Peculiar classpath problem (FileNotFoundException), but path looks correct

[Johannes Maier]

Hello,

I'm trying to develop a bot with Kotlin using IntelliJ IDEA 2017.3. I have
got it configured, I can compile, I can build a .jar for my robot which
works fine; so far, so good!
I'm hitting a wall when trying to run the development version of my robot
in robocode though. When the Kotlin runtime is missing from the classpath,
the bot won't even be loaded (and I get errors in the output when starting
robocode), but that is expected. Now I'm using the following (partly
generated by IntelliJ) command to start robocode:

"C:\Program Files\Java\jdk1.8.0_66\bin\java"
-Xmx512M
-Dsun.io.useCanonCaches=false
-cp "libs\robocode.jar;C:\Program Files\JetBrains\IntelliJ IDEA Community
Edition 2017.3\plugins\Kotlin\kotlinc\lib\kotlin-reflect.jar;C:\Program
Files\JetBrains\IntelliJ IDEA Community Edition
2017.3\plugins\Kotlin\kotlinc\lib\kotlin-stdlib.jar;C:\Program
Files\JetBrains\IntelliJ IDEA Community Edition
2017.3\plugins\Kotlin\kotlinc\lib\kotlin-stdlib-jdk7.jar;C:\Program
Files\JetBrains\IntelliJ IDEA Community Edition
2017.3\plugins\Kotlin\kotlinc\lib\kotlin-stdlib-jdk8.jar"
"-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition
2017.3\lib\idea_rt.jar=49977:C:\Program Files\JetBrains\IntelliJ IDEA
Community Edition 2017.3\bin"
-Dfile.encoding=UTF-8 robocode.Robocode

Using this, I can load the robot just fine, even if it uses the Kotlin
runtime. No errors until I run it, then I see the following in the output:

java.io.FileNotFoundException:
D:\projects\bots\Oldur\out\production\Oldur\kotlin\jvm\internal\Intrinsics.class
(The system cannot find the path specified)
at java.io.FileInputStream.open0(Native Method)
at java.io.FileInputStream.open(FileInputStream.java:195)
at java.io.FileInputStream.<init>(FileInputStream.java:138)
at java.io.FileInputStream.<init>(FileInputStream.java:93)
at
sun.net.www.protocol.file.FileURLConnection.connect(FileURLConnection.java:90)
at
sun.net.www.protocol.file.FileURLConnection.getInputStream(FileURLConnection.java:188)
at
net.sf.robocode.host.security.RobotClassLoader$1.run(RobotClassLoader.java:166)
at
net.sf.robocode.host.security.RobotClassLoader$1.run(RobotClassLoader.java:152)
at java.security.AccessController.doPrivileged(Native Method)
at
net.sf.robocode.host.security.RobotClassLoader.findLocalResource(RobotClassLoader.java:152)
at
net.sf.robocode.host.security.RobotClassLoader.loadRobotClassLocaly(RobotClassLoader.java:137)
at
net.sf.robocode.host.security.RobotClassLoader.loadClass(RobotClassLoader.java:98)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at kenran.Oldur.onHitByBullet(Oldur.kt)
at robocode.HitByBulletEvent.dispatch(HitByBulletEvent.java:167)
at robocode.Event$HiddenEventHelper.dispatch(Event.java:259)
at net.sf.robocode.security.HiddenAccess.dispatch(HiddenAccess.java:191)
at net.sf.robocode.host.events.EventManager.dispatch(EventManager.java:422)
at
net.sf.robocode.host.events.EventManager.processEvents(EventManager.java:376)
at
net.sf.robocode.host.proxies.BasicRobotProxy.executeImpl(BasicRobotProxy.java:423)
at
net.sf.robocode.host.proxies.BasicRobotProxy.rescan(BasicRobotProxy.java:336)
at robocode.Robot.scan(Robot.java:776)
at kenran.Oldur.run(Oldur.kt:10)
at
net.sf.robocode.host.proxies.HostingRobotProxy.callUserCode(HostingRobotProxy.java:274)
at
net.sf.robocode.host.proxies.HostingRobotProxy.run(HostingRobotProxy.java:221)
at net.sf.robocode.host.proxies.BasicRobotProxy.run(BasicRobotProxy.java:44)
at java.lang.Thread.run(Thread.java:745)

Mind you, the bot is running fine and seems to do everything correctly!
This just leads to the robot not being able to stop at the end of the
round... which means I can't use the rumble. I don't understand why
robocode seems to be looking for the Intrinsics.class file in the place
it's looking, as it seems to find and use it correctly throughout the
matches and when loading the robot class in the beginning. Here is the
output I see in the bot log:

=========================
Round 1 of 10
=========================
SYSTEM: kenran.Oldur 0.05* has died
=========================
Round 2 of 10
=========================
java.lang.IllegalMonitorStateException
at
java.util.concurrent.locks.ReentrantLock$Sync.tryRelease(ReentrantLock.java:151)
at
java.util.concurrent.locks.AbstractQueuedSynchronizer.release(AbstractQueuedSynchronizer.java:1261)
at java.util.concurrent.locks.ReentrantLock.unlock(ReentrantLock.java:457)
at java.util.concurrent.DelayQueue.take(DelayQueue.java:234)
at javax.swing.TimerQueue.run(TimerQueue.java:171)
at java.lang.Thread.run(Thread.java:745)
SYSTEM: This robot has been stopped. No score will be generated.
SYSTEM: game aborted.


