Java设计模式学习之抽象工厂模式

抽象工厂模式是创造型模式的一种，他和工厂模式类似，可以看作是工厂的工厂

工厂模式中使用一堆 if-else结构来返回客户端要的子类实例。抽象工厂模式不是用if-else，而是使用不同子类的工厂代理来返回子类实例

下面例子对之前工厂模式进行适当的修改,增加生成PC的PCFactory, 生成Server的ServerFactory
,以及修改ComputerFactory

PCFactory.java

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package com.walterlife.dp.FactoryDP;

public class PCFactory implements ComputerAbstractFactory {
    private String ram;
    private String hdd;
    private String cpu;

    public PCFactory(String ram, String hdd, String cpu) {
        this.ram = ram;
        this.hdd = hdd;
        this.cpu = cpu;
    }

    @Override
    public Computer createComputer() {
        return new PC(ram, hdd, cpu);
    }
}

ServerFactory.java

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package com.walterlife.dp.FactoryDP;

public class ServerFactory implements ComputerAbstractFactory {
    private String ram;
    private String hdd;
    private String cpu;

    public ServerFactory(String ram, String hdd, String cpu) {
        this.ram = ram;
        this.hdd = hdd;
        this.cpu = cpu;
    }

    @Override
    public Computer createComputer() {
        return new Server(ram, hdd, cpu);
    }
}

ComputerAbstractFactory.java

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package com.walterlife.dp.FactoryDP;

public interface ComputerAbstractFactory {
    public Computer createComputer();
}

ComputerFactory.java

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package  com.walterlife.dp.FactoryDP;

import org.apache.log4j.Logger;

public class ComputerFactory {
    static Logger logger = Logger.getLogger(ComputerFactory.class);

    public static Computer getComputer(ComputerAbstractFactory factory) {
        return factory.createComputer();
    } 
}

测试抽象工厂代码

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public static void testFactoryDP() {
    Computer pc = ComputerFactory.getComputer(new PCFactory("2GB", "500GB", 
                "2.4 GHz"));
    Computer server = ComputerFactory.getComputer(new ServerFactory("16GB", "1TB", "4 GHz"));

    if(pc != null) {
        logger.info("PC config :" + pc.toString());
    } else {
        logger.warn("PC instace is null!!!");
    } 

    if(server != null) {
        logger.info("Server config :" + server.toString());
    } else {
        logger.warn("Server instace is null!!!");
    } 
}

运行结果

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2015-08-23 18:14:06 INFO  com.walterlife.dp.App testFactoryDP:26 -> PC config :RAM: 2.GB HDD: 500GB CPU: 2.4 GHz
2015-08-23 18:14:06 INFO  com.walterlife.dp.App testFactoryDP:32 -> Server config :RAM: 16GB HDD: 1TB CPU: 4 GHz

留言

Jul 7 2015
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