trypolyline.java

来自「Java Classic Examples是我买的两本书：《JAVA经典实例》和」· Java 代码 · 共 80 行

import java.io.*;

public class TryPolyLine
{
  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.} };

    // Create a polyline from the coordinates and display it
    PolyLine polygon = new PolyLine(coords);
    System.out.println(polygon);

    // Add a point and display the polyline again
    polygon.addPoint(10., 10.);
    System.out.println(polygon);

    // Create Point objects from the coordinate array
    Point[] points = new Point[coords.length];
    for(int i = 0; i < points.length; i++)
      points[i] = new Point(coords[i][0],coords[i][1]);

    // Use the points to create a new polyline and display it
    PolyLine newPoly = new PolyLine(points);
    System.out.println(newPoly);

    // Write both polyline objects to the file
    try
    {
      // Create the object output stream
      ObjectOutputStream objectOut = 
                    new ObjectOutputStream(
                    new BufferedOutputStream(
                    new FileOutputStream("c:\\JunkData\\Polygons.bin")));

      objectOut.writeObject(polygon);            // Write first object
      objectOut.writeObject(newPoly);            // Write second object
      objectOut.close();                         // Close the output stream
    }
    catch(NotSerializableException e)
    {
      System.err.println(e);
    }
    catch(InvalidClassException e)
    {
      System.err.println(e);
    }
    catch(IOException e)
    {
      System.err.println(e);
    }

    // Read the objects back from the file

    System.out.println("\nReading objects from the file: ");
    try
    {
      ObjectInputStream objectIn = 
                     new ObjectInputStream(
                     new BufferedInputStream(
                     new FileInputStream("c:\\JunkData\\Polygons.bin")));

      PolyLine theLine = (PolyLine)objectIn.readObject();
      System.out.println(theLine);               // Display the first object
      theLine = (PolyLine)objectIn.readObject();
      System.out.println(theLine);               // Display the second object
      objectIn.close();                          // Close the input stream
    }
    catch(IOException e)
    {
      System.err.println(e);
    }
    catch(ClassNotFoundException e)
    {
      System.err.println(e);
    }
  }
}