设计模式 - 结构型模式 - 装饰模式

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//抽象界面构件类：抽象构件类，为了突出与模式相关的核心代码，对原有控件代码进行了大量的简化abstract class Component {    public abstract void display();}//窗体类：具体构件类class Window extends Component {    public void display() {        System.out.println("显示窗体！");    }}//文本框类：具体构件类class TextBox extends Component {    public void display() {        System.out.println("显示文本框！");    }}//列表框类：具体构件类class ListBox extends Component {    public void display() {        System.out.println("显示列表框！");    }}//构件装饰类：抽象装饰类class ComponentDecorator extends Component {    private Component component; //维持对抽象构件类型对象的引用    public ComponentDecorator(Component component) //注入抽象构件类型的对象    {        this.component = component;    }    public void display() {        component.display();    }}//滚动条装饰类：具体装饰类class ScrollBarDecorator extends ComponentDecorator {    public ScrollBarDecorator(Component component) {        super(component);    }    public void display()    {        this.setScrollBar();        super.display();    }    public void setScrollBar() {        System.out.println("为构件增加滚动条！");    }}//黑色边框装饰类：具体装饰类class BlackBorderDecorator extends ComponentDecorator {    public BlackBorderDecorator(Component component) {        super(component);    }    public void display() {        this.setBlackBorder();        super.display();    }    public void setBlackBorder() {        System.out.println("为构件增加黑色边框！");    }}class Client {    public static void main(String args[]) {        Component component, componentSB; //使用抽象构件定义        component = new Window(); //定义具体构件        componentSB = new ScrollBarDecorator(component); //定义装饰后的构件        componentSB.display();    }}