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| 1 | +package structural; |
| 2 | + |
| 3 | +/** |
| 4 | + * Created by 李恒名 on 2017/7/27. |
| 5 | + * <p> |
| 6 | + * 装饰者模式 |
| 7 | + * |
| 8 | + * @see java.io.InputStream 抽象构件 |
| 9 | + * @see java.io.FilterInputStream 抽象装饰类 |
| 10 | + * @see java.io.BufferedInputStream 具体的装饰类 |
| 11 | + * @see java.io.DataInputStream 具体的装饰类 |
| 12 | + */ |
| 13 | +public class DecoratorPattern { |
| 14 | + //抽象构件(Component) |
| 15 | + static abstract class Man { |
| 16 | + abstract void aboutMe(); |
| 17 | + } |
| 18 | + |
| 19 | + //具体的构件(ConcreteComponent) |
| 20 | + static class Potato extends Man { |
| 21 | + |
| 22 | + @Override |
| 23 | + public void aboutMe() { |
| 24 | + System.out.print("Hi,我是土豆"); |
| 25 | + } |
| 26 | + } |
| 27 | + |
| 28 | + //抽象装饰类(Decorator) |
| 29 | + static abstract class Decorator extends Man { |
| 30 | + private Man man; |
| 31 | + |
| 32 | + protected Decorator(Man man) { |
| 33 | + this.man = man; |
| 34 | + } |
| 35 | + |
| 36 | + @Override |
| 37 | + public void aboutMe() { |
| 38 | + man.aboutMe(); |
| 39 | + } |
| 40 | + } |
| 41 | + |
| 42 | + //具体装饰类(ConcreteDecorator) |
| 43 | + static class ProgrammerDecorator extends Decorator { |
| 44 | + public ProgrammerDecorator(Man man) { |
| 45 | + super(man); |
| 46 | + } |
| 47 | + |
| 48 | + @Override |
| 49 | + public void aboutMe() { |
| 50 | + super.aboutMe(); |
| 51 | + System.out.print(",我的职业是程序员"); |
| 52 | + } |
| 53 | + } |
| 54 | + |
| 55 | + //具体装饰类(ConcreteDecorator) |
| 56 | + static class ReaderDecorator extends Decorator { |
| 57 | + public ReaderDecorator(Man man) { |
| 58 | + super(man); |
| 59 | + } |
| 60 | + |
| 61 | + @Override |
| 62 | + public void aboutMe() { |
| 63 | + super.aboutMe(); |
| 64 | + System.out.print(",我喜欢读书"); |
| 65 | + |
| 66 | + } |
| 67 | + } |
| 68 | + |
| 69 | + //具体装饰类(ConcreteDecorator) |
| 70 | + static class GitHubDecorator extends Decorator { |
| 71 | + public GitHubDecorator(Man man) { |
| 72 | + super(man); |
| 73 | + } |
| 74 | + |
| 75 | + @Override |
| 76 | + public void aboutMe() { |
| 77 | + super.aboutMe(); |
| 78 | + System.out.print(",闲暇时我喜欢在 GitHub 上溜达"); |
| 79 | + |
| 80 | + } |
| 81 | + } |
| 82 | + |
| 83 | + //具体装饰类(ConcreteDecorator) |
| 84 | + static class WriterDecorator extends Decorator { |
| 85 | + public WriterDecorator(Man man) { |
| 86 | + super(man); |
| 87 | + } |
| 88 | + |
| 89 | + @Override |
| 90 | + public void aboutMe() { |
| 91 | + super.aboutMe(); |
| 92 | + System.out.print(",也会去写一些技术文章"); |
| 93 | + |
| 94 | + } |
| 95 | + } |
| 96 | + |
| 97 | + //具体装饰类(ConcreteDecorator) |
| 98 | + public static void main(String[] args) { |
| 99 | + Man potato = new Potato(); |
| 100 | + potato.aboutMe(); |
| 101 | + //Hi,我是土豆 |
| 102 | + |
| 103 | + System.out.println(); |
| 104 | + |
| 105 | + potato = new WriterDecorator(new GitHubDecorator(new ReaderDecorator(new ProgrammerDecorator(potato)))); |
| 106 | + potato.aboutMe(); |
| 107 | + //Hi,我是土豆,我的职业是程序员,我喜欢读书,闲暇时我喜欢在 GitHub 上溜达,也会去写一些技术文章 |
| 108 | + } |
| 109 | + |
| 110 | + /** |
| 111 | + * 总结: |
| 112 | + * 装饰者模式,可以动态地将责任附加到对象上,若要扩展功能,装饰者提供了比继承更加有 |
| 113 | + * 弹性的替代方案,有效的避免了类爆炸现象的产生。虽然装饰者模式能够动态将责任附加到 |
| 114 | + * 对象上,但是他会产生许多的细小对象,增加了系统的复杂度。java.io 包可谓是装饰者 |
| 115 | + * 模式的最佳实践。 |
| 116 | + */ |
| 117 | +} |
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