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我正在用 Java 编写 Flappy Bird 游戏的副本，但我在一些关于线程的事情上遇到了挫折。基本上，到目前为止，我的项目中有 4 个类。我有一个Renderer类可以帮助我渲染游戏，看起来像这样：

import java.awt.Graphics;

import javax.swing.JPanel;

public class Renderer extends JPanel
{

    private static final long serialVersionUID = 1L;

    @Override
    protected void paintComponent(Graphics g)
    {
        super.paintComponent(g);

        FlappyBird.flappyBird.repaint(g);
    }

}

我有一个Database课程可以帮助我连接到本地托管数据库以保存分数，它看起来像这样：

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;  
import java.sql.SQLException;
import java.sql.Statement;

public class Database  {

    private static Connection con;
    private String driverName = "com.mysql.jdbc.Driver";

    public Database(String host, String username, String password){
       try {

            con = DriverManager.getConnection( host, username, password );

           }

       catch (SQLException e) {
        System.out.println(e.getMessage());
        e.printStackTrace();
       }

       try {
            Class.forName(driverName).newInstance();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            System.err.println(e.getMessage() + "------Cannot Load Driver");

        }
   }

    public void insertRow (Row row)
   {
        try {         

            PreparedStatement stmt = con.prepareStatement("insert into Scores (Username, Score, CoinScore) VALUES (?, ?, ?);");
            stmt.setString(1, row.getUserName());
            stmt.setInt(2, row.getScore());
            stmt.setInt(3, row.getCoinScore());


            stmt.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
            e.printStackTrace();
        }
    }
}

我有一个Row类，它代表即将插入数据库的单行，其文件如下所示：

public class Row {

    private String username;
    private int score;
    private int coinscore;

    public Row(String username, int score, int coinscore)
    {
        this.username = username;
        this.score = score;
        this.coinscore = coinscore;
    }

    public String getUserName()
    {
        return this.username;
    }

    public int getScore()
    {
        return this.score;
    }

    public int getCoinScore()
    {
        return this.coinscore;
    }
}

我有一个名为的主类Flappy Bird，它是游戏本身，看起来像这样：

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.*;
import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;

import javax.swing.JFrame;
import javax.swing.Timer;


public class FlappyBird implements ActionListener, MouseListener, KeyListener
{

    public static FlappyBird flappyBird;

    public final int WIDTH = 800, HEIGHT = 800;

    public Renderer renderer;

    public Rectangle bird;

    public ArrayList<Rectangle> columns,coins;

    public int ticks, yMotion, score, coinScore;

    public boolean gameOver, started;

    public Random rand;

    public Timer timer;

    public FlappyBird()
    {
        JFrame jframe = new JFrame();
        timer = new Timer(50, this);

        renderer = new Renderer();
        rand = new Random();

        jframe.add(renderer);
        jframe.setTitle("Flappy Bird");
        jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jframe.setSize(WIDTH, HEIGHT);
        jframe.addMouseListener(this);
        jframe.addKeyListener(this);
        jframe.setResizable(false);
        jframe.setVisible(true);

        bird = new Rectangle(WIDTH / 2 - 10, HEIGHT / 2 - 10, 20, 20);
        columns = new ArrayList<Rectangle>();
        coins = new ArrayList<Rectangle>();

        addColumn(true);
        addColumn(true);
        addColumn(true);
        addColumn(true);

        timer.start();
    }

    public void addColumn(boolean start)
    {
        int space = 300;
        int width = 100;
        int height = 50 + rand.nextInt(300);

        if (start)
        {
            columns.add(new Rectangle(WIDTH + width + columns.size() * 300, HEIGHT - height - 120, width, height));
            coins.add(new Rectangle(WIDTH+10+columns.size()*300,HEIGHT-height-100,15,15));
            columns.add(new Rectangle(WIDTH + width + (columns.size() - 1) * 300, 0, width, HEIGHT - height - space));
        }
        else
        {
            columns.add(new Rectangle(columns.get(columns.size() - 1).x + 600, HEIGHT - height - 120, width, height));
            coins.add(new Rectangle(columns.get(columns.size()-1).x+rand.nextInt(600) + 100,HEIGHT -height - rand.nextInt(100),15,15));
            columns.add(new Rectangle(columns.get(columns.size() - 1).x, 0, width, HEIGHT - height - space));
        }
    }

    public void paintColumn(Graphics g, Rectangle column)
    {
        g.setColor(Color.green.darker());
        g.fillRect(column.x, column.y, column.width, column.height);
    }

    public void paintCoin(Graphics g, Rectangle coin)
    {
        g.setColor(Color.yellow.darker());
        g.fillRect(coin.x, coin.y, coin.width, coin.height);
    }

    public void paintCoinCyan(Graphics g, Rectangle coin)
    {
        g.setColor(Color.cyan);
        g.fillRect(coin.x, coin.y, coin.width, coin.height);
    }

    public void jump()
    {
        if (gameOver)
        {
            bird = new Rectangle(WIDTH / 2 - 10, HEIGHT / 2 - 10, 20, 20);
            columns.clear();
            coins.clear();
            yMotion = 0;
            score = 0;
            coinScore = 0;

            addColumn(true);
            addColumn(true);
            addColumn(true);
            addColumn(true);
           Scanner in = new Scanner(System.in);
           Database myDB = new Database("jdbc:mysql://localhost:3306/Leaderboard","root","greenlantern10");
           System.out.println("Input your Username: ");
           String user = in.next();
           in.close();

           Row row = new Row(user,score,coinScore);
           myDB.insertRow(row);
            gameOver = false;


