Java Learning Essay exception a class file is not written.

Write a program today, an exception occurred

Java.lang.NoClassDefFoundError

Then the error message is

A class file is not written. The project is inconsistent, if so try refreshing this project and building it

Internet search, there is said I workspace full, but not ah, my computer although slag, this memory may still have AH. The final answer is funny:

Here are some other reserved words that cannot be created under Windows. Pay attention, don't divide the case. Con,con,con can not!

Con is a device name reserved by the operating system, and there are many device names that cannot be used, as follows:

The following reserved device names cannot be used as the name of a File:con, PRN, AUX, clock$, NUL, COM1, COM2, COM3, CO M4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9. Also avoid these names followed by a extension (for example, nul.tx7).

Java Learning Essay exception a class file is not written.