完整案例分析再加知识整合——艾特工厂方法模式，超详细的

package factorymethod;

public interface TV {
    public void play();
}

package factorymethod;

public class HaierTV implements TV {
    @Override
    public void play() {
        System.out.println("海尔电视机播放中···");
    }
}

package factorymethod;

public class HisenseTV implements TV {
    @Override
    public void play() {
        System.out.println("海信电视机播放中···");
    }
}

package factorymethod;

public interface TVFactory {
    public TV produceTV();
}

package factorymethod;

public class HaierTVFactory implements TVFactory {
    @Override
    public TV produceTV() {
        System.out.println("海尔电视机工厂生产海尔电视机！");
        return new HaierTV();
    }
}

package factorymethod;

public class HisenseTVFactory implements TVFactory {
    @Override
    public TV produceTV() {
        System.out.println("海信电视机工厂生产海信电视机！");
        return new HisenseTV();
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<config>
    <className>factorymethod.HisenseTVFactory</className>

    <!--<className>factorymethod.HaierTVFactory</className>-->
</config>

package factorymethod;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.File;

public class XMLUtil {

    //该方法用于从XML配置文件中提取具体类类名，并返回一个实例对象
    public static Object getBean(){
        try {
            //创建文档对象
            DocumentBuilderFactory dFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = dFactory.newDocumentBuilder();
            Document doc;

            doc = builder.parse(new File("D:\\MyNewWorld\\Study_JAVA\\MyHome\\Write_java\\My_Maven\\src\\main\\resources\\FactoryMethodconfig.xml"));


            //获取包含类名的文本节点
            NodeList n1 = doc.getElementsByTagName("className");
            Node classNode = n1.item(0).getFirstChild();

            String cName = classNode.getNodeValue();

            //通过类名生成实例对象并将其返回
            Class c = Class.forName(cName);
            Object obj = c.newInstance();
            return obj;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
}

package factorymethod;

public class Client {
    public static void main(String[] args) {
        try {
            TV tv;
            TVFactory factory;
            factory = (TVFactory) XMLUtil.getBean();
            tv = factory.produceTV();
            tv.play();
        }catch (Exception e){
            System.out.println(e.getMessage());
        }
    }
}