//  ObjectClassTests.java  Copyright (c) 2005 Kari Laitinen

//  http://www.naturalprogramming.com

//  2005-05-17   File created.
//  2005-05-17   Last modification.

//  Testing the ultimate superclass Object.

import java.util.* ;

class  TestClass  implements Cloneable
{
   static int  object_counter  =  0 ;

   int object_number ;

   public TestClass()
   {
      object_counter  ++  ;
      object_number  =  object_counter ;
   }

   public void make_speak()
   {
      System.out.print( "\n Hi! I'm object number "  +  object_number ) ;
   }

   public TestClass clone() throws CloneNotSupportedException
   {
      return ( (TestClass) super.clone() ) ;
   }

   public void finalize()
   {
      System.out.print( "\n Object number " + object_number 
                     +  " is being killed!" ) ;
   }

/***
   public String toString()
   {
      return  "TestClass object number "  +  object_number ;
   }

****/

}

class ObjectClassTests
{

   public static void main( String[] not_in_use )
                              throws CloneNotSupportedException,
                                     InterruptedException
   {
      Scanner  keyboard  =  new Scanner( System.in ) ;

      Integer  some_integer_object  =  333444 ;

      String  some_string  =  "AAABBB" ;

      TestClass  some_test_object  =  new  TestClass() ;

      System.out.print( "\n some_integer_object.hashCode()    "
                  +  some_integer_object.hashCode()
                  +  "\n some_integer_object.getClass()       "
                  +  some_integer_object.getClass() +  "\n" ) ;

      System.out.print( "\n some_string.hashCode()    "
                  +  some_string.hashCode()
                  +  "\n some_string.getClass()       "
                  +  some_string.getClass()  +  "\n" ) ;

      System.out.print( "\n some_test_object.hashCode()    "
                  +  some_test_object.hashCode()
                  +  "\n some_test_object.getClass()       "
                  +  some_test_object.getClass() 
                  +  "\n some_test_object.toString()       "
                  +  some_test_object    +  "\n" ) ;

      Object  some_object  =  some_test_object ;

      System.out.print( "\n some_object.getClass()    "
                     +  some_object.getClass() 
                     +  "\n" ) ;

      some_object  =  some_integer_object ;

      System.out.print( "\n some_object.getClass()    "
                     +  some_object.getClass() 
                     +  "\n" ) ;

      some_object  =  some_string ;

      System.out.print( "\n some_object.getClass()    "
                     +  some_object.getClass() 
                     +  "\n" ) ;

      TestClass  another_test_object  =  new TestClass() ;

      some_test_object.make_speak() ;
      another_test_object.make_speak() ;

      TestClass  third_test_object  =  some_test_object.clone() ;
      third_test_object.make_speak() ;

      // Let's make the three objects non-referenced objects (i.e. garbage)

      third_test_object  =  null ;
      another_test_object  =  null ;
      some_test_object  =  null ;

      System.gc() ; // Let's force garbage collector to do its job.  

      // Let's wait that the garbage collector does its job.

      System.out.print( "\n Press the Enter key to continue ... " ) ;
      String any_string_from_keyboard  =  keyboard.nextLine() ;
   }
}