java - 如何在代码中为火球创建一个单独的类？

Question

我的代码目前可以工作，也就是说我想为火球创建一个单独的类。我不知道如何做到这一点，而且找不到任何示例，我只是在寻求有关派生单独的类的帮助，以便我的主要代码不会太大。这是代码:

import java.awt.image.BufferedImage;
import java.awt.BorderLayout;
import java.awt.Graphics;
import java.awt.MediaTracker;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.*;
import java.awt.event.KeyEvent;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import java.awt.Image;
import java.io.*;
import javax.swing.JOptionPane;
import javax.imageio.*;
import java.awt.Rectangle;
public class Main extends JPanel implements ActionListener, KeyListener{
    ImageIcon images[], imagesL[],standingImage[],punchImg[],
            fireImg[],kickImg[],jumpImg[],slamImg[];
    int x = 100, y = 530;
    int count;
    int velX,velY;
    int velF;
    int firey,firex;
    int gravity = 20;
    int totalImages =3, currentImage = 0, animationDelay = 80,
            numSlam = 3,currentSlam = 0, numberImages = 1,
            currentStand = 0,
            numPunch = 3, currentPunch = 0;

    int currentFire = 0, numFire =1,totalImagesL =3,
            currentImageL =     0,currentKick = 0, numKick=2,currentJump = 0,
            numJump = 1;
    int height, totalHeight = -120;
    int  velEnemy = 5;
    int counter;
    int enemyX = 310;
    Timer animationTimer;
    boolean isMovingLeft;
    boolean isKick;
    boolean isFire = false, fireIs = false,isMovingRight = false,
            isNotMoving = true, isPunch = false, startFire = false, isJump = false,
            isSlam = false;
    boolean  enemyIsDead = false;
    Image fireball;
    Image back;
    Image title;
    Image alien;
    long lastJumptime = 0;
    long lastrJumptime = 0;
    long currentTime;
    long lastFiretime = 0;
    private final int FRAME_DELAY = 50;
    public Main() {
        setFocusable(true); // make your panel focusable
        addKeyListener(this); // register the key listener
        setFocusTraversalKeysEnabled(false);
        //WALKING/RUNNING RIGHT//
        images = new ImageIcon[totalImages];
        images[2] = new ImageIcon("standing.png");
        images[1] = new ImageIcon("midWay.png");
        images[0] = new ImageIcon("running.png");
        //WALKING/RUNNING LEFT//
        imagesL = new ImageIcon[totalImagesL];
        imagesL[2] = new ImageIcon("standingL.png");
        imagesL[1] = new ImageIcon("midWayL.png");
        imagesL[0] = new ImageIcon("runningL.png");
        ///STANDING STILL
        standingImage = new ImageIcon[numberImages];
        standingImage[0] = new ImageIcon("standing.png");
        //PUNCH/////
        punchImg = new ImageIcon[numPunch];
        punchImg[0] = new ImageIcon("midPunch.png");
        punchImg[1] = new ImageIcon("punchFull.png");
        punchImg[2] = new ImageIcon("midPunch.png");
        //COMMENCE FIREBALL//
        fireImg = new ImageIcon[numFire];
        fireImg[0] = new ImageIcon("startFire.png");
        //COMMENCE KICK//
        kickImg = new ImageIcon[numKick];
        kickImg[0]= new ImageIcon("startKick.png");
        kickImg[1]= new ImageIcon("finishKick.png");
        //JUMPING//
        jumpImg = new ImageIcon[numJump];
        jumpImg[0] = new ImageIcon("ready.png");
        //TITLE THINGY///
        ImageIcon title = new ImageIcon("gokuTitle.png");
        //SLAM THINGY//
        slamImg = new ImageIcon[numSlam];
        slamImg[0] = new ImageIcon("startSlam.png");
        slamImg[1] = new ImageIcon("midSlam.png");
        slamImg[2] = new ImageIcon("endSlam.png");
        startAnimation();
    }

