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

[Rony G. Flatscher]

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