设计模式

单例模式

package com.designpattern;

public class SingletonDemo {
    private static volatile SingletonDemo singleton;
    private SingletonDemo(){}

    private static SingletonDemo getInstance() {
        if (singleton == null) {
            synchronized (SingletonDemo.class) {
                if (singleton == null) {
                    singleton = new SingletonDemo();
                }
            }
        }
        return singleton;
    }
}

简单工厂模式

package com.designpattern;

/**
 * 简单工厂模式
 *
 * 抽象Product、Product类、工厂类、
 *
 */
abstract class Phone{
    public abstract void sing();
}

class MiPhone extends Phone {

    @Override
    public void sing() {
        System.out.println("xiaomi");
    }
}

class IPhone extends Phone {
    @Override
    public void sing(){
        System.out.println("Iphone");
    }
}

class PhoneFactory{
    public Phone make(String kind){
        if(kind.equalsIgnoreCase("xiaOmI")){
            return new MiPhone();
        }else if(kind.equalsIgnoreCase("iphOne")){
            return new IPhone();
        }
        return null;
    }
}

public class SimpleFactoryDemo {
    public static void main(String[] args) {
        PhoneFactory pf = new PhoneFactory();
        Phone phone = pf.make("xiaoMI");
        phone.sing();

    }
}

工厂方法模式

package com.designpattern;

/**
 * 工厂方法模式
 *
 * 抽象目标类、具体目标类、工厂接口
 * 
 */
//abstract class Phone{
//    public abstract void sing();
//}
//
//class MiPhone extends Phone {
//    @Override
//    public void sing() {
//        System.out.println("xiaomi");
//    }
//}
//
//class IPhone extends Phone {
//
//    @Override
//    public void sing() {
//        System.out.println("iphone");
//    }
//}

interface IFactory{
    Phone makePhone();
}

class MiFactory implements IFactory{
    @Override
    public Phone makePhone() {
        return new MiPhone();
    }
}

class IPhoneFactory implements IFactory {

    @Override
    public Phone makePhone() {
        return new IPhone();
    }
}

public class FactoryMethodDemo {
    public static void main(String[] args) {
        IFactory miFactory = new MiFactory();
        IFactory iphoneFactory = new IPhoneFactory();
        Phone miPhone = miFactory.makePhone();
        Phone iPhone = iphoneFactory.makePhone();
        miPhone.sing();
        iPhone.sing();

    }
}