Make .bat start script honor -J and -D arguments.

[gourlaysama]

This makes the .bat start script parse and use -J and -D arguments.

Specifically:

• Parameters starting with -J are stripped of the prefix, unquoted if
  necessary and appended to %JAVA_OPTS%.
• Parameters starting with -D are unquoted if necessary and then
  appended to the others. The right-hand side of a property can be
  quoted or not.
• The exact arguments passed to the script are also given as-is to the
  main class (using %*), so, as before, the main class should ignore
  arguments starting with -J and -D. This could be improved by manually
  parsing all arguments (not just -J and -D), but this is a mine field
  when it comes to quoting and delimiters...

This is adapted from my similar contribution to scala 2.10, see
scala/scala#2767.

---

I've wanted to do this for some time, so here it is. This is also somewhat related to #155.

[lightbend-cla-validator]

Hi @gourlaysama,

Thank you for your contribution! We really value the time you've taken to put this together.

Before we proceed with reviewing this pull request, please sign the Typesafe Contributors License Agreement:

http://typesafe.com/contribute/cla

[gourlaysama]

I signed the CLA :-)

[muuki88]

Thanks a lot @gourlaysama ! Bat-Gurus are always welcome :) I will try this on windows as I only get the intention of your code (mostly through the comments). Looking at the conversion of scala/scala#2767 everything should be fine.

[jsuereth]

Nice, so this loop could do more sorts of arg parsing than just -D vs. -J.

[jsuereth]

This LGTM. we don't have automated windows tests though, so I may need to check this out manually to try it.

[muuki88]

Okay, I tested this (Windows 7). My App looks like this

println(System.getProperty("test", "no value"))
println("Max Memory: " + (Runtime.getRuntime.maxMemory / (1024*1024)) + " Mb")

Results for System Properties

Parameters	Expected Output	Output	Result
-Dtest=value	value	value	OK
-J-Dtest=value	value	(nothing, not even the fallback value)	Should this work?
-Dtest="long value"	long value	Powershell expects input with >>	I think OK
"-Dtest="long value"	long value	long value	OK

Results for jvm properties

everything worked as expected

[gourlaysama]

• Good point about -J-D.... I didn't consider it since that was what -D was all about. I guess it should still work, for the sake of consistency.
• -Dtest="long value" works for me, both in cmd and powershell.
• I just found a powershell-only bug: -Dcom.whatever.property=v is split by powershell into two arguments as -Dcom and .whatever.property=v, whereas CMD splits it as -Dcom.whatever.property and v (with the = separator gone). The script currently expects the latter, so the property is not set when run from powershell. The workaround is to quote the whole thing. I am looking into fixing that. The script is going to get uglier...

I'll ping you when I update the PR.

[gourlaysama]

Hum, it seems that the problem with -D java properties and powershell is a well known problem I just rediscovered, and that it is up to the caller to properly escape the - with a backtick or quote the whole thing, as in:

./test `-Dcom.whatever.property=v

or

./test "-Dcom.whatever.property=v"

So anyway, that's not really a bug in the bat file. I'll just update the script with proper support for -J-D, and that should be it.

[gourlaysama]

@muuki88 I updated the script. Here is a little summary:

• -Dfoo=42, "Dfoo=42" and -Dfoo="42" work in both CMD and Powershell,
• -Dfoo.bar=42 and -Dfoo.bar="42" only work in CMD, PS requires to backtick-escape the -,
• "-Dfoo.bar=42" work both in CMD and Powershell,
• all the above is the same with -J-D instead of -D.

[muuki88]

Awesome! Thanks a lot for your effort. @jsuereth or I will try to reproduce the results an then merge it.

[gourlaysama]

ping @muuki88: did you get a chance to test this?

[muuki88]

no! unfortunatly not. Now the 0.7.0 release is out, this is the next thing to test. Sorry for the long delay :/

[muuki88]

Sorry for the long delay. Thanks for your bash magic :)