        }

        if (!started)
        {
            started = true;
        }
        else if (!gameOver)
        {
            if (yMotion > 0)
            {
                yMotion = 0;
            }

            yMotion -= 10;
        }
    }



    @Override
    public void actionPerformed(ActionEvent e)
    {
        int speed = 15;

        ticks++;

        if (started)
        {
            for (int i = 0; i < columns.size(); i++)
            {
                Rectangle column = columns.get(i);

                column.x -= speed;

            }

            for (int i = 0; i< coins.size();i++)
            {
                Rectangle coin = coins.get(i);

                coin.x -= speed;

            }

            if (ticks % 2 == 0 && yMotion < speed)
            {
                yMotion += 2;
            }

            for (int i = 0; i < columns.size(); i++)
            {
                Rectangle column = columns.get(i);

                if (column.x + column.width < 0)
                {
                    columns.remove(column);

                    if (column.y == 0)
                    {
                        addColumn(false);
                    }
                }
            }

            bird.y += yMotion;

            for (Rectangle column : columns)
            {
                if (column.y == 0 && bird.x + bird.width / 2 > column.x + column.width / 2 - 10 && bird.x + bird.width / 2 < column.x + column.width / 2 + 10)
                {
                    score++;
                }

                if (column.intersects(bird))
                {
                    gameOver = true;

                    if (bird.x <= column.x)
                    {
                        bird.x = column.x - bird.width;

                    }
                    else
                    {
                        if (column.y != 0)
                        {
                            bird.y = column.y - bird.height;
                        }
                        else if (bird.y < column.height)
                        {
                            bird.y = column.height;
                        }
                    }
                }
            }

            for (Rectangle coin : coins)
            {
                if (bird.intersects(coin))
                {
                  coinScore++;

                }
            }

            if (bird.y > HEIGHT - 120)
            {
                bird.y = HEIGHT - 120;
            }

            if (bird.y < 0)
            {
                gameOver = true;
            }

            if (bird.y + yMotion >= HEIGHT - 120)
            {
                bird.y = HEIGHT - 120 - bird.height;
                gameOver = true;
            }
        }

        renderer.repaint();
    }

    public void repaint(Graphics g)
    {
        g.setColor(Color.cyan);
        g.fillRect(0, 0, WIDTH, HEIGHT);

        g.setColor(Color.orange);
        g.fillRect(0, HEIGHT - 120, WIDTH, 120);

        g.setColor(Color.green);
        g.fillRect(0, HEIGHT - 120, WIDTH, 20);

        g.setColor(Color.red);
        g.fillRect(bird.x, bird.y, bird.width, bird.height);

        for (Rectangle column : columns)
        {
            paintColumn(g, column);
        }

        for (Rectangle coin : coins)
        {
            paintCoin(g,coin);
        }

        g.setColor(Color.white);
        g.setFont(new Font("SANS_SERIF", 1, 100));

        if (!started)
        {
            g.drawString("Click or press SPACE to start!", 40, HEIGHT / 2 - 50);
        }

        if (gameOver)
        {
            g.drawString("Game Over!", 200, HEIGHT / 2 - 60);
        }

        if (!gameOver && started)
        {
            g.drawString("Score: "+String.valueOf(score), WIDTH / 2 - 400 , 150);
            g.drawString("Coin score: "+String.valueOf(coinScore),WIDTH / 2- 400, 50);
        }
    }

    public static void main(String[] args)
    {
        flappyBird = new FlappyBird();
    }

    @Override
    public void mouseClicked(MouseEvent e)
    {
        jump();
    }

    @Override
    public void keyReleased(KeyEvent e)
    {
        if (e.getKeyCode() == KeyEvent.VK_SPACE)
        {
            jump();
        }
    }

    @Override
    public void mousePressed(MouseEvent e)
    {
    }

    @Override
    public void mouseReleased(MouseEvent e)
    {
    }

    @Override
    public void mouseEntered(MouseEvent e)
    {
    }

    @Override
    public void mouseExited(MouseEvent e)
    {
    }

    @Override
    public void keyTyped(KeyEvent e)
    {

    }

    @Override
    public void keyPressed(KeyEvent e)
    {

    }

}

当我尝试在数据库中插入新行时出现问题（当设置了 gameover 变量时，即 gameover = true）。显然，应用程序正确地插入了数据库，但是当我尝试重玩游戏时，我收到一些关于事件调度线程的异常并且游戏不再继续。到目前为止，我尝试在将数据插入数据库时​​停止计时器，然后重新启动它，但没有奏效。你有什么意见，我应该怎么做才能解决这个问题？

PS：除了这个问题，游戏运行没有任何问题。

堆栈跟踪：

Exception in thread "AWT-EventQueue-0" java.util.NoSuchElementException
    at java.util.Scanner.throwFor(Unknown Source)
    at java.util.Scanner.next(Unknown Source)
    at flappyBird.FlappyBird.jump(FlappyBird.java:128)
    at flappyBird.FlappyBird.keyReleased(FlappyBird.java:322)
    at java.awt.Component.processKeyEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Window.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.KeyboardFocusManager.redispatchEvent(Unknown Source)
    at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(Unknown Source)
    at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(Unknown Source)
    at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(Unknown Source)
    at java.awt.DefaultKeyboardFocusManager.dispatchEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$500(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)
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1 回答 1

0

在 Jump 例程中，您放错了代码。它基本上尝试在跳转中扫描玩家（名称）输入。

您的逻辑让您两次执行此例程，第二次失败。很可能由于在游戏之间收集的 System.in 输入而失败。

在查询之前刷新您的 System.in，或者更好的是，使用 Swing 库在游戏中实际询问玩家姓名。

于 2016-01-13T20:04:29.500 回答