工厂方法模式设计畜牧场（Java代码实例）

有很多种类的畜牧场，如养马场用于养马，养牛场用于养牛，所以该实例用工厂方法模式比较适合。

package FactoryMethod;
import java.awt.*;
import javax.swing.*;
public class AnimalFarmTest {
    public static void main(String[] args) {
        try {
            Animal a;
            AnimalFarm af;
            af = (AnimalFarm) ReadXML2.getObject();
            a = af.newAnimal();
            a.show();
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
}

//抽象产品：动物类
interface Animal {
    public void show();
}

//具体产品：马类
class Horse implements Animal {
    JScrollPane sp;
    JFrame jf = new JFrame("工厂方法模式测试");

    public Horse() {
        Container contentPane = jf.getContentPane();
        JPanel p1 = new JPanel();
        p1.setLayout(new GridLayout(1, 1));
        p1.setBorder(BorderFactory.createTitledBorder("动物：马"));
        sp = new JScrollPane(p1);
        contentPane.add(sp, BorderLayout.CENTER);
        JLabel l1 = new JLabel(new ImageIcon("src/A_Horse.jpg"));
        p1.add(l1);
        jf.pack();
        jf.setVisible(false);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);    //用户点击窗口关闭
    }
    public void show() {
        jf.setVisible(true);
    }
}

//具体产品：牛类
class Cattle implements Animal {
    JScrollPane sp;
    JFrame jf = new JFrame("工厂方法模式测试");

    public Cattle() {
        Container contentPane = jf.getContentPane();
        JPanel p1 = new JPanel();
        p1.setLayout(new GridLayout(1, 1));
        p1.setBorder(BorderFactory.createTitledBorder("动物：牛"));
        sp = new JScrollPane(p1);
        contentPane.add(sp, BorderLayout.CENTER);
        JLabel l1 = new JLabel(new ImageIcon("src/A_Cattle.jpg"));
        p1.add(l1);
        jf.pack();
        jf.setVisible(false);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);    //用户点击窗口关闭
    }
    public void show() {
        jf.setVisible(true);
    }
}

//抽象工厂：畜牧场
interface AnimalFarm {
    public Animal newAnimal();
}

//具体工厂：养马场
class HorseFarm implements AnimalFarm {
    public Animal newAnimal() {
        System.out.println("新马出生！");
        return new Horse();
    }
}

//具体工厂：养牛场
class CattleFarm implements AnimalFarm {
    public Animal newAnimal() {
        System.out.println("新牛出生！");
        return new Cattle();
    }
}

package FactoryMethod;
import javax.xml.parsers.*;
import org.w3c.dom.*;
import java.io.*;
class ReadXML2 {
    public static Object getObject() {
        try {
            DocumentBuilderFactory dFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = dFactory.newDocumentBuilder();
            Document doc;
            doc = builder.parse(new File("src/FactoryMethod/config2.xml"));
            NodeList nl = doc.getElementsByTagName("className");
            Node classNode = nl.item(0).getFirstChild();
            String cName = "FactoryMethod." + classNode.getNodeValue();
            System.out.println("新类名：" + cName);
            Class<?> c = Class.forName(cName);
            Object obj = c.newInstance();
            return obj;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
}