1

EDIT: updated code and question

I added main() method as stated in aswers but I still can't export it. I am running my program as Java Applet, and apparently I need to use Java Application to run it standalone, but when I change run configuration to Application i get these errors: 

Exception in thread "main" java.lang.NullPointerException at acm.graphics.GImage.determineSize(GImage.java:564) at acm.graphics.GImage.setImage(GImage.java:173) at acm.graphics.GImage.<init>(GImage.java:115) at acm.graphics.GImage.<init>(GImage.java:54) at Pong.createTexture(Pong.java:160) at Pong.run(Pong.java:81) at Pong.main(Pong.java:55)

I need to export my project from Eclipse as a standalone runnable JAR, but when i go to export -> java -> JAR file i dont see any classes to select and im getting stuck at this (screen) window. I only have one class in my project.

This is not relevant anymore but I'll leave it here to keep edit history

import java.awt.Color; import java.awt.Image; import java.awt.event.MouseEvent; import java.util.Random; import acm.graphics.GImage; import acm.graphics.GLabel; import acm.graphics.GObject; import acm.graphics.GOval; import acm.graphics.GRect; import acm.program.GraphicsProgram; /* TO DO LIST * ------------------ * Corner Bounce * * * */ @SuppressWarnings("serial") public class Pong extends GraphicsProgram { public double mouseY; private static final double PAUSE = 1000 / 96.0; private Random rand = new Random(); private boolean AI_GODMODE = false; // ball public double startX; public double startY; private static final double BALL_SIZE = 20; private static final double SPEED = 5; private double ballHorizontalSpeed = SPEED * 1.5; private double ballVerticalSpeed = SPEED; // paddle private static int HEIGHT = 150; private static int WIDTH = 15; private static int COUNTER = 0; private static int AI_SPEED = 10; // AI difficulty 1-20 // label public int AI_SCORE = 0; public int PLAYER_SCORE = 0; public int TOTAL_GAMES = 0; private float TRANSPARENCY = 0.0f; // counters private static final int PADDING = 10; private static final int MODIFIER = 3; public static void main(String[] args) { Pong p = new Pong(); p.run(); } public void run() { addMouseListeners(); // counters setup GLabel counter = new GLabel(String.valueOf(COUNTER)); GLabel aiScore = new GLabel(String.valueOf(AI_SCORE)); GLabel average = new GLabel(String.valueOf("Avg: 0")); GLabel playerScore = new GLabel(String.valueOf(COUNTER)); Color labelC = new Color(0, 0.0f, 0.0f, TRANSPARENCY); Color scoreC = new Color(0, 0.0f, 0.0f, 0.1f); counter.setFont("Impact-600"); aiScore.setFont("Impact-100"); average.setFont("Impact-50"); playerScore.setFont("Impact-100"); counter.setColor(labelC); aiScore.setColor(scoreC); playerScore.setColor(scoreC); average.setColor(scoreC); counter.setLocation(getWidth() / 2 - counter.getWidth() / 2, getHeight() / 2 + counter.getHeight() / 3.2); counter.sendToFront(); // make objects GImage paddleLeftTexture = createTexture("texture.png", WIDTH + 1, HEIGHT + 1); GImage paddleRightTexture = createTexture("texture2.png", WIDTH + 1, HEIGHT + 1); GImage ballTexture = createTexture("ballTexture.png", (int) BALL_SIZE, (int) BALL_SIZE); GImage greenFlash = createTexture("greenFlash.png", 100, 300); GImage blueFlash = createTexture("blueFlash.png", 100, 300); GOval ball = makeBall(); GRect paddleLeft = makePaddle(); GRect paddleRight = makePaddle(); greenFlash.setLocation(-200, 0); blueFlash.setLocation(-200, 0); // generate GUI drawGraphics(ball, paddleLeftTexture, paddleRightTexture, ballTexture, greenFlash, blueFlash, counter, paddleLeft, paddleRight, aiScore, playerScore, average); // game start bounce(labelC, aiScore, playerScore, counter, ball, paddleLeft, paddleRight, paddleLeftTexture, paddleRightTexture, ballTexture, greenFlash, blueFlash, average); } public void bounce(Color labelC, GLabel aiScore, GLabel playerScore, GLabel counter, GOval ball, GRect paddleLeft, GRect paddleRight, GImage paddleLeftTexture, GImage paddleRightTexture, GImage ballTexture, GImage greenFlash, GImage blueFlash, GLabel average) { preGameSetup(ball, paddleRight, paddleRightTexture, counter); updateAiScore(aiScore); updatePlayerScore(playerScore); updateAverage(average); while (true) { moveBall(ballHorizontalSpeed, ballVerticalSpeed, ball, ballTexture); movePlayerPaddle(paddleLeft, paddleLeftTexture); moveAiPaddle(ball, paddleRight, paddleRightTexture); detectHit(ball, paddleRight, paddleLeft, counter, labelC); if (TRANSPARENCY >= 0.0f) { TRANSPARENCY -= TRANSPARENCY / 100f; } labelC = new Color(0, 0.0f, 0.0f, TRANSPARENCY); counter.setColor(labelC); if (detectBallOffScreen(ball)) { ballOffScreen(ball, ballTexture, aiScore, playerScore, greenFlash, blueFlash, average); COUNTER = 0; bounce(labelC, aiScore, playerScore, counter, ball, paddleLeft, paddleRight, paddleLeftTexture, paddleRightTexture, ballTexture, greenFlash, blueFlash, average); } pause(PAUSE); } } public static GRect makePaddle() { GRect result = new GRect(0, 0, WIDTH, HEIGHT); result.setFilled(true); result.setColor(Color.BLACK); return result; } public static GOval makeBall() { GOval result = new GOval(150, 100, BALL_SIZE, BALL_SIZE); result.setFilled(true); result.setColor(Color.WHITE); return result; } private GImage createTexture(String importedImage, int width, int height) { Image importResult = getImage(getCodeBase(), importedImage); GImage textureResult = new GImage(importResult); textureResult.setSize(width, height); return textureResult; } public void mouseMoved(MouseEvent e) { mouseY = e.getY(); } private boolean ballHitBottom(GOval ball) { double bottomY = ball.getY() + ball.getHeight(); return bottomY >= getHeight(); } private boolean ballHitTop(GOval ball) { double topY = ball.getY(); return topY <= 0; } private boolean ballHitPaddleRight(GOval ball, GRect paddle) { double rightX = ball.getX() + ball.getWidth(); double rightY = ball.getY() + ball.getHeight() / 2; double paddlePosX = paddle.getX(); double paddlePosY = paddle.getY(); if (rightX >= paddlePosX && rightY >= paddlePosY && rightY <= paddlePosY + paddle.getHeight()) return true; else return false; } private boolean detectBallOffScreen(GOval ball) { if (ball.getX() < 2 * WIDTH - BALL_SIZE || ball.getX() > getWidth() - 2 * WIDTH) return true; else return false; } private boolean ballHitPaddleLeft(GOval ball, GRect paddle) { double leftX = ball.getX(); double leftY = ball.getY(); double paddlePosX = paddle.getX() + WIDTH; double paddlePosY = paddle.getY(); if (leftX <= paddlePosX && leftY >= paddlePosY && leftY <= paddlePosY + paddle.getHeight()) return true; else return false; } /* * private boolean ballHitPaddleBorder(GOval ball, GRect paddle) { ; if * (ball.getX() > paddle.getX() - BALL_SIZE && ball.getX() < paddle.getX() + * WIDTH && ball.getY() > paddle.getY() && ball.getY() < paddle.getY() + * ballVerticalSpeed) return true; else if (ball.getX() > paddle.getX() - * BALL_SIZE && ball.getX() < paddle.getX() + WIDTH && ball.getY() > * paddle.getY() + HEIGHT && ball.getY() < paddle.getY() + HEIGHT - * ballVerticalSpeed) return true; else return false; } */ private void preGameSetup(GObject ball, GObject paddleRight, GObject paddleRightTexture, GLabel counter) { startX = rand.nextInt((int) (getWidth() * 0.8)) + (int) (0.1 * getWidth()); // zapobiega pojawieniu się piłki po // lewej stronie lewej paletki startY = rand.nextInt(getHeight()); ball.setLocation(startX, startY); paddleRightTexture.setLocation(getWidth() - MODIFIER * WIDTH, startY - HEIGHT / 2); paddleRight.setLocation(getWidth() - MODIFIER * WIDTH, startY - HEIGHT / 2); paddleRightTexture.sendToFront(); counter.setLabel(String.valueOf(COUNTER)); counter.setLocation(getWidth() / 2 - counter.getWidth() / 2, getHeight() / 2 + counter.getHeight() / 3.2); ballHorizontalSpeed = SPEED * 1.5; ballVerticalSpeed = SPEED; } private void updateAiScore(GLabel aiScore) { aiScore.setLabel(String.valueOf(AI_SCORE)); aiScore.setLocation(getWidth() - aiScore.getWidth() - MODIFIER * WIDTH - PADDING, getHeight() - PADDING); } private void updatePlayerScore(GLabel playerScore) { playerScore.setLabel(String.valueOf(PLAYER_SCORE)); playerScore.setLocation(MODIFIER * WIDTH + PADDING, getHeight() - PADDING); } private void updateScore(GLabel counter, Color labelC) { counter.setLabel(String.valueOf(COUNTER)); counter.setLocation(getWidth() / 2 - counter.getWidth() / 2, getHeight() / 2 + counter.getHeight() / 3.2); TRANSPARENCY = 0.1f; labelC = new Color(0, 0.0f, 0.0f, TRANSPARENCY); counter.setColor(labelC); } private void updateAverage(GLabel average) { if (TOTAL_GAMES == 0) { average.setLabel("Round: 1 Avg: 0"); } else { average.setLabel("Round: " + String.valueOf(TOTAL_GAMES + 1) + " Avg: " + String.valueOf((int) ((AI_SCORE + PLAYER_SCORE) / TOTAL_GAMES)));} average.setLocation(getWidth() / 2 - average.getWidth() / 2, getHeight() - PADDING); } private void drawGraphics(GObject ball, GObject paddleLeftTexture, GObject paddleRightTexture, GObject