import java.io.*;
import java.nio.file.*;

public class TryPolyLineObjects {
  public static void main(String[] args) {
    // Create an array of coordinate pairs
    double[][] coords = { {1., 1.}, {1., 2.}, { 2., 3.},
                          {-3., 5.}, {-5., 1.}, {0., 0.} };

    Path file = Paths.get(System.getProperty("user.home")).resolve("Beginning Java Stuff").resolve("Polygons.bin");
    try {
      Files.createDirectories(file.getParent()); // Make sure we have directory
    } catch (IOException e) {
      e.printStackTrace();
      System.exit(1);
    }

    // Create the polyline objects and write them to the file
    System.out.println("Writing objects to file.");
    try (ObjectOutputStream objectOut = new ObjectOutputStream(new BufferedOutputStream(Files.newOutputStream(file)))){

      // Create a polyline from the coordinates
      PolyLine polygon1 = new PolyLine(coords);
      System.out.println(polygon1);
      objectOut.writeObject(polygon1);                                 // Write first object

      PolyLine polygon2 = new PolyLine(coords);
      polygon2.addPoint(10., 10.);
      System.out.println(polygon2);                                    // Add a point
      objectOut.writeObject(polygon2);                                 // Write second object

      PolyLine polygon3 = new PolyLine(coords);
      polygon3.addPoint(10., 15.);
      System.out.println(polygon3);                                    // Add a point
      objectOut.writeObject(polygon3);                                 // Write third object
      System.out.println("File written.");
    } catch(IOException e) {
      e.printStackTrace();
      System.exit(1);
    }

    // Read the objects back from the file
    PolyLine polylines[] = new PolyLine[3];
    System.out.println("\nReading objects from the file:");
    try (ObjectInputStream objectIn = new ObjectInputStream(new BufferedInputStream(Files.newInputStream(file)))){
      for(int i = 0 ; i < polylines.length ; ++i) {
        polylines[i] = (PolyLine)objectIn.readObject();
      }
    } catch(ClassNotFoundException  e) {
      System.err.println("Class not found.");
      e.printStackTrace();
    } catch(IOException e){
      e.printStackTrace();
    }
    // Display the objects read from the file
    for(int i = 0 ; i < polylines.length ; ++i) {
      System.out.println(polylines[i]);
    }
  }
}