用java编程，模拟红绿灯，红灯亮10s,绿灯亮10s,黄灯亮2S

在Java编程中，我们可以创建一个简单的模拟红绿灯的程序，使用计时器和循环结构来控制信号灯的变化。这里是一个基本的示例：

import java.util.Timer;
import java.util.TimerTask;

public class TrafficLight {
    private int trafficSignalStatus; // 0 - 红灯，1 - 黄灯，2 - 绿灯
    private static final int RED_LIGHT_SECONDS = 10;
    private static final int GREEN_LIGHT_SECONDS = 10;
    private static final int YELLOW_LIGHT_SECONDS = 2;

    public void startSimulation() {
        Timer timer = new Timer();
        timer.schedule(new ChangeTrafficLightTask(), 0, 12000); // 每隔12000毫秒（即20秒）切换一次信号灯状态
    }

    private class ChangeTrafficLightTask extends TimerTask {
        @Override
        public void run() {
            switch (trafficSignalStatus) {
                case 0: // 红灯
                    System.out.println("红灯亮起，倒数 " + RED_LIGHT_SECONDS);
                    trafficSignalStatus = 1;
                    break;
                case 1: // 黄灯
                    if (RED_LIGHT_SECONDS > 0) {
                        System.out.println("黄灯亮起，剩余 " + RED_LIGHT_SECONDS);
                    } else {
                        trafficSignalStatus = 2;
                        System.out.println("黄灯结束，转绿灯");
                    }
                    break;
                case 2: // 绿灯
                    System.out.println("绿灯亮起，倒数 " + GREEN_LIGHT_SECONDS);
                    trafficSignalStatus = 0; // 到达绿灯后，重新回到红灯阶段
                    break;
            }
            RED_LIGHT_SECONDS--;
            GREEN_LIGHT_SECONDS--;
        }
    }

    public static void main(String[] args) {
        TrafficLight trafficLight = new TrafficLight();
        trafficLight.startSimulation();
    }
}