Glowstone/Guava 10 compatibility (vs Guava 17)

[deathcap]

Glowstone (tested on build 123) currently bundles Guava version 10 (see https://github.com/GlowstoneMC/Glowkit/pull/68 Update to Guava 17), but SpongeAPI requires Guava 17, therefore Bukkit2Sponge uses it (and relocating to avoid version conflicts breaks interface contracts, see #3), failing to load due to this version difference:

18:11:08 [SEVERE] Error occurred while enabling Bukkit2Sponge v0.5 (Is it up to date?)
java.lang.NoSuchMethodError: com.google.common.cache.CacheBuilder.build()Lcom/google/common/cache/Cache;
at com.google.inject.internal.WeakKeySet.(WeakKeySet.java:55)
at com.google.inject.internal.InheritingState.(InheritingState.java:65)
at com.google.inject.internal.InjectorShell$Builder.getState(InjectorShell.java:203)
at com.google.inject.internal.InjectorShell$Builder.lock(InjectorShell.java:114)
at com.google.inject.internal.InternalInjectorCreator.build(InternalInjectorCreator.java:103)
at com.google.inject.Guice.createInjector(Guice.java:96)
at com.google.inject.Guice.createInjector(Guice.java:73)
at com.google.inject.Guice.createInjector(Guice.java:62)
at io.github.deathcap.bukkit2sponge.Bukkit2Sponge.load(Bukkit2Sponge.java:54)
at io.github.deathcap.bukkit2sponge.Bukkit2Sponge.onEnable(Bukkit2Sponge.java:47)
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:316)
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:324)
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:404)
at net.glowstone.GlowServer.enablePlugins(GlowServer.java:726)
at net.glowstone.GlowServer.start(GlowServer.java:477)
at net.glowstone.GlowServer.main(GlowServer.java:106)

Bukkit2Sponge unfortunately can't downgrade to Guava 10 since SpongeAPI needs Guava 17. Maybe this conflict can be solved by dynamically relocating Guava in the plugin classloader (in addition to maven-shade-plugin relocation at build time).

[jamierocks]

We modify Bukkit like https://github.com/CanaryBukkitTeam/BukkitC for CanaryBukkit. You could do the same for SpongeAPI?

[phase]

@jamierocks It'd be better to use "vanilla" Sponge, so it's compatible with everything. It might be possible to make small changes.

[deathcap]

Yeah I'd like to use SpongeAPI unmodified if at all possible, easier than maintaining a fork, and the SpongePowered team seems open to changes if there's anything reasonable that would need to be changed there.

But changing SpongeAPI to use Guava 10 is, sadly, not feasible - not only would that be a downgrade, but would also break Guava 17 compatibility with plugins. As I understand it, they have to stick to 17 because that's what Minecraft uses (notwithstanding bundling their own relocated version).

On the Bukkit API side, fixed this in Glowstone++ by using a Glowkit/Bukkit updated with Guava 17 (via Spigot-Bukkit), so its now only a problem on the original Glowstone, and potentially older Bukkit server implementations. When did Spigot update Bukkit to use Guava 17, I think it was Minecraft 1.8? or 1.7? Maybe worth just dropping older version support..

[deathcap]

A possible reason to support Guava 10 in older servers:

https://forums.spongepowered.org/t/bukkit2sponge-an-implementation-of-spongeapi-for-bukkit-servers/6747/22

nice smile but my moded servers are still in 1.6.4 so no chance to use it frowning

[jamierocks]

Why not just use Spigot's version of bukkit?

[deathcap]

@jamierocks https://forums.glowstone.net/t/spigots-new-1-8-bukkit-api/68/25

PR #10 adds class relocation so the Guava is independent from whatever the server platform bundles. With this change Bukkit2Sponge loads on Glowstone (and still loads on Glowstone++), and should also work on other servers using Bukkit 1.7.10-derived/earlier APIs (untested).