ant-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jaikiran Pai <>
Subject Re: ClassLoaders in JUnit Launcher Task
Date Sat, 02 Jun 2018 03:09:49 GMT

On 01/06/18 10:46 PM, Lucas Bullen wrote:
> However, when attempting to do this I run into an issue with ClassLoaders.
> JUnitLauncherTask.execute() [2] sets the thread's ClassLoader to its own or
> to an AntClassLoader, both of which do not contain the junit TestEngine's

Which test engine are you using and where are the jars for those 
located? The vintage and the jupiter test engines (part of JUnit 5) or 
any test engine for that matter, can be placed in the ANT_HOME/lib 
directory and they should be picked up. Or you can pass the -lib option 
while launching Ant to pass the location of those jars. These methods 
have been noted in the documentation of the task[1]
> Our previous way of getting around this was to create our own ClassLoader
> with the required TestEngines and set this to the current thread's
> ClassLoader to ensure that the TestEngines are found [4].
> This technique no longer works for the JUnitLauncherTask as it resets the
> ClassLoader right before executing the tests. Does anyone have a suggestion
> on how to resolve this issue?

The way JUnit 5 works, it uses the thread context classloader to find 
the test engines (and even test cases). That's why the JUnitLauncherTask 
sets it up in a manner that the right classloader is setup before 
executing the tests.

I looked at the customer classloader you pointed to, in your footnotes. 
How was that being setup in the Ant build, previously?

Overall, if I understand your question correctly - you do not want to 
add the *test engines* to the ANT_HOME/lib and neither do you want to 
pass the -lib option while launching Ant and instead want to define a 
classpath in your build file and use that classpath for finding the test 
engines? If that's the case, then yes it's currently a limitation (one 
that which Stefan had rightly brought up very early in the dev cycle of 
this task). I do plan to tackle this in a better way, but given the 
complexity involved with classloaders (both due to the nature of JUnit 5 
and Ant itself) and the fact that I  lost focus on this task for a bit, 
I haven't been able to come up with a solution. I'll look more into this 
in the upcoming days and see how we can improve this.

If I misunderstood your use case, please do let us know.



To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message