[Java] compile errors

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  • uppie8374
  • Registratie: Maart 2002
  • Laatst online: 11-01 19:54
Wanneer ik dit probeer te compilen :

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        // An illustration of using a method that returns a result.
class ShipMain5 {
    public static void main(String[] args){
        // Define a method variable and make it refer to a
        // newly constructed Ship object.
        Ship argo = new Ship();

        // Ask the ship to report its initial position, course and speed.
        argo.report();

        // Define a variable to hold the ship's current speed.
        double currentSpeed;
        // Ask the ship what its current speed is.
        currentSpeed = argo.getSpeed();
        // Increase the ship's speed.
        argo.setSpeed(currentSpeed+1);

        // Ask the ship to move and report.
        argo.move();
        argo.report();
    }
}


Krijg ik deze foutmelding :

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ShipMain5.java:6: cannot resolve symbol
symbol   : class Ship
location  : class ShipMain5
              Ship argo = new Ship();
              ^                                   
ShipMain5.java:6: cannot resolve symbol
symbol   :  class Ship
location  :  class ShipMain5
              Ship argo = new Ship();
                              ^
2 errors



Het bestand Ship.class heb ik gewoon in dezelfde directory staan.

Ik ben nog vrij nieuw in het programmeren met Java ( zit al helemaal in hoofdstuk 3 :*) ) dus wie wil mij helpen.

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  • Glimi
  • Registratie: Augustus 2000
  • Niet online

Glimi

Designer Drugs

(overleden)
Heb je ook nog een package statement boven deze code staan? En komt die overeen met het package statement van de code van Ship.java?

  • ^Mo^
  • Registratie: Januari 2001
  • Laatst online: 04-11-2025
compile je de file Ship.java ook wel? Misschien een stomme vraag....
Laat anders een de class declaratie van Ship zien, misschien typo gemaakt?

"There are 10 kinds of people in the world, those who understand binary and those who don't" | Werkbak specs


  • _-= Erikje =-_
  • Registratie: Maart 2000
  • Laatst online: 01-09 12:46
volgens mij staan er wat wasige regeleindes in je javafiles of zo (zeker die 2e foutmelding)

  • uppie8374
  • Registratie: Maart 2002
  • Laatst online: 11-01 19:54
Ok de code van Ship.java (ja deze staat er ook gecompiled)

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import java.text.NumberFormat;
import java.util.Observable;
import java.io.*;

        /** Definition of a Ship class with position,
         *  speed, course and name information.
         *  @author David J. Barnes (d.j.barnes@ukc.ac.uk)
         *  @version Version 2.0 (14th Apr 1999)<br>
         */
public class Ship extends Observable implements Runnable {
        /** Default X position. */
    public static final double DEFAULT_X = 25.0;
        /** Default Y position. */
    public static final double DEFAULT_Y = 25.0;
        /** Default course. */
    public static final double DEFAULT_COURSE = 0.0;
        /** Default speed. */
    public static final double DEFAULT_SPEED = 5.0;

        /** Construct with explicit position, course, speed and name.
         */
    public Ship(double x, double y, double course, double speed,String name){
        setSpeed(speed);
        setPosition(x,y);
        setCourse(course);
        this.name = name;

        // Am I the first?
        if(getFormatter() == null){
            formatter = NumberFormat.getNumberInstance();
            // Print to two decimal places.
            formatter.setMaximumFractionDigits(2);
            setFormatter(formatter);
        }

        // Add myself to the GUI.
        sea.add(this);
    }

        /** Construct with explicit position, course and speed.
         *  The ship has no name.
         */
    public Ship(double x, double y, double course, double speed){
        this(x,y,course,speed,"");
    }

        /** Construct with explicit position and course.
         *  The ship has no name.
         */
    public Ship(double x, double y, double course){
        this(x,y,course,DEFAULT_SPEED);
    }

        /** Construct with explicit position.
         *  The ship has no name.
         */
    public Ship(double x, double y){
        this(x,y,DEFAULT_COURSE);
    }

        /** Construct with default position, course and speed.
         *  The ship has no name.
         */
    public Ship(){
        // Set default position, course and speed for this ship.
        this(DEFAULT_X,DEFAULT_Y);
    }

        /** Construct with a name.
         */
    public Ship(String name){
        this(DEFAULT_X,DEFAULT_Y,DEFAULT_COURSE,DEFAULT_SPEED,name);
    }

        /** Set the ship's position.
         */
    public void setPosition(double x, double y){
        setPosition(new Position(x,y));
        radarBlip();
    }

        /** Set the ship's position.
         */
    public void setPosition(Position newPosition){
        position = newPosition;
    }

        /** Set the ship's speed.
         *  @param newSpeed A positive or negative value.
         */
    public void setSpeed(double newSpeed){
        speed = newSpeed;
    }