    public void paintComponent(Graphics g) {
        //SOUND FOR THIS STUFF//
        Sound[] soundSelection = new Sound[4];
        soundSelection[0]= new Sound("Fire Spell.wav");
        soundSelection[1] = new Sound("kick effect.wav");
        soundSelection[2] = new Sound("fire ball troll.wav");
        soundSelection[3] = new Sound("punch sound effect.wav");
        //END STUFF FOR SOUND//
        super.paintComponent(g);
        Graphics g2 = (Graphics) g;
        try{
            back = ImageIO.read(new File("backGround.png"));
            title = ImageIO.read(new File("gokuTitle.png"));
        }catch (IOException e) {
        }
        g2.drawImage(back, 0, 0, null);
        g2.drawImage(title, 0, 0, null);
        if (isMovingRight == true){//if moving right
            if (images[currentImage].getImageLoadStatus() == MediaTracker.COMPLETE) {
                Image imgRun =  images[currentImage].getImage();
                g2.drawImage(imgRun, x, y, null);
                currentImage = (currentImage + 1) % totalImages;
            }
        }
        if (isMovingLeft == true){//if moving left
            if (imagesL[currentImageL].getImageLoadStatus() == MediaTracker.COMPLETE)
            {
                Image imgRunL =  imagesL[currentImageL].getImage();
                g2.drawImage(imgRunL, x, y, null);
                currentImageL = (currentImageL + 1) % totalImagesL;
            }
        }
        if (isNotMoving == true){//IF not moving
            if (standingImage[currentStand].getImageLoadStatus() == MediaTracker.COMPLETE) {
                Image imgStand = standingImage[currentStand].getImage();
                g2.drawImage(imgStand, x, y, null);
                currentStand = (currentStand + 1) % numberImages;
            }
        }
        if (fireIs== true){
            //Do a seperate class for fireball
            isFire = true;
            if (fireImg[currentFire].getImageLoadStatus() == MediaTracker.COMPLETE) {
                Image  fireMe = fireImg[currentFire].getImage();
                g2.drawImage(fireMe, x, y, null);
                currentFire = (currentFire+ 1) % numFire;
                soundSelection[0].play();
                soundSelection[2].play();
            }
            try{
                fireball = ImageIO.read(new File("fireball.png"));
            }catch (IOException e) {
            }
        }
        if(isFire ==true){
            fireIs = false;
            g2.drawImage(fireball, firex + 80, firey+30, null);
        }
        if(isPunch == true){
            if (punchImg[currentPunch].getImageLoadStatus() == MediaTracker.COMPLETE) {
                Image punchMe = punchImg[currentPunch].getImage();
                g2.drawImage(punchMe, x, y, null);
                currentPunch = (currentPunch+ 1) % numPunch;
                soundSelection[3].play();
            }
        }
        if(isKick == true){
            if (kickImg[currentKick].getImageLoadStatus() == MediaTracker.COMPLETE) {
                Image kickMe = kickImg[currentKick].getImage();
                g2.drawImage(kickMe, x, y, null);
                currentKick = (currentKick+ 1) % numKick;
                soundSelection[1].play();
            }
        }
        if (isJump == true){
            if (jumpImg[currentJump].getImageLoadStatus() == MediaTracker.COMPLETE) {
                Image jumpUp = jumpImg[currentJump].getImage();
                g2.drawImage(jumpUp,x, y+10, null);
                currentJump = (currentJump+ 1) % numJump;
            }
        }
        if (isSlam == true){
            if (slamImg[currentSlam].getImageLoadStatus() == MediaTracker.COMPLETE) {
                Image slamUp = slamImg[currentSlam].getImage();
                g2.drawImage(slamUp,x, y+10, null);
                currentSlam = (currentSlam+ 1) % numSlam;
            }
        }
        //ENEMY THAT DOES NOT WANT TO WORK//

        //draw rect here//
        Rectangle player = new Rectangle(x,y, 60,100);
        Rectangle enemies = new Rectangle(enemyX,530, 60,100);
        /////
        if (player.intersects(enemies)){
            enemyIsDead = true;
        }
        if (enemyIsDead == false){
            try{
                alien = ImageIO.read(new File("Alien1.png"));
            }catch (IOException e) {
            }
            g2.drawImage(alien, enemyX, 530, null);
        }


