[1.7.10] NoClassDefFoundError When Using External Library

nalexander50 · January 9, 2015

I am working on my first, small mod, and I am attempting to use an external jar. The jar is jeval found at http://jeval.sourceforge.net. I placed the jar file in my mod's libs folder, added the jar to my IDEA project with "Export" checked and set to "Compile." Everything works inside the development environment. I can fire up Minecraft from IDEA and everything works flawlessly. However, when I try to real Minecraft with my mod installed, I get a whole slew of ClassDefNotFoundError relating to my external library. If I add BOTH my mod jar AND the external jar to the mods folder, everything works; however, this is not really an ideal solution. I believe everything should get packed into my mod jar. I also had the idea of just packing both jars into a zip and placing in the mods folder which didn't work (as I had expected). I have Google'd and YouTube'd for hours and tried many different solutions to no avail. I appreciate any help - let me know if you need more information!

The relevant stacktrace:

[03:43:10] [server thread/ERROR] [FML]: Fatal errors were detected during the transition from SERVER_ABOUT_TO_START to SERVER_STARTING. Loading cannot continue

[03:43:10] [server thread/ERROR] [FML]:

mcp{9.05} [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available

FML{7.10.85.1277} [Forge Mod Loader] (forge-1.7.10-10.13.2.1277-universal.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available

Forge{10.13.2.1277} [Minecraft Forge] (forge-1.7.10-10.13.2.1277-universal.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available

chatcalc{1.7.10-0.1} [ChatCalc] (chatcalc-1.0.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Errored

[03:43:10] [server thread/ERROR] [FML]: The following problems were captured during this phase

[03:43:10] [server thread/ERROR] [FML]: Caught exception from chatcalc

java.lang.NoClassDefFoundError: net/sourceforge/jeval/EvaluationException

at main.java.com.alexander.chatcalc.ChatCalc.serverStart(ChatCalc.java:35) ~[ChatCalc.class:?]

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_25]

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_25]

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_25]

at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_25]

at cpw.mods.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:513) ~[forge-1.7.10-10.13.2.1277-universal.jar:?]

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_25]

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_25]

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_25]

at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_25]

at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) ~[guava-16.0.jar:?]

at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) ~[guava-16.0.jar:?]

at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) ~[guava-16.0.jar:?]

at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) ~[guava-16.0.jar:?]

at com.google.common.eventbus.EventBus.post(EventBus.java:275) ~[guava-16.0.jar:?]

at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:208) ~[forge-1.7.10-10.13.2.1277-universal.jar:?]

at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:187) ~[forge-1.7.10-10.13.2.1277-universal.jar:?]