        /** Set the ship's course.
         *  @param newCourse The course in degrees. Values are
         *  adjusted to the range [0..360)
         */
    public void setCourse(double newCourse){
        // Make sure it is in the range [0..360)
        final double numDegrees = 360.0;
        if(newCourse < 0){
            newCourse = numDegrees+(newCourse%numDegrees);
        }
        course = newCourse % numDegrees;
        radarBlip();
    }

        /** Report the ship's position, course and speed.
         *  Reporting is done via the ship's current.
         *  @see #getWriter()
         *  @see #setWriter(PrintWriter)
         */
    public void report(){
        Position p = getPosition();
        NumberFormat formatter = getFormatter();
        PrintWriter writer = getWriter();

        String name = getName();
        if((name != null) && !name.equals("")){
            writer.print(name+": ");
        }
        writer.print("Position is ("+formatter.format(p.getX())+","+
                                   formatter.format(p.getY())+"), ");
        writer.print("Course is "+formatter.format(getCourse())+", ");
        writer.print("Speed is "+formatter.format(getSpeed()));
        writer.println();
        writer.flush();
    }

        /** Move the ship according to its current speed and position.
         */
    public void move(){
        double radians = Math.toRadians(getCourse());
        Position p = getPosition();
        setPosition(p.getX()+speed*Math.cos(radians),
                    p.getY()+speed*Math.sin(radians));
    }

        /** An implementation of the Runnable interface, to enable a Ship
         *  to be run in an independent thread, if required.
         *  @see java.lang.Runnable
         */
    public void run(){
        while(true){
            move();
            report();
            // Be prepared to yield, in case we are not sleeping for
            // some reason.
            Thread.yield();
        }
    }

        /** Return the current position.
         *  @see Position
         */
    public Position getPosition(){
        return new Position(position.getX(),position.getY());
    }

        /** Return the current course.
         */
    public double getCourse(){
        return course;
    }

        /** Return the current speed.
         */
    public double getSpeed(){
        return speed;
    }

        /** Return the current name.
         */
    public String getName(){
        return name;
    }

        /** Return the current course and position.
         *  @see CourseAndPosition
         */
    public CourseAndPosition getCourseAndPosition(){
        return new CourseAndPosition(getCourse(),getPosition());
    }

        /** Get the writer to be used for reporting.
         *  @see #report()
         */
    public PrintWriter getWriter(){
        return writer;
    }

        /** Set the writer to be used for reporting.
         *  @see #report()
         */
    public void setWriter(PrintWriter w){
        writer = w;
    }

        /** Notify any observers of a significant change.
         */
    protected void radarBlip(){
        setChanged();
        notifyObservers(getCourseAndPosition());
        // Give the UI a chance to display us.
        delay();
    }

        /** Make the animation a little easier to follow.
         *  Sleep for a time related to the ship's speed.
         *  @see #getDelayTime()
         *  @see #setDelayTime(int)
         */
    protected void delay(){
        try{
            final int maxSleepTime = getDelayTime();
            int sleepTime;
            final double speed = getSpeed();
            if(speed == 0){
                sleepTime = maxSleepTime;
            }
            else{
                sleepTime = (int) Math.abs(maxSleepTime/speed);
            }
            Thread.sleep(sleepTime);
        }
        catch(InterruptedException e){
        }
    }

    protected NumberFormat getFormatter(){
        return formatter;
    }

    protected void setFormatter(NumberFormat f){
        formatter = f;
    }

        /** Get the delay time (in milliseconds) used by the animation.
         */
    protected int getDelayTime(){
        return delayTime;
    }

        /** Set the delay time used by the animation.
         *  @param delay The delay time in milliseconds.
         */
    protected void setDelayTime(int delay){
        if(delay >= 0){
            delayTime = delay;
        }
    }

    // (x,y) co-ordinates in the ocean.
    private Position position;
    // Speed and course
    private double speed;
    // Keep degrees in the range [0..360)
    private double course;
    // A name for the ship.
    private final String name;

    // The GUI used to display ships. Shared by them all.
    private static final SeaGUI sea = new SeaGUI();
    // A formatter used in reporting. Shared by all ships.
    private static NumberFormat formatter;
    // How long to delay between moves, to make the animation easier
    // to follow. A value in milliseconds.
    private int delayTime = 4000;
    // Where reports are printed to. Standard output by default.
    private PrintWriter writer = new PrintWriter(System.out);
}


Let wel ik heb dit niet geprogrammeerd, dit zijn voorbeelden die bij mijn boek zitten waar ik mee aan de slag moet. Maar als het zo al niet werkt , hoe kan ik er dan mee aan de slag :*)

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  • uppie8374
  • Registratie: Maart 2002
  • Laatst online: 11-01 19:54
_-= Erikje =-_ schreef op 14 augustus 2002 @ 22:10:
volgens mij staan er wat wasige regeleindes in je javafiles of zo (zeker die 2e foutmelding)
Opgelost ook al moet ik het in het bericht nou ergens voor het = teken zetten |:(

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