向上转型

• 向上转型。去if、else，面向业务内容，优雅的将平面逻辑立体化。

package upperConvert;

public class UpperConvert {

    /**
     * 向上转型
     */
    public static void main(String[] args) {
        UpperConvert.run(new LCDMonitor());
        UpperConvert.run(new CRTMonitor());
        UpperConvert.run(new PlasmaMonitor());
    }

    public static void run(Monitor monitor) {
        monitor.displayText();
        monitor.displayGraphics();
    }

}

class Monitor {
    public void displayText() {
    }

    public void displayGraphics() {
    }
}

class LCDMonitor extends Monitor {
    public void displayText() {
        System.out.println("LCD display text");
    }

    public void displayGraphics() {
        System.out.println("LCD display graphics");
    }
}

class CRTMonitor extends Monitor {
    public void displayText() {
        System.out.println("CRT display text");
    }

    public void displayGraphics() {
        System.out.println("CRT display graphics");
    }
}

class PlasmaMonitor extends Monitor {
    public void displayText() {
        System.out.println("Plasma display text");
    }

    public void displayGraphics() {
        System.out.println("Plasma display graphics");
    }
}

 源码地址：http://files.cnblogs.com/files/xiluhua/UpperConvert.rar