This error is just bizarre, my code compiles fine, I can see there are no problems with it, yet this error has just popped up. I have tried re-starting netbeans and there is no additional exception information.
What can cause this?
I guess you are using an IDE (like Netbeans) which allows you to run the code even if certain classes are not compilable. During the application's runtime, if you access this class it would lead to this exception.
If it is Netbeans, try to uncheck "Compile on save" setting in the project properties (Build -> Compiling). This is the only thing which helped me in a similar situation.
Even though this question is old , I want to note this answer for NETBEANS users :
delete everything in
.netbeans/6.9/var/cache/index/. change 6.9 with your version.
Disable Deploy on Save in the Project's Properties/Run screen. That's what worked for me finally. Why the hell NetBeans screws this up is beyond me.
Note: I was able to compile the file it was complaining about using right-click in NetBeans. Apparently it wasn't really compiling it when I used Build & Compile since that gave no errors at all. But then after that, the errors just moved to another java class file. I couldn't compile then since it was grayed out. I also tried deleting the build and dist directories in my NetBeans project files but that didn't help either.
very late reply. I also got the same error and I did clean build and it worked.
Organize your code as a maven module. Once done run the command from terminal
to check if your code builds fine.
Finally import the project in netbeans or eclipse as maven project.
Did you try compiling it using the command line?
you'll have to use the command "javac" for that
change the package of classes, your files are probably in the wrong package, happened to me when I copied the code from a friend, it was the default package and mine was another, hence the netbeans could not compile because of it.
I had this problem with NetBeans 8.0.1. Messages about problem in project deleted class. Deleting the ~/.netbeans didn't work. Also I looked for ANY reference to the deleted class in ALL my projects, nothing found. I deleted the build classes, everything. Then, when I started Netbeans again, compile and magically appears the message in Run and into the mother compiled class. I tried the uncheck "Compile on save" Dime solution, and works, but it's not practical. Finally, my solution was edit and force recompile of the mother class. This way the new .class doesn't contains the message and Run works OK.
Just check the packaging, the simplest answer I can provide is that your package has been mislabeled (within a class).
Also, you may have some weird characters. Try white-flushing the code in a Notepad (or Gedit) and then pasting it into a newly created class with your IDE.