根据以下要求：Instead of using a binary file to save the arraylist of points, change the sava
Data method and the constructor of the Model class to use a
database to write / read the coordinates of all the points. Use XAMPP and phpMyAdmin to create a
database called "java" with a table called "points" that has two integer columns x and y (in addition to the ID primary key). Hint: make sure you
delete all the old point coordinates
from the
database before inserting new ones. Hint: use phpMyAdmin to check what is stored in the
database. Use the
Test class to run all the
tests for the software and check that all the
tests still work. Use the Start class to run the software and check that closing the software correctly saves the point coordinates in the
database (use phpMyAdmin to check the content of the
database). Run the software again and check that all the points
from the previous run are correctly displayed，修改下述代码：public class Model implements Serializable { private ArrayList<Point> points; private ArrayList<ModelListener> listeners; private static final String FILE_NAME = "points.bin"; public Model() { points = new ArrayList<Point>(); listeners = new ArrayList<ModelListener>(); // Read points
from file if it exists File file = new File(FILE_NAME); if (file.exists()) { try { ObjectInputStream in = new ObjectInputStream(new FileInputStream(file)); points = (ArrayList<Point>) in.readObject(); in.close(); } catch (IOException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } } } public void addListener(ModelListener l) { listeners.add(l); } public ArrayList<Point> getPoints() { return points; } public void addPoint(Point p) { points.add(p); notifyListeners(); // points changed so notify the listeners. save
Data(); // save point to file } public void
clearAllPoints() { points.
clear(); notifyListeners(); // points changed so notify the listeners. save
Data(); // save empty list to file } public void
deleteLastPoint() { if (points.size() > 0) { points.remove(points.size() - 1); notifyListeners(); // points changed so notify the listeners. save
Data(); // save updated list to file } } private void notifyListeners() { for (ModelListener l : listeners) { l.update(); // Tell the listener that something changed. } } public int numberOfPoints() { return points.size(); } public void save
Data() { try { ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(FILE_NAME)); out.writeObject(points); out.close(); } catch (IOException e) { e.printStackTrace(); } }
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