Question

(JAVA NetBeans)

Write programs in java

Example 10.21-24

//Animal.java

/**  Animal class
*    Anderson. Franceschi
*/

import java.awt.Graphics;

public abstract class Animal
{
  private int x;      // x position
  private int y;      // y position
  private String ID;  // animal ID

  /** default constructor
  *    Sets ID to empty String
  */
  public Animal( )
  {
    ID = "";
  }

  /** Constructor
  *    @param rID   Animal ID
  *    @param rX    x position
  *    @param rY    y position
  */
  public Animal( String rID, int rX, int rY )
  {
    ID = rID;
    x = rX;
    y = rY;
  }

  /** accessor for ID
  *   @return  ID
  */
  public String getID( )
  {
    return ID;
  }

  /** accessor for x
  *   @return  x coordinate
  */
  public int getX( )
  {
    return x;
  }

  /** accessor for y
  *   @return  y coordinate
  */
  public int getY( )
  {
    return y;
  }

  /** mutator for x
  *   @param  newX  new value for x position
  */
  public void setX( int newX )
  {
    x = newX;
  }

  /** mutator for y
  *   @param  newY  new value for y position
  */
  public void setY( int newY )
  {
    y = newY;
  }

  /** abstract method for drawing Animal
  *   @param   g    Graphics context
  */
  public abstract void draw( Graphics g );
}

======================================================================================

//Moveable.java

/** Moveable interface
*   Anderson, Franceschi
*/

public interface Moveable
{
  int FAST = 5; // static constant
  int SLOW = 1; // static constant

  void move( ); // abstract method
}

======================================================================================

//Pause.java

/* Pause class to pause applications
   Anderson, Franceschi
*/

public class Pause
{
  public static void wait( double time )
  {
     try {
      Thread.sleep(  ( int ) ( time * 1000 ) );
     }
     catch ( InterruptedException e )
     {
      e.printStackTrace();
     }
  }
}

======================================================================================

//TortoiseRacer.java

/**  TortoiseRacer class
*    inherits from abstract Animal class
*    implements Moveable interface
*    Anderson, Franceschi
*/

import java.awt.Graphics;
import java.awt.Color;

public class TortoiseRacer extends Animal implements Moveable
{
   /** Default Constructor: calls Animal default constructor
   */
   public TortoiseRacer( )
   {
     super( );
   }

   /** Constructor
   *    @param rID  racer Id, passed to Animal constructor
   *    @param rX   x position, passed to Animal constructor
   *    @param rY   y position, passed to Animal constructor
   */
   public TortoiseRacer( String rID, int rX, int rY )
   {
     super( rID, rX, rY );
   }

   /** draw: draws the Tortoise at current (x, y) coordinate
   *       implements abstract method in Animal class
   *       @param g   Graphics context
   */
   public void draw( Graphics g )
   {
     int startX = getX( );
     int startY = getY( );

     g.setColor( new Color( 34, 139, 34 ) ); // dark green

     //body
     g.fillOval( startX, startY, 25, 15 );

     //head
     g.fillOval( startX + 20, startY + 5,  15, 10 );

     //flatten bottom
      g.clearRect( startX, startY + 11, 35, 4 );

     //feet
     g.setColor( new Color( 34, 139, 34 ) );  // brown
     g.fillOval( startX + 3, startY + 10,  5, 5 );
     g.fillOval( startX + 17, startY + 10, 5, 5 );
   }

    /** implements move method in Moveable interface
    *   move:  calculates the new x value for the racer
    *   Tortoise move characteristics: "slow & steady wins the race"
    *      increment x by SLOW (inherited from Moveable interface)
    */
    public void move( )
    {
        setX( getX( ) + SLOW );
    }
}

======================================================================================

//TortoiseRacerClient.java

/* A Graphical Application 
   TortoiseRacer Client
   Anderson, Franceschi
   mchang 20190307
*/

import javax.swing.JFrame;
import java.awt.Graphics;

public class TortoiseRacerClient extends JFrame
{
  private TortoiseRacer t;

  public TortoiseRacerClient( )
  {
    t = new TortoiseRacer( "Tortoise", 50, 50 );
  }

  public void paint( Graphics g )
  {
    super.paint( g );
    for ( int i = 0; i < getWidth( ); i++ )
    {
      t.move( );
      t.draw( g );
      Pause.wait( .03 );
      g.clearRect( 0, 0, getWidth( ), getHeight( ) );
    } 
  }
  
  public static void main( String [] args )
  {
    TortoiseRacerClient app = new TortoiseRacerClient( );
    app.setSize( 400, 300 );
    app.setVisible( true );
  }
}

3. Modify example 10.21-24 to have a number of tortoiseRacer objects moving with a different speed.. t

Answer 1

Following are the things I have changed in the code.

1. I have changed the speed, added one more speed and changed the move function to get the variation of the speed.
2. I have added two more tortoise objects which move at different speeds added.

