************************
Ship.java A Ship class illustrating object-oriented programming concepts. Incorporates Javadoc comments. See ShipTest.java for a test.
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/** Ship example to demonstrate OOP in Java.
*
* @author
* Larry Brown
* @version 2.0
*/
public class Ship {
// Instance variables
private double x=0.0, y=0.0, speed=1.0, direction=0.0;
private String name;
// Constructors
/** Build a ship with specified parameters. */
public Ship(double x, double y, double speed,
double direction, String name) {
setX(x);
setY(y);
setSpeed(speed);
setDirection(direction);
setName(name);
}
/** Build a ship with default values
* (x=0, y=0, speed=1.0, direction=0.0).
*/
public Ship(String name) {
setName(name);
}
/** Move ship one step at current speed/direction. */
public void move() {
moveInternal(1);
}
/** Move N steps. */
public void move(int steps) {
moveInternal(steps);
}
private void moveInternal(int steps) {
double angle = degreesToRadians(direction);
x = x + (double)steps * speed * Math.cos(angle);
y = y + (double)steps * speed * Math.sin(angle);
}
private double degreesToRadians(double degrees) {
return(degrees * Math.PI / 180.0);
}
/** Report location to standard output. */
public void printLocation() {
System.out.println(getName() + " is at (" + getX() +
"," + getY() + ").");
}
/** Get current X location. */
public double getX() {
return(x);
}
/** Set current X location. */
public void setX(double x) {
this.x = x;
}
/** Get current Y location. */
public double getY() {
return(y);
}
/** Set current Y location. */
public void setY(double y) {
this.y = y;
}
/** Get current speed. */
public double getSpeed() {
return(speed);
}
/** Set current speed. */
public void setSpeed(double speed) {
this.speed = speed;
}
/** Get current heading (0=East, 90=North, 180=West,
* 270=South). I.e., uses standard math angles, not
* nautical system where 0=North, 90=East, etc.
*/
public double getDirection() {
return(direction);
}
/** Set current direction (0=East, 90=North, 180=West,
* 270=South). I.e., uses standard math angles,not
* nautical system where 0=North,90=East, etc.
*/
public void setDirection(double direction) {
this.direction = direction;
}
/** Get Ship's name. Can't be modified by user. */
public String getName() {
return(name);
}
private void setName(String name) {
this.name = name;
}
}
*********************
ShipTest.java
*********************
public class ShipTest {
public static void main(String[] args) {
Ship s1 = new Ship("Ship1");
Ship s2 = new Ship(0.0, 0.0, 2.0, 135.0, "Ship2");
s1.move();
s2.move(3);
s1.printLocation();
s2.printLocation();
}
}
Aug 29