67 lines
1.5 KiB
Java
67 lines
1.5 KiB
Java
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//: patterns/factory/ShapeFactory1.java
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// A simple static factory method.
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package patterns.factory;
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import java.util.*;
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class BadShapeCreation extends Exception {
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BadShapeCreation(String msg) {
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super(msg);
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}
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}
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abstract class Shape {
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public abstract void draw();
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public abstract void erase();
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static Shape factory(String type)
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throws BadShapeCreation {
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if(type == "Circle") return new Circle();
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if(type == "Square") return new Square();
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throw new BadShapeCreation(type);
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}
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}
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class Circle extends Shape {
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Circle() {} // Friendly constructor
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@Override
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public void draw() {
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System.out.println("Circle.draw");
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}
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@Override
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public void erase() {
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System.out.println("Circle.erase");
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}
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}
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class Square extends Shape {
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Square() {} // Friendly constructor
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@Override
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public void draw() {
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System.out.println("Square.draw");
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}
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@Override
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public void erase() {
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System.out.println("Square.erase");
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}
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}
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public class ShapeFactory1 {
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public static void main(String args[]) {
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String shlist[] = { "Circle", "Square",
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"Square", "Circle", "Circle", "Square" };
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ArrayList shapes = new ArrayList();
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try {
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for(int i = 0; i < shlist.length; i++)
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shapes.add(Shape.factory(shlist[i]));
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} catch(BadShapeCreation e) {
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e.printStackTrace();
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return;
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}
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Iterator i = shapes.iterator();
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while(i.hasNext()) {
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Shape s = (Shape)i.next();
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s.draw();
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s.erase();
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}
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}
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} ///:~
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