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More importantly, you will learn how to bring all of this knowledge together to demonstrate runtime polymorphism using sound.

This program requires access to the following classes:

  • AudioGraphSinusoidal
  • AudioGraphSquareWave
  • FMSweep
  • MusicComposer08
  • SquareWave
  • StereoPingpong
  • ToneMono
  • TonesStereo
  • WhiteNoise
  • AudioFormatParameters01
  • AudioPlayOrFile01
  • AudioSignalGenerator02

You will find source code for all of these classes in Listing 5 through Listing 16 .

You are already familiar with some of these classes because they were used in earlier modules.

The driver class for this program is the class named MusicComposer08 . That is the only one of the twelve classes that I will discuss in detail. I willleave it as an exercise for the students at this point to study and understand the remaining eleven classes.

Discussion and sample code

The class named MusicComposer08

The purpose of this program is to demonstrate late binding and runtime polymorphism . This is accomplished by using an array of the abstract type AudioSignalGenerator02 populated with references to objects of the following eight classes :

  • AudioGraphSinusoidal
  • AudioGraphSquareWave
  • FMSweep
  • SquareWave
  • StereoPingpong
  • ToneMono
  • TonesStereo
  • WhiteNoise

Each of the classes listed above extends the abstract class named AudioSignalGenerator02 and overrides the inherited abstract method named getMelody .

After the array is populated, a random number generator is used to get a random index into the array. The getMelody method is called on the reference pointed to by the random index. This causes the sound created by that particular audioobject to be played or filed.

This is an example of late binding and runtime polymorphism because the compiler cannot possibly know the value of the random index when the programis compiled.

As in previous modules, the sound can be played immediately or can be saved in an audio file of type AU for playback later. You should be able to play the audio file with anystandard media player that can handle the AU file type.

The program also requires access to the following classes:

  • AudioFormatParameters01
  • AudioPlayOrFile01
  • AudioSignalGenerator02

Beginning of the class named MusicComposer08

Listing 1 shows the beginning of the class named MusicComposer08 . The code in Listing 1 is essentially the same as code that I have explained in several previous modules. Therefore, no further discussion of the code in Listing 1 will be provided in this module.

Listing 1 . Beginning of the class named MusicComposer08.
import java.util.Random; public class MusicComposer08{//Instantiate an object containing audio format parameters with predefined // values. They may be modified by the signal generator at runtime. Values// allowed by Java SDK 1.4.1 are shown in comments in the class definition. AudioFormatParameters01 audioParams = new AudioFormatParameters01();//A buffer to hold the audio data that will be played or filed.byte[] melody;//A place to store the incoming args array. String[]args; //-------------------------------------------------------------------------////Command-line parameter (only one parameter is needed) //If "play", the sound will be played immediately. Otherwise, the string will// be used as a filename for an audio file of type AU. In the latter case, // it must be a string that would be valid as a file name for the operating// system in use. public static void main(String[]args){ //Instantiate a new object of this class.new MusicComposer08(args); }//end main//-------------------------------------------------------------------------//public MusicComposer08(String[] args){//constructor//Save the args array. this.args = args;//Create default args data if no args data is provided on the command line.if(args.length == 0){ this.args = new String[1]; this.args[0]= "play";//Play the melody immediately }//end if

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
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Source:  OpenStax, Accessible objected-oriented programming concepts for blind students using java. OpenStax CNX. Sep 01, 2014 Download for free at https://legacy.cnx.org/content/col11349/1.17
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