Java丨Ele实验室“疫情传播仿真程序”的代码实现

小编说：本文由博文视点一位身在武汉的作者龙中华老师，根据Ele实验室发布的“疫情传播仿真程序”视频以及其开源代码整理编辑而成*，*首发于个人博客：
https://blog.csdn.net/u013840066/article/details/104212919

前几天，“Ele实验室” Bruce Young同学在家制作了一个有关病毒传播的仿真程序（https://www.bilibili.com/video/av86478875），为我们带来了极大的视角上的震撼，对于人们认识病毒传播有很大的价值，于是这里把源代码分享出来（版权归Bruce Young同学），因为该程序实际上没有实际的商用价值（有很大的传播教育价值），所以我们只做一些简单的讲解。

视频中程序代码GitHub开源链接：

https://github.com/KikiLetGo/VirusBroadcast/tree/master/src

下面我们进入正题，运行效果图如下图所示：

该程序主要使用Swing（一个为Java设计的GUI工具包）来绘制图形用户界面（GUI）。实现的步骤如下：

创建Point 类

该类用于定义绘制图形界面上的点，代码如下：

public class Point { private int x; private int y; public Point(int x, int y) { this.x = x; this.y = y; } public int getX() {return x;}public void setX(int x) {this.x = x;}public int getY() {return y;}public void setY(int y) {this.y = y;}}

创建常量类

该类用于调整参数来展现不同的效果，见下方代码：

public class Constants { //初始感染数量 public static int ORIGINAL_COUNT=50; //传播率 public static float BROAD_RATE = 0.8f; //潜伏时间 public static float SHADOW_TIME = 140; //医院收治响应时间 9    public static int HOSPITAL_RECEIVE_TIME=10;//医院床位public static int BED_COUNT=1000;//流动意向平均值public static float u=-0.99f;14}

创建城市类

该类用于定义一个城市。

  public class City { private int centerX; private int centerY; public City(int centerX, int centerY) { this.centerX = centerX; this.centerY = centerY; } public int getCenterX() {return centerX;}public void setCenterX(int centerX) {this.centerX = centerX;}public int getCenterY() {return centerY;}public void setCenterY(int centerY) {this.centerY = centerY;}}

创建医院类

该类用于创建一个演示的医院类。

  public class Hospital { private int x=800; private int y=110; private int width; private int height=606; public int getWidth() { return width; } public int getHeight() {return height;}public int getX() {return x;}public int getY() {return y;}private static Hospital hospital = new Hospital();public static Hospital getInstance(){return hospital;}private Point point = new Point(800,100);private List<Bed> beds = new ArrayList<>();private Hospital() {if(Constants.BED_COUNT==0){width=0;height=0;}int column = Constants.BED_COUNT/100;width = column*6;for(int i=0;i<column;i  ){for(int j=10;j<=610;j =6){Bed bed = new Bed(point.getX() i*6,point.getY() j);beds.add(bed);}}}public Bed pickBed(){for(Bed bed:beds){if(bed.isEmpty()){return bed;}}return null;}}

创建医院的床位类

该类创建一个用于演示的医院的病床类。

  public class Bed extends Point{public Bed(int x, int y) { super(x, y); } private boolean isEmpty=true; public boolean isEmpty() { return isEmpty; }public void setEmpty(boolean empty) {isEmpty = empty;}}

创建PersonPool类

该类创建PersonPool，用于管理城市大小和人数。

  public class PersonPool { private static PersonPool personPool = new PersonPool(); public static PersonPool getInstance(){ return personPool; } List<Person> personList = new ArrayList<Person>(); public List<Person> getPersonList() {return personList;}private PersonPool() {City city = new City(400,400);for (int i = 0; i < 5000; i  ) {Random random = new Random();int x = (int) (100 * random.nextGaussian()   city.getCenterX());int y = (int) (100 * random.nextGaussian()   city.getCenterY());if(x>700){x=700;}Person person = new Person(city,x,y);personList.add(person);}}}

