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java.lang.NoClassDefFoundError [message #1857273] Fri, 27 January 2023 09:45 Go to next message
Eclipse UserFriend
Hi everyone

I am stuck on the following issue. I took the org.eclipse.ltk.ui.refactoring plugin from the plugins of my eclipse and add the following line.
DebugPlugin debugPlugin = DebugPlugin.getDefault();
The DebugPlugin is located in org.eclipse.debug.core so I add this jar to MANIFEST.MF under Require-Bundle: in the last line add.
org.eclipse.debug.core;bundle-version="3.18.300"

When I run eclipse from my eclipse plugin everything works fine. I export my org.eclipse.ltk.ui.refactoring_3.12.0.v20210618-1953.jar and then replace it in my plugins list. When I start eclipse as soon as I try to use my code NoClassDefFoundError immediately throws.

I made a small test project using a class from another jar. I get the same error, but when I set the classpath everything works. I tried to set classpath for eclipse plugins, but it doesn't help.

Thanks in advance for any ideas or help.
Re: java.lang.NoClassDefFoundError [message #1857287 is a reply to message #1857273] Sat, 28 January 2023 03:01 Go to previous messageGo to next message
Eclipse UserFriend
It's not entirely clear what you mean by "then replace it in my plugins list". Where is this "list" and how are you replacing something?
Re: java.lang.NoClassDefFoundError [message #1857308 is a reply to message #1857287] Mon, 30 January 2023 01:42 Go to previous messageGo to next message
Eclipse UserFriend
Ed Merks wrote on Sat, 28 January 2023 08:01
It's not entirely clear what you mean by "then replace it in my plugins list". Where is this "list" and how are you replacing something?

Hi, Ed thank you for your response.
In my installed IDE I have the folder IDE/eclipse/plugins/
in which I have a lot of plugins / jars
org.eclipse.tools.****<version>.jar
......<>
org.eclipse.ui.****<version>.jar
........<>
totally more 300+ jar files. When I export my jar file which was taken from one of them as a source and slightly changed in my case only one line. After that, I replaced it in the folder with jars. And when I reach that line during runtime it throws the exception NoClassDefFoundError.
Re: java.lang.NoClassDefFoundError [message #1857311 is a reply to message #1857308] Mon, 30 January 2023 02:17 Go to previous messageGo to next message
Eclipse UserFriend
Maybe if you try launching with -clean that will help.

https://help.eclipse.org/latest/index.jsp?topic=%2Forg.eclipse.platform.doc.isv%2Freference%2Fmisc%2Fruntime-options.html

In any case, that's not really a good.proper way to "install" something. Running with -debug might provide more details. You're sure that the given version or higher of org.eclipse.debug.core is in the installation.

I'm not sure that dropins will work either:

https://help.eclipse.org/latest/index.jsp?topic=%2Forg.eclipse.platform.doc.isv%2Freference%2Fmisc%2Fruntime-options.html
Re: java.lang.NoClassDefFoundError [message #1857323 is a reply to message #1857311] Mon, 30 January 2023 07:30 Go to previous message
Eclipse UserFriend
Thank you Ed. It WORKS!!! That was very important for me.
The -clean helped me. I should run my project -clean. In this case, the plugins are recompiled and everything works.

[Updated on: Mon, 30 January 2023 07:31] by Moderator

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