package test;

public class Test {
  public static void main(String[] args) {
    String msg = "";
    if ( args.length > 0) msg = args[0];
    test.outer.Lib.say(msg);
  }

  static { System.out.println("Start loading " + Test.class.toString() + " ..."); }
}

package test.outer;

public class Lib {
  public static void say(String msg) { Outer.say(msg); }

  static { System.out.println("Start loading " + Lib.class.toString() + " ..."); }
}

class Outer {
  static void say(String msg) { System.err.println(msg); }

  static { System.out.println("Start loading " + Outer.class.toString() + " ..."); }
}

  rd/q/s bin&md bin
  javac -d bin -cp bin src/Test.java
  src\Test.java:7: error: package test.outer does not exist
      test.outer.Lib.say(msg);
              ^
  1 error

  javac -d bin src/Lib.java&del bin\test\outer\outer.class
  javac -d bin -cp bin src/Test.java
  java -cp bin test.Test Hello?
  Start loading class test.Test ...
  Start loading class test.outer.Lib ...
  Exception in thread "main" java.lang.NoClassDefFoundError: test/outer/Outer
          at test.outer.Lib.say(Lib.java:4)
          at test.Test.main(Test.java:7)
  Caused by: java.lang.ClassNotFoundException: test.outer.Outer
          at java.net.URLClassLoader.findClass(Unknown Source)
          at java.lang.ClassLoader.loadClass(Unknown Source)
          at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
          at java.lang.ClassLoader.loadClass(Unknown Source)
          ... 2 more

  java -d bin -cp bin src/Lib.java
  java -cp bin test.Test Hello?
  Start loading class test.Test ...
  Start loading class test.outer.Lib ...
  Start loading class test.outer.Outer ...
  Hello?