ballTexture, GObject greenFlash, GObject blueFlash, GObject counter, GObject paddleLeft, GObject paddleRight, GObject aiScore, GObject playerScore, GLabel average) { add(ball); add(paddleLeftTexture); add(paddleRightTexture); add(ballTexture); add(greenFlash); add(blueFlash); add(counter); add(paddleLeft); add(paddleRight); add(aiScore); add(playerScore); add(average); } private void detectHit(GOval ball, GRect paddleRight, GRect paddleLeft, GLabel counter, Color labelC) { if (ballHitBottom(ball) && ballVerticalSpeed >= 0) { ballVerticalSpeed *= -1; } if (ballHitTop(ball) && ballVerticalSpeed <= 0) { ballVerticalSpeed *= -1; } if (ballHitPaddleRight(ball, paddleRight)) { ballHorizontalSpeed *= -1; } if (ballHitPaddleLeft(ball, paddleLeft)) { ballHorizontalSpeed *= -1; COUNTER++; updateScore(counter, labelC); boolean bool = rand.nextBoolean(); if (bool) if (ballHorizontalSpeed > 0) ballHorizontalSpeed += 1; else ballHorizontalSpeed -= 1; else if (ballVerticalSpeed > 0) ballVerticalSpeed += 0.5; else ballVerticalSpeed -= 0.5; } /* * if(ballHitPaddleBorder(ball, paddleLeft)){ ballVerticalSpeed *= -1; } * * if(ballHitPaddleBorder(ball, paddleRight)){ ballVerticalSpeed *= -1; * } */ } private void ballOffScreen(GOval ball, GObject ballTexture, GLabel aiScore, GLabel playerScore, GObject greenFlash, GObject blueFlash, GLabel average) { if (ball.getX() < 2 * WIDTH - BALL_SIZE) { // left double pos = ball.getY() - greenFlash.getHeight() / 2; ballTexture.move(-ballTexture.getWidth() * 2, 0); AI_SCORE += COUNTER; TOTAL_GAMES++; updateAiScore(aiScore); updateAverage(average); for (int i = 20; i < 100; i += 5) { greenFlash.setLocation(-i, pos); pause(25); } } else { // right double pos = ball.getY() - blueFlash.getHeight() / 2; ballTexture.move(ballTexture.getWidth() * 2, 0); PLAYER_SCORE += COUNTER; TOTAL_GAMES++; updatePlayerScore(playerScore); updateAverage(average); for (int i = 20; i < 100; i += 5) { blueFlash.setLocation(getWidth() - blueFlash.getWidth() + i, pos); pause(25); } } } private void moveBall(double ballHorizontalSpeed, double ballVerticalSpeed, GObject ball, GObject ballTexture) { ball.move(ballHorizontalSpeed, ballVerticalSpeed); ballTexture.setLocation(ball.getX(), ball.getY()); ballTexture.sendToFront(); } private void movePlayerPaddle(GObject paddleLeft, GObject paddleLeftTexture) { if (mouseY < getHeight() - HEIGHT) { // Player paddleLeft.setLocation(2 * WIDTH, mouseY); paddleLeftTexture.setLocation(2 * WIDTH, mouseY); paddleLeftTexture.sendToFront(); } else { paddleLeft.setLocation(2 * WIDTH, getHeight() - HEIGHT); paddleLeftTexture.setLocation(2 * WIDTH, getHeight() - HEIGHT); paddleLeftTexture.sendToFront(); } } private void moveAiPaddle(GOval ball, GRect paddleRight, GImage paddleRightTexture) { if (AI_GODMODE == true) { // modeSelector if (ball.getY() < getHeight() - HEIGHT / 2 && ball.getY() > HEIGHT / 2) { paddleRight.setLocation(getWidth() - MODIFIER * WIDTH, ball.getY() - HEIGHT / 2); paddleRightTexture.setLocation(getWidth() - MODIFIER * WIDTH, ball.getY() - HEIGHT / 2); paddleRightTexture.sendToFront(); } else if (ball.getY() <= HEIGHT / 2) { paddleRight.setLocation(getWidth() - MODIFIER * WIDTH, 0); paddleRightTexture.setLocation(getWidth() - MODIFIER * WIDTH, -0); paddleRightTexture.sendToFront(); } else { paddleRight.setLocation(getWidth() - MODIFIER * WIDTH, getHeight() - HEIGHT); paddleRightTexture.setLocation(getWidth() - MODIFIER * WIDTH, getHeight() - HEIGHT); paddleRightTexture.sendToFront(); } } else { // end godMode if double targetY = ball.getY() + BALL_SIZE / 2; if (targetY < getHeight() - HEIGHT / 2 && targetY > HEIGHT / 2) { if (targetY < paddleRight.getY() + HEIGHT / 2) { paddleRight.move(0, -AI_SPEED); paddleRightTexture.move(0, -AI_SPEED); } else if (targetY > paddleRight.getY() + HEIGHT / 2) { paddleRight.move(0, AI_SPEED); paddleRightTexture.move(0, AI_SPEED); } } // end normalMode if } // end modeSelector if } // end moveAiPaddle void } // end class
Improve this question
4
  • If your one class doesn't have a main(String[]) method, it cant be a runnable jar. Commented Apr 2, 2014 at 17:16
  • is there any way i can add one and make it work? my main method in project is run() Commented Apr 2, 2014 at 17:19
  • In eclipse File-->Export--> type jar file It will ask to select project to create jar Commented Apr 2, 2014 at 17:19
  • Is it possible for you to place your code in the question? :) Please and thank you :) Commented Apr 2, 2014 at 17:37

