【 Java 】简易交通灯

起因：
很久之前就想做做这类的小程序练手，现在才开始动工哈哈哈。
从最简单的开始做起，这次是一个交通灯。
实现了交通灯的简单显示转换循环功能。
基于 java.swing 。
先上效果图。超级超级超级简陋哈哈哈
红灯黄灯绿灯
上代码
  1 import java.awt.Color;
  2 import java.awt.Font;
  3 import java.awt.Graphics;
  4 import java.util.Timer;
  5 import java.util.TimerTask;
  6 
  7 import javax.swing.JFrame;
  8 import javax.swing.JLabel;
  9 import javax.swing.JPanel;
 10 
 11 /** 
 12  * @ClassName: TrafficLights 
 13  * @Description: 实现简单的交通灯转换功能
 14  * @author Arrack
 15  * @date 2018年1月30日 上午9:49:54 
 16  *  
 17  */
 18 public class TrafficLights extends JPanel {
 19     /* 
 20      * serialVersionUID
 21      * 相当于java类的身份证。主要用于版本控制。
 22      * serialVersionUID作用是序列化时保持版本的兼容性,
 23      * 即在版本升级时反序列化仍保持对象的唯一性。
 24      * 摘自百度知道 https://zhidao.baidu.com/question/321447087.html
 25      */
 26     private static final long serialVersionUID = 1L;
 27 
 28     /*
 29      * 定义一系列静态常量
 30      * 程序窗口宽度高度，三种颜色亮灯，为空（都熄灭）
 31      */
 32     private static final int winWidth = 500;
 33     private static final int winHeight = 300;
 34     private static final int BLANK = 0;
 35     private static final int RED = 1;
 36     private static final int YELLOW = 2;
 37     private static final int GREEN = 3;
 38 
 39     private static int color = BLANK; // 将初始状态设置为都熄灭状态
 40 
 41     /*
 42      * 计算灯的位置和大小（仅与窗口高度和宽度有关）
 43      * ps：绘制椭圆时，drawOval(int x, int y, int width, int height)
 44      *     x,y 为椭圆外接矩形左上顶点的坐标,width,height为矩形两边长。
 45      */
 46     private int ballWidth = winHeight / 3;
 47     private int ballX = winWidth / 2 - ballWidth / 2 - winWidth / 50,
 48             ballY = winHeight / 2 - ballWidth + winHeight / 15;
 49     private int ballPadding = (winWidth - 3 * ballWidth) / 4;
 50     private int yellowX = ballX;
 51     private int redX = ballX - ballPadding - ballWidth;
 52     private int greenX = ballX + ballPadding + ballWidth;
 53 
 54     /*
 55      * Label 倒计时指示
 56      */
 57     private JLabel l = new JLabel("");
 58 
 59     public TrafficLights() {
 60         l.setFont(new Font("Arial", Font.BOLD, 20));
 61         add(l);
 62     }
 63 
 64     /** 
 65      * @Title: changeLights 
 66      * @Description: 利用timer类，进行灯的变换和闪烁，并显示倒计时
 67      * @param @param timeR  红灯持续时间 单位秒
 68      * @param @param timeY  黄灯持续时间
 69      * @param @param timeG  绿灯持续时间
 70      * @return void
 71      */
 72     public void changeLights(final int timeR, final int timeY, final int timeG) {
 73         final Timer timer = new Timer();
 74         final int num = timeR + timeG + timeY;
 75         timer.schedule(new TimerTask() {
 76             int i = 1;
 77 
 78             public void run() {
 79                 i %= num;
 80                 if (i > 0 && i <= timeR) { // 红灯的时间，红灯持续亮
 81                     color = RED;
 82                     l.setText(Integer.toString(timeR + 1 - i));
 83                 } else if (i > timeR && i <= timeR + timeY) { // 黄灯的时间，黄灯闪烁，0.6s闪一次
 84                     color = YELLOW;
 85                     l.setText(Integer.toString(timeY + 1
 86                             - (i % timeY != 0 ? i % timeY : timeY)));
 87                     timer.schedule(new TimerTask() {
 88                         public void run() {
 89                             color = BLANK;
 90                             repaint();
 91                         }
 92                     }, 600);
 93                 } else { // 绿灯的时间，持续亮
 94                     color = GREEN;
 95                     l.setText(Integer.toString(timeG + 1
 96                             - (i % timeG != 0 ? i % timeG : timeG)));
 97                 }
 98                 repaint();
 99                 i++;
100             }
101         }, 0, 1000);
102 
103     }
104 
105     /*
106      * Title: paintComponent
107      * Description: 重写绘制内容函数，利用switch选取显示内容（遮挡方式）
108      * @param g 
109      * @see javax.swing.JComponent#paintComponent(java.awt.Graphics) 
110      */
111     protected void paintComponent(Graphics g) {
112 
113         super.paintComponent(g);
114 
115         g.setColor(Color.RED);
116         g.fillOval(redX, ballY, ballWidth, ballWidth);
117         g.setColor(Color.YELLOW);
118         g.fillOval(yellowX, ballY, ballWidth, ballWidth);
119         g.setColor(Color.GREEN);
120         g.fillOval(greenX, ballY, ballWidth, ballWidth);
121         g.setColor(this.getBackground());
122         switch (color) {
123         case RED:
124             g.fillRect(yellowX, ballY, greenX - yellowX + ballWidth, ballWidth);
125             g.setColor(Color.BLACK);
126             g.drawOval(yellowX, ballY, ballWidth, ballWidth);
127             g.drawOval(greenX, ballY, ballWidth, ballWidth);
128             break;
129         case YELLOW:
130             g.fillRect(redX, ballY, ballWidth, ballWidth);
131             g.fillRect(greenX, ballY, ballWidth, ballWidth);
132             g.setColor(Color.BLACK);
133             g.drawOval(redX, ballY, ballWidth, ballWidth);
134             g.drawOval(greenX, ballY, ballWidth, ballWidth);
135             break;
136         case GREEN:
137             g.fillRect(redX, ballY, yellowX - redX + ballWidth, ballWidth);
138             g.setColor(Color.BLACK);
139             g.drawOval(redX, ballY, ballWidth, ballWidth);
140             g.drawOval(yellowX, ballY, ballWidth, ballWidth);
141             break;
142         case BLANK:
143             g.fillRect(redX, ballY, greenX - redX + ballWidth, ballWidth);
144             g.setColor(Color.BLACK);
145             g.drawOval(redX, ballY, ballWidth, ballWidth);
146             g.drawOval(yellowX, ballY, ballWidth, ballWidth);
147             g.drawOval(greenX, ballY, ballWidth, ballWidth);
148         default:
149             break;
150         }
151     }
152 
153     public static void main(String[] args) {
154         JPanel p = new TrafficLights();
155         JFrame frame = new JFrame("交通灯");
156         frame.getContentPane().add(p);
157         frame.setSize(winWidth, winHeight);
158         frame.setLocation(500, 200);
159         frame.setVisible(true);
160         frame.setResizable(false);
161         ((TrafficLights) p).changeLights(5, 5, 5);
162     }
163 }
道阻且长，行则将至。
【 Java 】 简易交通灯

【 Java 】简易交通灯
