Call a javascript from java step by step

Question

Is there a way to execute a java script from within a java program in a step-by-step manner?

I know how to call javascript from java. I know about Rhino or Beanshell. No web server involved.

What I'm trying to achieve: Have multiple scripts execute semi concurrently scheduled by a scheduler where each script gets a 'tick' every now and then in which it executes one atomic command just like in a debugger. This should also 'step into' functions and for/while loops.

I need to call the script 'tick' at a specific time (and return immediately) so real threads are no use.

So I guess i want a way to debug a script from within a java program without a debugger (and its overhead) involved. Just stepwise execution is needed.

Any ideas?

Answer 1

Yes, it is possible by using an interpreter. More specifically, you need an JavaScript interpreter that can be executed on the JVM. Rhino seems to be the most popular one.

http://www.mozilla.org/rhino/

If you are running scripts concurrently then you will need an interpreter for each concurrent script.

Answer 2

Check out these links:

https://www.mozilla.org/rhino/tutorial.html https://blogs.oracle.com/blue/entry/scripting_with_servlets_rhino_part

They will help u get started.