23种经典设计模式的java实现_1_抽象工厂模式

抽象工厂模式的适用：
一个系统要独立于它的产品的创建、组合和表示时。
一个系统要由多个产品系列中的一个来配置时。
当你要强调一系列相关的产品对象的设计以便进行联合使用时。 
当你提供一个产品类库，而只想显示它们的接口而不是实现时。

示例说明：
有三种抽象的产品：墙、门、房间。
对这三种抽象产品有两组具体实现：卧室和起居室。
那么，我们的抽象工厂就可以根据客户的指令（即调用参数）去生产卧室和起居室的房间（墙和门包括在房间里）。

测试启动类：

package com.alex.designpattern.abstractfactory;

/** *//**
 * 抽象工厂模式
 * <p>
 * 提供一个创建一系列相关或相互依赖对象的接口，而无需指定它们具体的类。
 * 
 * @author <a href=" huqimailto:huqiyes@gmail.com">huqi</a>
 * @serialData 2007
 */
public class Test ...{

    public static void main(String[] args) throws Exception ...{
        // ----- Create Living Room
        Room myLivingRoom = AbstractRoomFactory.createRoom("LivingRoom");
        AbstractRoomFactory.showRoom(myLivingRoom);

        // ----- Create Bed Room
        Room myBedRoom = AbstractRoomFactory.createRoom("BedRoom");
        AbstractRoomFactory.showRoom(myBedRoom);
    }
}
抽象产品：

package com.alex.designpattern.abstractfactory;

/** *//**
 * The Abstract Class of Wall
 */
public interface Wall ...{
    public String getName();
}

package com.alex.designpattern.abstractfactory;

/** *//**
 * The Abstract Class of Door
 */
public interface Door ...{
    public String getName();
}

package com.alex.designpattern.abstractfactory;

/** *//**
 * The Abstract Class of Room
 */
public interface Room ...{

    public Wall getWall();

    public Door getDoor();
}
实际产品_1

package com.alex.designpattern.abstractfactory;

/** *//**
 * A concrete Room - Bed Room
 */
public class BedRoom implements Room ...{
    public BedRoom() ...{
        System.out.println("Initiated a bedroom.");
    }

    public Door getDoor() ...{
        return new BedRoomDoor();
    }

    public Wall getWall() ...{
        return new BedRoomWall();
    }
}

package com.alex.designpattern.abstractfactory;

/** *//**
 * A concrete Door for Bed Room
 */
public class BedRoomDoor implements Door ...{
    private String doorName;

    public BedRoomDoor() ...{
        doorName = "BedRoomDoor";
    }

    public String getName() ...{
        return doorName;
    }
}

package com.alex.designpattern.abstractfactory;

/** *//**
 * A concrete Wall for Bed Room
 */
public class BedRoomWall implements Wall ...{
    private String wallName;

    public BedRoomWall() ...{
        wallName = "BedRoomWall";
    }

    public String getName() ...{
        return wallName;
    }
}
实际产品_2

package com.alex.designpattern.abstractfactory;

/** *//**
 * A concrete Room - Living Room
 */
public class LivingRoom implements Room ...{
    public LivingRoom() ...{
        System.out.println("Initiated a livingroom.");
    }

    public Door getDoor() ...{
        return new LivingRoomDoor();
    }

    public Wall getWall() ...{
        return new LivingRoomWall();
    }
}

package com.alex.designpattern.abstractfactory;

/** *//**
 * A concrete Door for Living Room
 */
public class LivingRoomDoor implements Door ...{
    private String doorName;

    public LivingRoomDoor() ...{
        doorName = "LivingRoomDoor";
    }

    public String getName() ...{
        return doorName;
    }
}

package com.alex.designpattern.abstractfactory;

/** *//**
 * A concrete Wall for Living Room
 */
public class LivingRoomWall implements Wall ...{
    private String wallName;

    public LivingRoomWall() ...{
        wallName = "LivingRoomWall";
    }

    public String getName() ...{
        return wallName;
    }
}
最后，当然就是抽象工厂咯，不过要注意，这个抽象工厂的意思并不是这个“工厂”是抽象的，而是这个“工厂”加工的“产品”是来自于抽象的。

package com.alex.designpattern.abstractfactory;

/** *//**
 * A Room Maker to test our simple Room Abstract Factory.
 * 
 * @author <a href=" huqimailto:huqiyes@gmail.com">huqi</a>
 * @serialData 2007
 */
public abstract class AbstractRoomFactory ...{

    public static Room createRoom(String roomType) throws Exception ...{
        if (roomType.equals("LivingRoom")) ...{
            return new LivingRoom();
        } else if (roomType.equals("BedRoom")) ...{
            return new BedRoom();
        } else ...{
            throw new Exception("No this type room: " + roomType);
        }
    }

    public static void showRoom(Room room) ...{
        Door door = room.getDoor();
        System.out.println("Room door name is: " + door.getName());
        Wall wall = room.getWall();
        System.out.println("Room wall name is: " + wall.getName());
    }
}