ASM library needs update for every JDK release

[Foorack]

minecraft@ck1:~/dev$ java -Xms768M -XX:+UseG1GC -jar glowstone.jar                                                                              
19:31:01 [INFO] This server is running Glowstone version 2018.4.0.74959d8 (MC: 1.12.2) (Implementing API version 1.12.2-R4.0-SNAPSHOT)
19:31:02 [INFO] Recipes: 307 shaped, 63 shapeless, 26 furnace, 10 dynamic, 44 fuels.
19:31:02 [WARNING] The server is running in offline mode! Only do this if you know what you''re doing.
19:31:02 [INFO] Scanning plugins...
19:31:02 [SEVERE] Error during server startup.
java.lang.IllegalArgumentException
        at org.objectweb.asm.ClassReader.<init>(Unknown Source)
        at org.objectweb.asm.ClassReader.<init>(Unknown Source)
        at org.objectweb.asm.ClassReader.<init>(Unknown Source)
        at net.glowstone.GlowPluginTypeDetector.scanFile(GlowPluginTypeDetector.java:94)
        at net.glowstone.GlowPluginTypeDetector.scan(GlowPluginTypeDetector.java:45)
        at net.glowstone.GlowServer.loadPlugins(GlowServer.java:1232)
        at net.glowstone.GlowServer.start(GlowServer.java:772)
        at net.glowstone.GlowServer.run(GlowServer.java:627)
        at net.glowstone.GlowServer.main(GlowServer.java:491)

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[mastercoms]

What are the JAR files in your plugins/ folder?

[Foorack]

This seems to be caused at https://github.com/GlowstoneMC/Glowstone/blob/a5bc22f6212eb3b81dfe529758f6cd80203fb565/src/main/java/net/glowstone/GlowPluginTypeDetector.java#L94

Would it be possible to change https://github.com/GlowstoneMC/Glowstone/blob/a5bc22f6212eb3b81dfe529758f6cd80203fb565/src/main/java/net/glowstone/GlowPluginTypeDetector.java#L112 from IOException to Exception to catch this as well? It would be very helpful if it printed what file is causing the error.

Plugins folder on dev server:

[aramperes]

What Java version are you using? And can you try removing plugins 1 by 1 until it works?

[Foorack]

@momothereal

minecraft@ck1:~/dev$ java -version
openjdk version "9.0.4"
OpenJDK Runtime Environment (build 9.0.4+12-Ubuntu-116.04.york0)
OpenJDK 64-Bit Server VM (build 9.0.4+12-Ubuntu-116.04.york0, mixed mode)

I made the change mentioned in my previous post and it seems like 4 out of 5 of our custom plugins is causing that error. All plugins are compiled normally with maven and java 9.

[Foorack]

This seems to be because of an outdated version of ASM. We compile all our plugins towards Java 9. It is hardcoded to simply crash at anything newer than Java 8. Would it be possible to upgrade to a newer version of ASM?

https://gitlab.ow2.org/asm/asm/blob/ASM_5_0_4/src/org/objectweb/asm/ClassReader.java#L170

[Foorack]

ASM dependency is coming from GlowKit. It is currently using asm-all:5.0.4. Support for Java 9 and 10 was released in ASM 6. I managed to get it working by excluding asm-all and adding asm:6.1.1 and ask-commons:6.1.1. I created a merge request.

[Jannyboy11]

I had the same issue today on Glowstone 2018.0.1 (downloaded the LTS version from your website today), running on Java 13, trying to load a plugin compiled with --release 11

[mastercoms]

The LTS version will not have these changes that fixes this issue.

[Jannyboy11]

It's not really long-term support then, is it? Which version should I be using instead? I tried with version 2018.9.0 and the 'latest build', both also downloaded from https://glowstone.net/#downloads, but both have the same issue.

[mastercoms]

No, we currently don't have the development time to maintain the LTS branch, so its been paused. Did you try this one? https://repo.glowstone.net/repository/snapshots/net/glowstone/glowstone/2018.10.0-SNAPSHOT/glowstone-2018.10.0-20200302.035422-5.jar

[Jannyboy11]

Yes, still the same issue.

C:\Users\Test\Minecraft\Servers\Glowstone-1.12.2>java -jar glowstone-2018.10.0-20200302.035422-5.jar
22:36:32 [INFO] This server is running Glowstone version 2018.10.0-SNAPSHOT.83df5ad (MC: 1.12.2) (Implementing API version 1.12.2-R6.0-SNAPSHOT)
22:36:33 [INFO] Recipes: 307 shaped, 63 shapeless, 26 furnace, 10 dynamic, 44 fuels.
>
22:36:33 [INFO] Scanning plugins...
22:36:33 [SEVERE] Error during server startup.
java.lang.IllegalArgumentException: Unsupported class file major version 55
        at org.objectweb.asm.ClassReader.<init>(ClassReader.java:166)
        at org.objectweb.asm.ClassReader.<init>(ClassReader.java:148)
        at org.objectweb.asm.ClassReader.<init>(ClassReader.java:136)
        at org.objectweb.asm.ClassReader.<init>(ClassReader.java:237)
        at net.glowstone.GlowPluginTypeDetector.scanFile(GlowPluginTypeDetector.java:94)
        at net.glowstone.GlowPluginTypeDetector.scan(GlowPluginTypeDetector.java:45)
        at net.glowstone.GlowServer.loadPlugins(GlowServer.java:1239)
        at net.glowstone.GlowServer.start(GlowServer.java:770)
        at net.glowstone.GlowServer.run(GlowServer.java:625)
        at net.glowstone.GlowServer.main(GlowServer.java:489)
>
C:\Users\Test\Minecraft\Servers\Glowstone-1.12.2>

[mastercoms]

Seems like we will have to update ASM again for Java 11.

[Jannyboy11]

Alright, thanks a lot! While you're at it, can I just remind you friendly that updating the dependency version is not enough, you also need to update the asm api version for ClassVisitors to Opcodes.ASM7. I experienced this issue on Spigot when Java 11 was released: https://hub.spigotmc.org/jira/browse/SPIGOT-4398

[VaiTon]

@mastercoms could we change the issue title to something more descriptive? Like "ASM library needs update for every JDK release"