CODEWITHSUNDEEP
rubyruntimejrubyrequire
tubu13
tubu13

Reputation: 934

JRuby requires jar file in runtime

I'm trying to find a way to include a jar file in my JRuby program in runtime.

Explanation: I have the line

require 'path/to/jarSome.jar'

Now the problem is that this file doesn't exist when the program starts running, the program creates that jar file (and I'm using it later on the same program)

Is there a way to include the jar in run time? something like this:

# Some ruby code
# create/put the jar file in the location
require/import/load the jar file.???

Upvotes: 1

Views: 1841

Answers (2)

tubu13
tubu13

Reputation: 934

I think I found out the answer:

class_loader = JRuby.runtime.jruby_class_loader
class_loader.add_url(java.io.File.new('path/to/jarSome.jar'))

Upvotes: 1

jrochkind
jrochkind

Reputation: 23317

You can also execute the require statement whenever you want -- ruby is dynamic like that, you don't need to execute it on program boot or source file load. 

def create_and_require_jar
  do_something_to_create_jar
  require 'the/jar/i/created.jar'
end

If your problem is that the jar doesn't exist yet at the moment you execute the require -- simply change when you execute the require, to be after you've created the .jar.

While I have never created a .jar dynamically to be used by the same program that created it (and I'm not sure why you'd want to), I have done a require of a .jar in Jruby, as part of dynamic logic where sometimes I require it and sometimes I don't, and do the require inside conditional logic, not immediately on program boot. It's worked fine.

And I've found it super nice that you can do this in Jruby, conditional loading of a Jar based on program logic (first checking to see if the jar exists, or based on arguments or configuration) -- if you can do that in straight Java, I don't know how, although you might be able to!

Upvotes: 1

Related Questions