Run a project without source .java files in Eclipse

I have a java proje开发者_开发知识库ct in Eclipse that I am trying to run/debug. When I run the project Eclipse goes into Debug mode and then throws a ClassNotFound Exception. I have a class folder in the default package in my project that contains all the necessary class files. Any help regarding this would be appreciated. Thanks!

The classes folder needs to be added to the project's classpath. Putting classes into the source directory isn't going to work. Go to project properties -> Java Build Path to configure this.