting java.security.jgss java.transaction.xa java.sql java.sql.rowset java.xml.crypto java.se java.smartcardio jdk.accessibility jdk.internal.vm.ci jdk.management jdk.unsupported jdk.internal.vm.compiler jdk.aot jdk.internal.jvmstat jdk.attach jdk.charsets jdk.compiler jdk.crypto.ec jdk.crypto.cryptoki jdk.crypto.mscapi jdk.dynalink jdk.internal.ed jdk.editpad jdk.hotspot.agent jdk.httpserver jdk.internal.le jdk.internal.opt jdk.internal.vm.compiler.management jdk.jartool jdk.javadoc jdk.jcmd jdk.management.agent jdk.jconsole jdk.jdeps jdk.jdwp.agent jdk.jdi jdk.jfr jdk.jlink jdk.jshell jdk.jsobject jdk.jstatd jdk.localedata jdk.management.jfr jdk.naming.dns jdk.naming.rmi jdk.net jdk.pack jdk.rmic jdk.scripting.nashorn jdk.scripting.nashorn.shell jdk.sctp jdk.security.auth jdk.security.jgss jdk.unsupported.desktop jdk.xml.dom jdk.zipfs"
OS_ARCH="x86_64"
OS_NAME="Windows"
SOURCE=".:8513ac27b651"

对于相应的Oracle JDK：

BUILD_TYPE="commercial"
IMPLEMENTOR="Oracle Corporation"
IMPLEMENTOR_VERSION="18.9"
JAVA_VERSION="11.0.1"
JAVA_VERSION_DATE="2018-10-16"
MODULES="java.base java.compiler java.datatransfer java.xml java.prefs java.desktop java.instrument java.logging java.management java.security.sasl java.naming java.rmi java.management.rmi java.net.http java.scripting java.security.jgss java.transaction.xa java.sql java.sql.rowset java.xml.crypto java.se java.smartcardio jdk.accessibility jdk.internal.vm.ci jdk.management jdk.unsupported jdk.internal.vm.compiler jdk.aot jdk.internal.jvmstat jdk.attach jdk.charsets jdk.compiler jdk.crypto.ec jdk.crypto.cryptoki jdk.crypto.mscapi jdk.dynalink jdk.internal.ed jdk.editpad jdk.hotspot.agent jdk.httpserver jdk.internal.le jdk.internal.opt jdk.internal.vm.compiler.management jdk.jartool jdk.javadoc jdk.jcmd jdk.management.agent jdk.jconsole jdk.jdeps jdk.jdwp.agent jdk.jdi jdk.jfr jdk.jlink jdk.jshell jdk.jsobject jdk.jstatd jdk.localedata jdk.management.jfr jdk.naming.dns jdk.naming.rmi jdk.net jdk.pack jdk.rmic jdk.scripting.nashorn jdk.scripting.nashorn.shell jdk.sctp jdk.security.auth jdk.security.jgss jdk.unsupported.desktop jdk.xml.dom jdk.zipfs"
OS_ARCH="x86_64"
OS_NAME="Windows"
SOURCE=".:657c1504057c open:8513ac27b651"

因此，除了“商业”行之外，它还命名了另一个源存储库。考虑到它有一些额外的特性，这是有意义的。

您还可以在.h目录中打开其中一个include文件并查看头文件。商业版本的标题以

/*
 * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

而免费版本以

/*
 * Copyright (c) 1999, 2017, 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.
 */

同样的区别也适用于lib/src.zip存档中的所有lib/src.zip文件，但是提取它们不再是“快速检查”了。