Eclipse ClassNotFoundException

Question

Everything works fined, but suddenly eclipse stopped execute and junit tests or even main method, when i run them using run as - > Java application, run as -> junit test

It simply throws error

Caused by: java.lang.ClassNotFoundException: package.ClassName

whene ClassName - is class from where i trying to run method main. It affect only one of my projects ... Different workspaces works fine, other project in same workspace works fine as well.

I'm sure if i recreate current project, error will gone. But the adjustments of this project in eclipse is really hard, so i want to avoid it.

Any clue?

Answer 1

ClassName不在类路径中，如果从控制台启动，则应使用-cp参数，如果从eclipse开始，请将ClassName添加到当前（开始）项目的源代码中。

Answer 2

Ok, I finally figured it out. The problem was with installed JRE in eclipse setting. I was playing around with this setting and changed installed JRE to JDK, and for some reason it broke the eclipse project.

Answer 3

Thanks to adarshr , I was able to look at the Problems window and determine that the build was failing because it could not find a class I had written.

I had used the MS TFS plugin to create a " shelveset " and it was supposed to have removed my pending changes in the process. However, this integration with the TFS snapin and Eclipse is obviously not well implemented, since the Eclipse project still thought the file existed and was complaining that it could not be compiled.

I went and manually deleted those "files" or "non-existing files" from the Eclipse project (that I thought I had removed with the shelveset action) and the problem was solved.

Also....

Another annoying things is that the Tomcat error I was getting by trying to debug within Eclipse was like this:

SEVERE: Error configuring application listener of class com.CompanyName.ProjectName.servlet.StartupConfigListener java.lang.ClassNotFoundException: com.CompanyName.ProjectName.servlet.StartupConfigListener at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1643)

In reality, there was no problem at all with StartupConfigListener.java!! The build failed due to the OTHER problems I mentioned above, and therefore I guess this was the first class it attempted to load and failed.... because the entire project hadn't been able to compile perhaps?

(Here's to hoping my next project is using Visual Studio instead of Eclipse!)

Answer 4

You can also try going back to the basics. Check your command line and VM args. I've had this situation where a VM arg I was passing in was a path to a file that had a space in the path, and I had forgotten to include the full path in quotes. So eg, if my arg looked something like

-DFILE=C:\Documents and Settings\myfile

...I'd get a java.lang.NoClassDefFoundError caused by a java.lang.ClassNotFoundException.