compiling, executing problems after re-structuring program into packages

I've broken my application, because I don't fully understand how to use packages

I've tried to make a test program with the same structure and can't get it to work either.

My question is how to get my test program to work, so I can apply the solution to my broken application.

Here is the test program:

my directory structure is
/main/packageExample/topPackage/subPackage/subSubPackage

topPackage directory contains one file

Top.java

subPackage directory contains one file

Sub.java

subSubPackage directory contains one file

SubSub.java

I want to run Top , which will call Sub, which will call SubSub, where
Top is in package topPackage
Sub is in a subPackage (sub package of topPackage)
and SubSub is in subSubPackage (a sub package of subPackage)

Here is what I came up with for the contents of these 3 files

FILE: Top.java
----------------

package topPackage;
import java.io.*;
import subPackage.*;

public class Top
{
    public static void main(String[] args) throws IOException
    {
       Top top = new Top( );
    }

  public Top( )
  {
    topString = new String("Hello Top");
    sub = new Sub( );
  }
 String topString;
 Sub sub;
 }


FILE: Sub.java
----------------------------

package topPackage.subPackage;
import subSubPackage.*;

public class Sub
{
  public Sub( )
  {
    subString = new String("Hello Sub");
    subSub = new SubSub( );
  }
 String subString;
 SubSub subSub;
}

FILE: SubSub.java
----------------------------

package topPackage.subPackage.subSubPackage;

public class SubSub
{
  public SubSub( )
  {
    subSubString = new String("Hello SubSub");
  }
 String subSubString;
}