Is there a way to interrogate a JVM/JRE for its license?

Question

Oracle changed the license for its Java releases:

• 8u201/8u202 and prior: Oracle Binary Code License (OBCL) Agreement
• 8u211/8u212 and later: Oracle Technology Network (OTN) License Agreement

I suppose that all Oracle releases of Java 7 and below were OBCL; I'm not sure if there were any Oracle Java 9+ releases under that old license.

Of course, other Java distributions (OpenJDK, etc.) have still other licenses.

Is there a way for a running program to determine the license of the underlying JVM/JRE? Motivation: I'd like to warn users of my program when they're using my program on a JVM/JRE of specific license(s).

I've been unable find to find any standard system property with this information, and I also looked in the manifests of the JARs that constitute the JRE.

There are a couple places that provide structured access to the Java version:

• https://commons.apache.org/proper/commons-lang/javadocs/api-3.9/org/apache/commons/lang3/SystemUtils.html → IS_JAVA_1_8, etc.
• https://commons.apache.org/proper/commons-lang/javadocs/api-3.9/org/apache/commons/lang3/JavaVersion.html
• https://docs.oracle.com/javase/9/docs/api/java/lang/Runtime.Version.html

The former doesn't get down to the detail of the the update number, and the latter is only available in Java 9+. In any case, both still require some other resource to map known Java versions to their respective licenses.

Also: I'm aware of Oracle's latest recommendation of bundling a JRE with one's application, and that this issue can be avoided that way.

Answer 1

${java.home}/LICENSE

Oracle Java 7 and 8 contain a file ${java.home}/LICENSE. For 1.7.0_80 and 1.8.0_152, the content is:

Please refer to http://java.com/license

After 6 HTTP redirects, that currently leads to https://www.oracle.com/downloads/licenses/binary-code-license.html, which describes "Oracle Binary Code License Agreement for the Java SE Platform Products and JavaFX."

${java.home}/LICENSE in Oracle Java 1.8.0_221 says:

Please refer to https://java.com/bc_license

After 3 HTTP redirects, that currently leads to https://www.oracle.com/downloads/licenses/javase-license1.html, which describes "Oracle Technology Network License Agreement for Oracle Java SE."

${java.home}/LICENSE in Oracle Java 1.8.0_251 says:

Please refer to https://java.com/otnlicense

Oracle and OpenJDK Java releases 9+ don't provide ${java.home}/LICENSE.

${java.home}/release

All Java releases have a file ${java.home}/release, which looks like this for Oracle Java 11:

BUILD_TYPE="commercial"
IMPLEMENTOR="Oracle Corporation"
...

and this for Ubuntu's openjdk-11-jre-headless package (version 11.0.4+11-1ubuntu2~18.04.3):

IMPLEMENTOR="Ubuntu"
...

There is no BUILD_TYPE value in the case of the Ubuntu package.

Other results with downloads from java.net:

jre-8u221-linux-i586.tar.gz and jdk-8u251-linux-i586.tar.gz :

BUILD_TYPE="commercial"

jdk-9+181_linux-x64_ri.zip:

IMPLEMENTOR="N/A"

serverjre-9_linux-x64_bin.tar.gz (java -version says build 9+181):

BUILD_TYPE="commercial"
IMPLEMENTOR="Oracle Corporation"

openjdk-10+44_linux-x64_bin_ri.tar.gz:

IMPLEMENTOR="Oracle Corporation"
JAVA_VERSION_DATE="2018-03-20"

jdk-10_linux-x64_bin_ri.tar.gz (java -version says build 10+44):

IMPLEMENTOR="Oracle Corporation"
JAVA_VERSION_DATE="2018-03-20"

openjdk-11+28_linux-x64_bin.tar.gz:

IMPLEMENTOR="Oracle Corporation"
JAVA_VERSION_DATE="2018-09-25"

jdk-11.0.4_linux-x64_bin.tar.gz:

BUILD_TYPE="commercial"
IMPLEMENTOR="Oracle Corporation"
JAVA_VERSION_DATE="2019-07-16"

openjdk-12.0.2_linux-x64_bin.tar.gz:

IMPLEMENTOR="Oracle Corporation"
JAVA_VERSION_DATE="2019-07-16"

Oracle Java 7 and 8 installed on Ubuntu via the oracle-java7-installer and oracle-java8-installer packages also provide ${java.home}/release, containing:

BUILD_TYPE="commercial"

${java.home}/legal/java.base/LICENSE

Java 9+ distributions contain a ${java.home}/legal directory. Examining ${java.home}/legal/java.base/LICENSE:

• openjdk-9+181_linux-x64_ri.zip: GPLv2 + classpath exception
• jdk-9+181_linux-x64_ri.zip: GPLv2 + classpath exception
• serverjre-9_linux-x64_bin.tar.gz: "Please refer to http://java.com/license"
• openjdk-10+44_linux-x64_bin_ri.tar.gz: GPLv2 + classpath exception
• jdk-10_linux-x64_bin_ri.tar.gz: GPLv2 + classpath exception
• openjdk-11+28_linux-x64_bin.tar.gz: GPLv2 + classpath exception (legal/*/LICENSE are identical)
• jdk-11.0.4_linux-x64_bin.tar.gz: "Please refer to https://java.com/otnlicense" (legal/*/LICENSE are identical)
• openjdk-12.0.2_linux-x64_bin.tar.gz: GPLv2 + classpath exception

Ubuntu's openjdk-11-jre-headless 11.0.4+11-1ubuntu2~18.04.3 provides no ${java.home}/legal/*/LICENSE.

Summary

Strangely, it looks like "https://java.com/bc_license" in ${java.home}/LICENSE is a good indication of an OTN-licensed JRE. I suppose it was a mistake that for Oracle releases after March 16, 2019, the URL in LICENSE changed from "http://java.com/license" to "https://java.com/bc_license"; they should have changed it to "https://java.com/otnlicense". Their remedy was to make https://java.com/bc_license redirect to the OTN document.

A strong hint is when ${java.home}/legal/java.base/LICENSE contains "Please refer to https://java.com/otnlicense".

A weaker hint is the combination of:

• IMPLEMENTOR="Oracle Corporation",
• BUILD_TYPE="commercial", and
• JAVA_VERSION_DATE="2019-04-16" or later.

More robust answers welcome though!