NoClassDefinationFound Explained !!

The above Exception occurs when the intended class is not found in the Class Path.
At Compile Time Class : Class was generated from Java Compiler, But Somehow
at Run Time the Dependent Class is not found.

Lets go through one Simple Example :

public class ClassA{
    public static void main(String args[]){
         //Some gibberish Code...
         String text = ClassB.getString();
         System.out.println("Text is :" + text);
    }
}

public class ClassB{

  public static String getString(){
         return "Testing Some Exception";
     }
}


Now Lets assume that the above two Java Source Code are placed in some Folder let say "NoClassDefinationFoundExceptionDemo"

Now open a shell(Assuming Java is already being setup correctly)
1)Go to Folder "NoClassDefinationFoundExceptionDemo"
2)Compile Java Source Files
     javac ClassB
     javac ClassA
3)Both Files are Compiled Sucessfully and generated Class files in the same Folder
   as ClassA.class and ClassB.class
4)Now Since we are overiding ClassPath to current working directory
    therefore we execute the following command
    java -cp . ClassA
    and It worked Successfully and you will see the Output in the screen
5)Now Lets say, You removed  ClassB.class file from Present Directory.
   and now you execute the command again.
   java -cp . ClassA
  Now it will greet you with NoClassDefFoundException. as ClassB which is a dependency
  for ClassA is not found in the classpath(i.e present working directory).