FileDocCategorySizeDatePackage
CADSystem.javaAPI DocExample4082Mon Apr 06 18:10:24 BST 1998None

CADSystem.java

//: CADSystem.java
//////////////////////////////////////////////////
// Copyright (c) Bruce Eckel, 1998
// Source code file from the book "Thinking in Java"
// All rights reserved EXCEPT as allowed by the
// following statements: You can freely use this file
// for your own work (personal or commercial),
// including modifications and distribution in
// executable form only. Permission is granted to use
// this file in classroom situations, including its
// use in presentation materials, as long as the book
// "Thinking in Java" is cited as the source. 
// Except in classroom situations, you cannot copy
// and distribute this code; instead, the sole
// distribution point is http://www.BruceEckel.com 
// (and official mirror sites) where it is
// freely available. You cannot remove this
// copyright and notice. You cannot distribute
// modified versions of the source code in this
// package. You cannot use this file in printed
// media without the express permission of the
// author. Bruce Eckel makes no representation about
// the suitability of this software for any purpose.
// It is provided "as is" without express or implied
// warranty of any kind, including any implied
// warranty of merchantability, fitness for a
// particular purpose or non-infringement. The entire
// risk as to the quality and performance of the
// software is with you. Bruce Eckel and the
// publisher shall not be liable for any damages
// suffered by you or any third party as a result of
// using or distributing software. In no event will
// Bruce Eckel or the publisher be liable for any
// lost revenue, profit, or data, or for direct,
// indirect, special, consequential, incidental, or
// punitive damages, however caused and regardless of
// the theory of liability, arising out of the use of
// or inability to use software, even if Bruce Eckel
// and the publisher have been advised of the
// possibility of such damages. Should the software
// prove defective, you assume the cost of all
// necessary servicing, repair, or correction. If you
// think you've found an error, please email all
// modified files with clearly commented changes to:
// Bruce@EckelObjects.com. (Please use the same
// address for non-code errors found in the book.)
/////////////////////////////////////////////////

// Ensuring proper cleanup
import java.util.*;

class Shape {
  Shape(int i) {
    System.out.println("Shape constructor");
  }
  void cleanup() {
    System.out.println("Shape cleanup");
  }
}

class Circle extends Shape {
  Circle(int i) {
    super(i);
    System.out.println("Drawing a Circle");
  }
  void cleanup() {
    System.out.println("Erasing a Circle");
    super.cleanup();
  }
}

class Triangle extends Shape {
  Triangle(int i) {
    super(i);
    System.out.println("Drawing a Triangle");
  }
  void cleanup() {
    System.out.println("Erasing a Triangle");
    super.cleanup();
  }
}

class Line extends Shape {
  private int start, end;
  Line(int start, int end) {
    super(start);
    this.start = start;
    this.end = end;
    System.out.println("Drawing a Line: " +
           start + ", " + end);
  }
  void cleanup() {
    System.out.println("Erasing a Line: " +
           start + ", " + end);
    super.cleanup();
  }
}

public class CADSystem extends Shape {
  private Circle c;
  private Triangle t;
  private Line[] lines = new Line[10];
  CADSystem(int i) {
    super(i + 1);
    for(int j = 0; j < 10; j++)
      lines[j] = new Line(j, j*j);
    c = new Circle(1);
    t = new Triangle(1);
    System.out.println("Combined constructor");
  }
  void cleanup() {
    System.out.println("CADSystem.cleanup()");
    t.cleanup();
    c.cleanup();
    for(int i = 0; i < lines.length; i++)
      lines[i].cleanup();
    super.cleanup();
  }
  public static void main(String[] args) {
    CADSystem x = new CADSystem(47);
    try {
      // Code and exception handling...
    } finally {
      x.cleanup();
    }
  }
} ///:~