3 Answers 3

Reset to default
3

Judging from the linked image, your class Pong does not have a main method. It simply cant be exported as a runnable jar file, because you could never run it. Add a main method, or export to a standard java jar file (File -> Export -> Java -> JAR file). The jar file it produces using the latter method will NOT be runnable if there is no main method, period. You have to have a main method in order to run this code stand alone, because that is the entry point for the application.

Per your comment, You will need to create an instance of the Pong class inside of the main method and invoke its run() method:

public static void main(String[] args) { Pong p = new Pong(); p.run(); }

If the run method of the Pong class is static, you wont need an instance, and you could do this:

public static void main(String[] args) { Pong.run(); }
Improve this answer
Sign up to request clarification or add additional context in comments.

7 Comments

what do i need to put in the main method? If my current method is run() can i just make void main(){ run(); } ?
ok i added the first code and it exported, but when i launch it an error appears http://scr.hu/15in/fq52b.
Run it in eclipse, or via command prompt, watch the Console window for the stack trace. If you cant figure out the stack trace, you should post a new question related to the new problem. Good luck man!
Well it works fine if i run it through eclipse... or i don't understand what you mean
Its possible that Eclipse is satisfying dependencies for you, which you havent accounted for in your export. Repeat the test only this time launch it in command prompt via the java -jar command. It should print a stack trace telling you the problem. Also, welcome to the wonderful world of deployment issues :D
|
3

You should be exporting it as a "Runnable JAR file" instead of a "JAR file". Once you choose this you should be able to use a drop down menu called "Launch configuration:", and then you can choose your export destination.

I am using Eclipse Kepler. It may not be the same for different versions.

Improve this answer

3 Comments

and where do i get the Launch configurations? from the drop down menu i can only choose one, that seems to be from my earlier project. http://scr.hu/15in/txxn3 i dont have anything named BlankKarel anymore
@user3450315 Eclipse adds your file to the allowed exports after you have run the program. (so as Mark W pointed out) you may need to add a "main" method. and then run your program. This should add your Pong class to the list of exportable classes.
@user3450315 The last thing that I can think of is that if your error is indeed being caused by the export and there isn't an error in your code, make sure you are checking "Extract required libraries into generated JAR" and also checking "Package required libraries into generated JAR".
2

Your project should contain class with main method so that you can see your project in Launch Configuration drop down list. (Eclipse Kepler)

Improve this answer

Comments

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.