Package NOT accessible outside parent/root directory - NoClassDefFoundError

Question

I can't seem to import a package I created, EXCEPT UNDER THE TOP LEVEL
PARENT DIRECTORY. The following chronicles what I attempted. I read, and
tried related postings in this newsgroup, but they have not totally
solved my problems.
/* d:\java\zsamples\zswingpackage1\swing-optgrp-eg1.java
/* Following package stmts. causing run-time error "Exception in thread
"main" java.lang.NoClassDefFoundError: zswingpackage1/Swing
OptGroup1a [(wrong name: java/zsamples/zswingpackage1/SwingOptGroup1a)]".
Solution: as suggested in newsgroup posting, changed package stmt. to
include ONLY the SUBDIRECTORIES UNDERNEATH the top level 'java'
directory (EXCLUDE 'java.' qualifier from package stmt.). Compiled from
the parent directory of the package path, and also ran from that path
i.e.
package zsamples.zswingpackage1;     // omits the top level 'java' directory
public class swing_optgrp_eg1 extends JFrame {
Here's how I compiled:
     cd java
     d:\java>javac zsamples\zswingpackage1\swing_optgrp_eg1.java
Here's how I executed:
     Following WORKED. Uses '.' aot backslash qualifier.
     D:\java>java zsamples.zswingpackage1.swing_optgrp_eg1
     Above package defn. solution allowed a calling program (residing under
     the top level 'java' directory) to successfully import the package
     (refer \java\test-package2.java)!! But having difficulties in importing
     this package when referenced in a calling program RESIDING IN A DEEPER
     LEVEL DIRECTORY, such as d:\java\zsamples (refer package-test1.java).
Calling program1 (resides under d:\java\package-test2.java): WORKED
     /* This source purposely placed in the 1st level directory to test the
     theory/scenario: is it necessary to store the calling program (that
     accesses my package) in the top level directory (d:\java)? */
     import zsamples.zswingpackage1.swing_optgrp_eg1;     // resides under d:\java
Calling program2 (resides under d:\java\zsamples\package-test1.java): DID NOT WORK
     /* Following import causing "package zsamples.zswingpackage1 does not exist"
          COMPILE ERROR. But worked in package-test2.java.
     Solution (wasn't necessary in package-test2.java):
          - specified 'java' in classpath i.e.          
               d:\java\zsamples>javac package-test1.java -classpath .;d:\java
          But subsequently, when RUNNING using D:\java\zsamples>java Package_Test1,
          caused RUN-TIME error "Exception in thread "main" java.lang.NoClassDefFoundError:
          zsamples/zswingpackag e1/swing_optgrp_eg1".
          import zsamples.zswingpackage1.swing_optgrp_eg1;     // resides under d:\java
     /* Unsuccessful remedies:
     1) use -classpath with compiler i.e.
          d:\java\zsamples>javac package-test1.java -classpath .;d:\java\zsamples\zswingpackage1
     2) removed top level 'zsamples' qualifier in package name, compiled
          with, and without -classpath parm. i.e.
          import zswingpackage1.swing_optgrp_eg1;     // resides under d:\java\zsamples
          This caused "cannot access zswingpackage1.swing_optgrp_eg1 bad class
          file: .\zswingpackage1\swing_optgrp_eg1.class class file contains wrong
          class: zsamples.zswingpackage1.swing_optgrp_eg1 Please remove or make
          sure it appears in the correct subdirectory of the classpath."
     3) added top level 'java.' qualifier in package name, compiled with, and
          without -classpath parm. i.e.
          import java.zsamples.zswingpackage1.swing_optgrp_eg1;
          This caused "package java.zsamples.zswingpackage1 does not exist".
     4) when running, specified '.;d:\java\zsamples\zswingpackage1', or
          '.;d:\java\zsamples' in -classpath i.e.
               D:\java\zsamples>java Package_Test1 -classpath .;d:\java\zsamples\zswingpackage1
               D:\java\zsamples>java Package_Test1 -classpath .;d:\java\zsamples
     // Following import caused same errors as above import stmt.
     //import zsamples.zswingpackage1.*;
     class Package_Test1 {
My PC configuration:
     java version "1.4.0_01"
     Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0_01-b03)
     Java HotSpot(TM) Client VM (build 1.4.0_01-b03, mixed mode)
     JRun 4 (Build 47304)
     WinNT 4.0 SP5
     IE 5.50
     CLASSPATH=.;D:\jakarta-tomcat-3.3.1\lib\common\servlet.jar;
          C:\JRun4\servers\default\default-ear\default-war\WEB-INF\classes
     JAVA_HOME=C:\j2sdk1.4.0_01
     Path=C:\j2sdk1.4.0_01\bin;C:\WINNT\system32;C:\WINNT;
          C:\Program Files\Network Associates\PGPNT;C:\Program Files\MTS;d:\MSSQL7\BINN

Answer 1

It's hard for me to follow everything you posted. Perhaps this link will help.
http://java.sun.com/docs/books/tutorial/java/interpack/packages.html
Some things to keep in mind. Packages are not directories - they just use the path structure of directories to manage namespaces. No matter where a class is, if your Classpath is d:\java, then the root of any class in a package must be in a directory structure that exists inside d:\java. Also, compilers and the JVM utilize the fully qualified name of a class, meaning the package name plus the class name.