I can work around this issue by just putting the Kotlin runtime classes
where robocode is looking, but that is kind of unsatisfactory.

As a reference, here is a simple robot that shows this behavior (though I
of course understand if noone wants to go through the trouble to try it as
it uses a different language):

class Oldur : AdvancedRobot() {
override fun run() {
while (true) {
scan()
}
}

override fun onScannedRobot(e: ScannedRobotEvent) {
}

override fun onHitByBullet(e: HitByBulletEvent) {
}
}

Two things with this robot that seem strange/buggy to me when running it:
1) If I add a ? behind HitByBulletEvent and thus making it nullable, the
bot works fine
2) The stack trace always shows the onHitByBullet event as the problem.
onScannedRobot doesn't seem to have this problem at all, even though it
also uses a non-nullable event argument.

Any help with this would be greatly appreciated!

[t***@gmail.com]

I'm having a similar issue. Robots cannot find the classes from libraries
on my classpath upon runtime. Did you find a workaround?

[fnl]

Hi guys,

Cool that you are using Kotlin for developing Robocode robots. I like
Kotlin, and think it is a good match for developing bots in Robocode. :-)

I think the problem you see is due to a missing Kotlin runtime jar in the
classpath, as it looks for the class kotlin.jvm.internal.Intrinsics.

I found a similar issue on Stack Overflow:
https://stackoverflow.com/questions/43425367/mapdb-classnotfoundexception-kotlin-jvm-internal-intrinsics

This points to another article, which has a fix/work-around:
https://dzone.com/articles/exercises-in-kotlin-part-1-getting-started

I hope this helps?

Cheers,
- Flemming

Post by t***@gmail.com
I'm having a similar issue. Robots cannot find the classes from libraries
on my classpath upon runtime. Did you find a workaround?

[Tom Plum]

Hi Flemming,

I'm not actually using Kotlin for development. I did post on StackOverflow
myself shortly.

Would you mind taking a quick look? It's for my final year university
dissertation and it's really holding me back!
https://stackoverflow.com/questions/49094453/robocode-libraries-cannot-be-found-by-robot-upon-runtime


Kind Regards,
Tom

Post by fnl
Hi guys,
Cool that you are using Kotlin for developing Robocode robots. I like
Kotlin, and think it is a good match for developing bots in Robocode. :-)
I think the problem you see is due to a missing Kotlin runtime jar in the
classpath, as it looks for the class kotlin.jvm.internal.Intrinsics.
https://stackoverflow.com/questions/43425367/mapdb-classnotfoundexception-kotlin-jvm-internal-intrinsics
https://dzone.com/articles/exercises-in-kotlin-part-1-getting-started
I hope this helps?
Cheers,
- Flemming

Post by t***@gmail.com
I'm having a similar issue. Robots cannot find the classes from libraries
on my classpath upon runtime. Did you find a workaround?

[fnl]

Hi Tom, I posted by answer on Stack Overflow.

I am not sure if it will work for you. But at least you should try out my
suggestions. :-)

- Flemming

Post by Tom Plum
Hi Flemming,
I'm not actually using Kotlin for development. I did post on StackOverflow
myself shortly.
Would you mind taking a quick look? It's for my final year university
dissertation and it's really holding me back!
https://stackoverflow.com/questions/49094453/robocode-libraries-cannot-be-found-by-robot-upon-runtime
Kind Regards,
Tom

Post by fnl
Hi guys,
Cool that you are using Kotlin for developing Robocode robots. I like
Kotlin, and think it is a good match for developing bots in Robocode. :-)
I think the problem you see is due to a missing Kotlin runtime jar in the
classpath, as it looks for the class kotlin.jvm.internal.Intrinsics.
https://stackoverflow.com/questions/43425367/mapdb-classnotfoundexception-kotlin-jvm-internal-intrinsics
https://dzone.com/articles/exercises-in-kotlin-part-1-getting-started
I hope this helps?
Cheers,
- Flemming

Post by t***@gmail.com
I'm having a similar issue. Robots cannot find the classes from
libraries on my classpath upon runtime. Did you find a workaround?