    }

    public void actionPerformed(ActionEvent e) {
        repaint();
        try {
            Thread.sleep(FRAME_DELAY);
        } catch (InterruptedException exception) {
            throw new RuntimeException(exception);
        }
        x+=velX;
        height += velY;
        enemyX+=velEnemy;
        if (height >= totalHeight){
            y+=velY;
        }else{
            y+=gravity;
        }
        firex += velF;
        if (y < 2){
            y = 3;
        }
        if (y >530){
            y = 531;
        }
    }
    public void right(){
        velX = 20;
    }
    public void left(){
        velX = -20;
    }
    public void fire(){
        velF = 30;
    }
    public void jump(){
        velY = -30;
    }
    public void notMovingMethod(){
        isMovingRight = false;
        isNotMoving = true;
        isPunch = false;
        isMovingLeft = false;
        isKick  = false;
        isJump = false;
        isSlam = false;
    }
    public void everythingFalse(){
        isPunch = false;
        isNotMoving = false;
        isMovingRight = false;
        isMovingLeft = false;
        isKick  = false;
        isJump = false;
        isSlam = false;
    }
    public void keyPressed(KeyEvent e) {
        int code = e.getKeyCode();
        //FIND OUT ABOUT COUNTER FOR ENEMIES NEARBY,LIKE IF AN ENEMY IS NEAR YOU FOR 
        2 SEC YOU LOSE HEALTH
        if(code == KeyEvent.VK_Z){
            currentTime=System.currentTimeMillis();
            if (currentTime >= lastFiretime + 5000){
                firex = x;
                firey = y;
                fire();
                fireIs = true;
                everythingFalse();
                lastFiretime=System.currentTimeMillis();
            }
        }
        if (code == KeyEvent.VK_P){
            System.out.println("Paused");
            stopAnimation();
        }
        if (code == KeyEvent.VK_A){
            left();
            everythingFalse();
            isMovingLeft = true;

        }

        if (code == KeyEvent.VK_F){
            everythingFalse();
            isPunch = true;
        }

        if(code == KeyEvent.VK_D){
            right();
            everythingFalse();
            isMovingRight = true;
        }
        if(code == KeyEvent.VK_Q){
            everythingFalse();
            isKick  = true;
        }
        if(code == KeyEvent.VK_W){
            currentTime=System.currentTimeMillis();
            if (currentTime >= lastJumptime + 1000){
                jump();
                everythingFalse();
                isJump = true;
                lastJumptime=System.currentTimeMillis();
            }
        }
        if (code == KeyEvent.VK_E){
            everythingFalse();
            isSlam = true;
        }
    }
    public void keyTyped(KeyEvent e){}
    public void keyReleased(KeyEvent e){
        int code = e.getKeyCode();

        if(code == KeyEvent.VK_D){
            notMovingMethod();
        }
        if (code == KeyEvent.VK_P){
            startAnimation();
        }
        if (code == KeyEvent.VK_A){
            notMovingMethod();
        }
        if(code == KeyEvent.VK_Q){
            notMovingMethod();
        }
        if (code == KeyEvent.VK_F){
            notMovingMethod();
        }
        if (code == KeyEvent.VK_E){
            notMovingMethod();
        }
        if(code == KeyEvent.VK_Z){
            notMovingMethod();
        }
        if(code == KeyEvent.VK_W){
            currentTime=System.currentTimeMillis();
            if (currentTime >= lastrJumptime + 1000){
                notMovingMethod();
                height = 0;
            }
            lastrJumptime = System.currentTimeMillis();
        }
        velX = 0;
    }
    public void startAnimation() {
        if (animationTimer == null) {
            currentImage = 0;
            currentImageL = 0;
            currentStand = 0;
            currentPunch=0;
            currentFire = 0;
            currentKick = 0;
            currentJump = 0;
            currentSlam = 0;
            animationTimer = new Timer(animationDelay, this);
            animationTimer.start();
        } else if (!animationTimer.isRunning())
            animationTimer.restart();
    }

    public void stopAnimation() {
        animationTimer.stop();
    }
}

Answer 1

嗯，我很高兴您询问如何使用单独的类，因为根据您发布的代码，您非常需要它们。不只是为了火球。对于声音，对于动画，对于玩家，对于敌人。每个类应该只有一个职责，这是您的代码不会做的事情，但它会使其更加清晰和可维护。

要回答您的问题，请使用新类创建一个新的 .java 文件，如下所示:

public class Fireball {
    public Fireball() {
        //do whatever you need to do in the constructor
    }

    //you can declare other methods of fireballs here
}

然后使用 import 语句将其包含在您的主类中。

有关单一职责原则的更多信息:https://en.wikipedia.org/wiki/Single_responsibility_principle

类的基本概述 - 如果您刚刚决定第一次使用不同的类，这是最好的起点:https://docs.oracle.com/javase/tutorial/java/javaOO/classes.html