How to emulate Oracle Java with OpenJDK?

Question

I have a java app, which does not wont to work:

Please install Java JRE 1.7.0_45 or a more recent version 

I think it checks java version and vendor. Does openJDK have special option to emulate vendor. I don't want to install Oracle Java.

Here is my output of java -version:

openjdk version "1.8.0_74" OpenJDK Runtime Environment (build 1.8.0_74-b02) OpenJDK 64-Bit Server VM (build 25.74-b02, mixed mode) 

---

Not a cool solution but works

I have installed Oracle JRE near OpenJDK. On Manjaro (Arch) Linux it is very simple

yaourt -S jre 

After instalation complete it will ask you to select default java. archlinux-java status shows installed Java Machines. I have written litle script to run my capricious app with oracle jre:

#!/bin/sh ## Get first JRE from jrepath=$(archlinux-java status | grep 'jre' -m1 ) ## remove spaces jrepath=$(echo $jrepath | grep -v -e '^$') ## Compose full path jrepath="/usr/lib/jvm/$jrepath/bin/java" ## Check if it works DEBUG ${jrepath} -version ${jrepath} -jar path/to/STM32CubeMX 

In addition I wanted to run app from the folder where script is:

## Where is script pushd `dirname $0` > /dev/null SCRIPTPATH=`pwd -P` ## -P to resolve symlinks popd > /dev/null ${jrepath} -jar $SCRIPTPATH/STM32CubeMX 

Answer 1

No, OpenJDK doesn't do that. Each has a vendor property to identify itself.

The value itself is stored within the JAR-files, e.g., as part of the manifest (see Oracle's documentation for instance). Since the JAR-files are signed, and the API generally prohibits you from changing a system property, there is little to be done to change the version.

Further reading:

• How can I tell whether Java is Sun / Oracle / OpenJDK? [duplicate]
• System Properties

Answer 2

If your app is looking or Oracle's Java, have you considered that it might be for a reason? If you think that the java version really doesn't matter, you can write a script front end to your java and have it imitate the Oracle java when the version was asked. But I am quite sure version will not be the only thing your app will be checking and you will find yourself writing a very very complex script to filter a lot of different things. It is an idea but I personally do not suggest implementing it.