创建Person类

  public class Person {  private City city;  private int x;  private int y;  private MoveTarget moveTarget;  int sig=1;  double targetXU; double targetYU; double targetSig=50; public interface State{ int NORMAL = 0; int SUSPECTED = NORMAL 1; int SHADOW = SUSPECTED 1; int CONFIRMED = SHADOW 1; int FREEZE = CONFIRMED 1; int CURED = FREEZE 1; } public Person(City city, int x, int y) { this.city = city; this.x = x; this.y = y; targetXU = 100*new Random().nextGaussian() x;targetYU = 100*new Random().nextGaussian() y; } public boolean wantMove(){         double value = sig*new Random().nextGaussian() Constants.u; return value>0; } private int state=State.NORMAL; public int getState() { return state; } public void setState(int state) { this.state = state; } public int getX() { return x; } public void setX(int x) { this.x = x; } public int getY() { return y; } public void setY(int y) { this.y = y; } int infectedTime=0; int confirmedTime=0; public boolean isInfected(){ return state>=State.SHADOW; } public void beInfected(){ state = State.SHADOW; infectedTime=MyPanel.worldTime; } public double distance(Person person){ return Math.sqrt(Math.pow(x-person.getX(),2) Math.pow(y-person.getY(),2)); } private void freezy(){ state = State.FREEZE; } private void moveTo(int x,int y){ this.x =x; this.y =y; } private void action(){ if(state==State.FREEZE){ return; } if(!wantMove()){ return; } if(moveTarget==null||moveTarget.isArrived()){ double targetX = targetSig*new Random().nextGaussian() targetXU;             double targetY = targetSig*new Random().nextGaussian() targetYU; moveTarget = new MoveTarget((int)targetX,(int)targetY); } int dX = moveTarget.getX()-x;int dY = moveTarget.getY()-y;double length=Math.sqrt(Math.pow(dX,2) Math.pow(dY,2));if(length<1){moveTarget.setArrived(true);return;}int udX = (int) (dX/length);if(udX==0&&dX!=0){if(dX>0){udX=1;}else{udX=-1;}}int udY = (int) (dY/length);if(udY==0&&udY!=0){if(dY>0){udY=1;}else{udY=-1;121            }}if(x>700){moveTarget=null;if(udX>0){udX=-udX;}}moveTo(udX,udY);//        if(wantMove()){//        }}private float SAFE_DIST = 2f;public void update(){//@TODO找时间改为状态机142        if(state>=State.FREEZE){return;}if(state==State.CONFIRMED&&MyPanel.worldTime-confirmedTime>=Constants.HOSPITAL_RECEIVE_TIME){Bed bed = Hospital.getInstance().pickBed();if(bed==null){System.out.println("隔离区没有空床位");}else{state=State.FREEZE;x=bed.getX();y=bed.getY();bed.setEmpty(false);}}if(MyPanel.worldTime-infectedTime>Constants.SHADOW_TIME&&state==State.SHADOW){state=State.CONFIRMED;confirmedTime = MyPanel.worldTime;}action();List<Person> people = PersonPool.getInstance().personList;if(state>=State.SHADOW){return;166        }for(Person person:people){if(person.getState()== State.NORMAL){continue;}float random = new Random().nextFloat();if(random<Constants.BROAD_RATE&&distance(person)<SAFE_DIST){this.beInfected();}}}}

创建MyPanel类

public class MyPanel extends JPanel implements Runnable { private int pIndex=0; public MyPanel() { this.setBackground(new Color(0x444444)); } @Overridepublic void paint(Graphics arg0) {super.paint(arg0);//draw borderarg0.setColor(new Color(0x00ff00));arg0.drawRect(Hospital.getInstance().getX(),Hospital.getInstance().getY(),Hospital.getInstance().getWidth(),Hospital.getInstance().getHeight());List<Person> people = PersonPool.getInstance().getPersonList();if(people==null){return;}people.get(pIndex).update();for(Person person:people){switch (person.getState()){case Person.State.NORMAL:{arg0.setColor(new Color(0xdddddd));}break;case Person.State.SHADOW:{arg0.setColor(new Color(0xffee00));}break;case Person.State.CONFIRMED:case Person.State.FREEZE:{arg0.setColor(new Color(0xff0000));}break;}person.update();arg0.fillOval(person.getX(), person.getY(), 3, 3);}pIndex  ;if(pIndex>=people.size()){pIndex=0;}}public static int worldTime=0;@Overridepublic void run() {while (true) {5657            this.repaint();5859            try {Thread.sleep(100);worldTime  ;} catch (InterruptedException e) {e.printStackTrace();}}}}

创建MoveTarget 类

创建MoveTarget 类用于模拟人群流动。

 public class MoveTarget { private int x; private int y; private boolean arrived=false; public MoveTarget(int x, int y) { this.x = x; this.y = y; }public int getX() {return x;}public void setX(int x) {this.x = x;17    }public int getY() {return y;}public void setY(int y) {this.y = y;}public boolean isArrived() {return arrived;}public void setArrived(boolean arrived) {this.arrived = arrived;}}

修改入口类

修改入口类，绘制图形

  import javax.swing.*; import java.awt.image.BufferedImage; import java.util.ArrayList; import java.util.List; import java.util.Random; public class Main { public static void main(String[] args) { MyPanel p = new MyPanel();Thread panelThread = new Thread(p);JFrame frame = new JFrame();frame.add(p);frame.setSize(1000, 800);frame.setLocationRelativeTo(null);frame.setVisible(true);frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);panelThread.start();List<Person> people = PersonPool.getInstance().getPersonList();for(int i=0;i<Constants.ORIGINAL_COUNT;i  ){int index = new Random().nextInt(people.size()-1);Person person = people.get(index);while (person.isInfected()){index = new Random().nextInt(people.size()-1);person = people.get(index);}person.beInfected();}}}

到此完成，运行程序即可。

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