Abstract Factory Design Pattern

package com.sheting.design.pattern.demo2;

public abstract class Computer {

    public abstract String getRAM();

    public abstract String getHDD();

    public abstract String getCPU();

    @Override
    public String toString() {
        return "RAM= " + this.getRAM() + ", HDD=" + this.getHDD() + ", CPU=" + this.getCPU();
    }

}

package com.sheting.design.pattern.demo2;

public class PC extends Computer {

    private String ram;
    private String hdd;
    private String cpu;

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

    @Override
    public String getRAM() {
        return this.ram;
    }

    @Override
    public String getHDD() {
        return this.hdd;
    }

    @Override
    public String getCPU() {
        return this.cpu;
    }

}

package com.sheting.design.pattern.demo2;

public class Server extends Computer {

    private String ram;
    private String hdd;
    private String cpu;

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

    @Override
    public String getRAM() {
        return this.ram;
    }

    @Override
    public String getHDD() {
        return this.hdd;
    }

    @Override
    public String getCPU() {
        return this.cpu;
    }

}

package com.sheting.design.pattern.demo2;

public interface ComputerAbstractFactory {

    Computer createComputer();
}

package com.sheting.design.pattern.demo2;

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);
    }

}

package com.sheting.design.pattern.demo2;

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);
    }

}

package com.sheting.design.pattern.demo2;

public class ComputerFactory {

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

}

package com.sheting.design.pattern.demo2;

public class TestDesignPatterns {

    public static void main(String[] args) {
        testAbstractFactory();
    }

    private static void testAbstractFactory() {
        Computer pc = ComputerFactory.getComputer(new PCFactory("2 GB", "500 GB", "2.4 GHz"));
        Computer server = ComputerFactory.getComputer(new ServerFactory("16 GB", "1 TB", "2.9 GHz"));
        System.out.println("AbstractFactory PC Config::" + pc);
        System.out.println("AbstractFactory Server Config::" + server);
    }

}

抽象工厂设计模式在JDK中使用例子

• javax.xml.parsers.DocumentBuilderFactory#newInstance()
• javax.xml.transform.TransformerFactory#newInstance()
• javax.xml.xpath.XPathFactory#newInstance()