A question ad JDK 9 or: how to make all javax.script engines available to all Java apps in JDK 9?

[Remi Forax]

Hi Rony,
does javax.script discovery implementation use java.util.ServiceLoader 
convention ?

If the answer is yes, then it will work out of the box.

cheers,
Rémi

On 01/12/2015 05:09 PM, Rony G. Flatscher wrote:
> Hi there,
>
> reading <http://openjdk.java.net/jeps/220 this is a question or maybe a request for information
> regarding the removal of the "extension" mechanism and what can be used instead?
>
> There is one particular use-case that I regard to be of tremendeous importance for the Java world,
> recognizing that many Java movers and shakers do not really realize ;) : making javax.script
> scripting languages available to Java applications.
>
> Background: I served as an expert on JSR-223 which defined javax.script (personal background: Apache
> Commons BSF scripting framework, BSF4ooRexx a JNI-bridge to the opensource ooRexx.org scripting
> language, which itself is implemented in C++, creator of the Apache OpenOffice AOO ooRexx plugin
> using the AOO Java scripting framework, teaching at a Business University among other things
> scripting, ...).
>
> "javax.script" defines a discovery mechanism which allows a Java app to enumerate all available
> scripting engines. This way all discoverable (= installed) javax.script engines are available to any
> Java app and script/macro programmers. As a result the (end) users become able to pick the script
> language they wish to use to create macros/scripts for their Java application. [An example would be
> Apache OpenOffice (AOO), which allows using any script language, provided it is made available via
> AOOs Java based scripting framework, like BeanShell, JavaScript, ooRexx, et.al.]
>
> Please note, that a Java application developer may not even (and need not) know in advance which
> javax.script engines will be available on a target installation, just that it is rather easy to
> enumerate the javax.script engines available to it and allow the (end) user programmer to pick one
> for creating scripts targeted at the Java application.
>
> ---
>
> Currently (in pre-Java 9 environments), if one wishes to use javax.script engines (e.g. in web
> browsers via the Oracle browser Java plugin and in parallel in other Java apps), one can make any
> javax.script engine available by placing it in the Java "extension" directory, which works even
> then, when Java apps (like the Oracle browser Java plugin or AOO) does not honor the CLASSPATH
> environment variable.
>
> Now, having learned that JDK 9 will remove the "extension" mechanism, I am very interested in
> learning what alternatives are discussed, planned for Java 9 to enable this particular important
> use-case: making javax.script engines (packaged as jars) available to any Java app!
>
> TIA,
>
> ---rony
>
>