80 lines
1.7 KiB
Java
80 lines
1.7 KiB
Java
// patterns/factory/ShapeFactory1.java
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// (c)2016 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://OnJava8.com for more book information.
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// A simple static factory method
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// {java patterns.factory.ShapeFactory1}
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package patterns.factory;
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import java.util.*;
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import java.util.stream.*;
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class BadShapeCreation extends RuntimeException {
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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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switch(type) {
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case "Circle": return new Circle();
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case "Square": return new Square();
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default:
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throw new BadShapeCreation(type);
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}
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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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List<Shape> shapes = Stream.of(
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"Circle", "Square",
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"Square", "Circle",
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"Circle", "Square")
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.map(Shape::factory)
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.collect(Collectors.toList());
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shapes.forEach(Shape::draw);
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shapes.forEach(Shape::erase);
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}
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}
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/* Output:
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Circle.draw
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Square.draw
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Square.draw
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Circle.draw
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Circle.draw
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Square.draw
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Circle.erase
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Square.erase
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Square.erase
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Circle.erase
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Circle.erase
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Square.erase
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*/
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