Following is the updated code of all the files, Changed code would be marked in the bold.

//Animal.java

/** Animal class
* Anderson. Franceschi
*/

import java.awt.Graphics;

public abstract class Animal
{
private int x; // x position
private int y; // y position
private String ID; // animal ID

/** default constructor
* Sets ID to empty String
*/
public Animal( )
{
ID = "";
}

/** Constructor
* @param rID Animal ID
* @param rX x position
* @param rY y position
*/
public Animal( String rID, int rX, int rY )
{
ID = rID;
x = rX;
y = rY;
}

/** accessor for ID
* @return ID
*/
public String getID( )
{
return ID;
}

/** accessor for x
* @return x coordinate
*/
public int getX( )
{
return x;
}

/** accessor for y
* @return y coordinate
*/
public int getY( )
{
return y;
}

/** mutator for x
* @param newX new value for x position
*/
public void setX( int newX )
{
x = newX;
}

/** mutator for y
* @param newY new value for y position
*/
public void setY( int newY )
{
y = newY;
}

/** abstract method for drawing Animal
* @param g Graphics context
*/
public abstract void draw( Graphics g );
}

//Moveable.java

/** Moveable interface
* Anderson, Franceschi
*/

public interface Moveable
{
int FAST = 3; // static constant
int SLOW = 1; // static constant
int SUPERFAST = 7; // static constant
void move(int variation); // abstract method
}

//Pause.java

/* Pause class to pause applications
Anderson, Franceschi
*/

public class Pause
{
public static void wait( double time )
{
try {
Thread.sleep( ( int ) ( time * 1000 ) );
}
catch ( InterruptedException e )
{
e.printStackTrace();
}
}
}

//TortoiseRacer.java

/** TortoiseRacer class
* inherits from abstract Animal class
* implements Moveable interface
* Anderson, Franceschi
*/

import java.awt.Graphics;
import java.awt.Color;

public class TortoiseRacer extends Animal implements Moveable
{
/** Default Constructor: calls Animal default constructor
*/
public TortoiseRacer( )
{
super( );
}

/** Constructor
* @param rID racer Id, passed to Animal constructor
* @param rX x position, passed to Animal constructor
* @param rY y position, passed to Animal constructor
*/
public TortoiseRacer( String rID, int rX, int rY )
{
super( rID, rX, rY );
}

/** draw: draws the Tortoise at current (x, y) coordinate
* implements abstract method in Animal class
* @param g Graphics context
*/
public void draw( Graphics g )
{
int startX = getX( );
int startY = getY( );

g.setColor( new Color( 34, 139, 34 ) ); // dark green

//body
g.fillOval( startX, startY, 25, 15 );

//head
g.fillOval( startX + 20, startY + 5, 15, 10 );

//flatten bottom
g.clearRect( startX, startY + 11, 35, 4 );

//feet
g.setColor( new Color( 34, 139, 34 ) ); // brown
g.fillOval( startX + 3, startY + 10, 5, 5 );
g.fillOval( startX + 17, startY + 10, 5, 5 );
}

/** implements move method in Moveable interface
* move: calculates the new x value for the racer
* Tortoise move characteristics: "slow & steady wins the race"
* increment x by SLOW (inherited from Moveable interface)
*/
public void move(int variation)
{
   switch(variation){
   case 1: {
       setX( getX() + SLOW );break;
   }
   case 2: {
       setX( getX() + FAST );break;
   }
   case 3:{
       setX( getX() + SUPERFAST );break;
   }
   default:
       break;
   }
  
}

}

/* A Graphical Application
TortoiseRacer Client
Anderson, Franceschi
mchang 20190307
*/

import javax.swing.JFrame;
import java.awt.Graphics;

public class TortoiseRacerClient extends JFrame
{
private TortoiseRacer t;
private TortoiseRacer t1_new;
private TortoiseRacer t2_new;
public TortoiseRacerClient( )
{
t = new TortoiseRacer( "Tortoise", 50, 50 );
t1_new = new TortoiseRacer("Tortoise_new1", 50, 100);
t2_new = new TortoiseRacer("Tortoise_new2", 50, 200);
}

public void paint( Graphics g )
{
super.paint( g );
for ( int i = 0; i < getWidth(); i++ )
{
// 1 --> for slow
// 2 --> for fast
// 3 --> for super-fast
t.move(1);
t.draw( g );  

t1_new.move(2);
t1_new.draw( g );  

t2_new.move(3);
t2_new.draw( g );

Pause.wait( .03 );
g.clearRect( 0, 0, getWidth(), getHeight() );
}
}

public static void main( String [] args )
{
TortoiseRacerClient app = new TortoiseRacerClient( );
app.setSize( 400, 300 );
app.setVisible( true );
}
}

I have tested it, I cannot put the snippet of animation here. But I have tested it thoroughly.

I have tested the code properly. If you would have any doubt please comment.
Thanks