在上一篇博客中我们使用了工厂模式来设计一个网上车辆交易系统。在那个样例中仅仅有汽车这一种单一类型的商品。那么，假设有多种类型的商品。还能用工厂方法模式吗？举个样例，如今有个网上服装买卖系统。有三种服装---鞋、套装和衬衫，当中又分为男鞋女鞋、男套装和女套装、男衬衫和女衬衫。即例如以下商品：
依照上节中说到的工厂方法模式，应该这样设计。使用三个工厂来创建三个对象：
这样做也能实现。可是工厂类有点多吧，并且在client中将会有非常多的条件语句，有没有什么更好的办法呢？我们在分析看看。商品有三种，性别相应着男、女，那么我们为什么不从还有一个角度来思考问题，不再建立生产shoes、shirt和suit的工厂。而是建立生产男人的衣服工厂ManCloseFactory和生产女人衣服的工厂WomanCLoseFactory。例如以下设计：
类图设计好了。如今仅仅须要两个工厂就能搞定了，那么编代码试试吧：
shirt接口：
public interface Shirt {
public String getInfo();
}suit接口：
public interface Suit {
public String getInfo();
}shoes接口：
public interface Shoes {
public String getInfo();
}ManShirt类：
public class ManShirt implements Shirt {
@Override
public String getInfo() {
// TODO Auto-generated method stub
String info = "男 衬衫";
return info;
}
}WomanShirt类：
public class WomanShirt implements Shirt {
@Override
public String getInfo() {
// TODO Auto-generated method stub
String info = "女 衬衫";
return info;
}
}ManSuit类：
public class ManSuit implements Suit {
@Override
public String getInfo() {
// TODO Auto-generated method stub
String info = "男 套装";
return info;
}
}WomanSuit类：
public class WomanSuit implements Suit {
@Override
public String getInfo() {
// TODO Auto-generated method stub
String info = "女 套装";
return info;
}
}ManShoes类：
public class ManShoes implements Shoes {
@Override
public String getInfo() {
// TODO Auto-generated method stub
String info = "男 鞋";
return info;
}
}WomanShoes类：
public class WomanShoes implements Shoes {
@Override
public String getInfo() {
// TODO Auto-generated method stub
String info = "女 鞋";
return info;
}
}工厂类的基类：
public abstract class CloseFactory {
public static final String MAN = "男";
public static final String WOMAN = "女";
public abstract Shoes getShoes();
public abstract Suit getSuit();
public abstract Shirt getShirt();
public static CloseFactory getCloseFactory(String Sex){
CloseFactory CF = null;
if(Sex.equals(MAN)){
CF = new ManCloseFactory();
}else if(Sex.equals(WOMAN)){
CF = new WomanCloseFactory();
}
return CF;
}
}男服生产工厂，ManCloseFactory：
public class ManCloseFactory extends CloseFactory {
@Override
public Shoes getShoes() {
// TODO Auto-generated method stub
return new ManShoes();
}
@Override
public Suit getSuit() {
// TODO Auto-generated method stub
return new ManSuit();
}
@Override
public Shirt getShirt() {
// TODO Auto-generated method stub
return new ManShirt();
}
}女服生产工厂，WomanCloseFactory：
public class WomanCloseFactory extends CloseFactory {
@Override
public Shoes getShoes() {
// TODO Auto-generated method stub
return new WomanShoes();
}
@Override
public Suit getSuit() {
// TODO Auto-generated method stub
return new WomanSuit();
}
@Override
public Shirt getShirt() {
// TODO Auto-generated method stub
return new WomanShirt();
}
}client：
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextArea;
public class clientGUI extends JFrame implements ActionListener{
private String SHOES = "鞋";
private String SHIRT = "衬衫";
private String SUIT = "套装";
private String MAN = "男";
private String WOMAN = "女";
private JLabel labelShowSex;
private JLabel labelShowType;
private JTextArea textShowInfo;
private JComboBox ChoiceSex;
private JComboBox ChoiceType;
private JButton BtnOK;
private JButton BtnExit;
private JPanel panelNorth;
private JPanel panelCenter;
private JPanel panelSouth;
public void initComponents(){
labelShowSex = new JLabel("请选择性别：");
labelShowType = new JLabel("请选择服饰：");
textShowInfo = new JTextArea();
textShowInfo = new JTextArea();
textShowInfo.setColumns(20);
textShowInfo.setRows(100);
textShowInfo.setBackground(Color.PINK);
ChoiceSex = new JComboBox();
ChoiceSex.addItem(MAN);
ChoiceSex.addItem(WOMAN);
ChoiceType = new JComboBox();
ChoiceType.addItem(SHOES);
ChoiceType.addItem(SHIRT);
ChoiceType.addItem(SUIT);
BtnOK = new JButton("OK");
BtnOK.addActionListener(this);
BtnExit = new JButton("EXIT");
BtnExit.addActionListener(this);
panelNorth = new JPanel();
panelCenter = new JPanel();
panelSouth = new JPanel();
}
public void panelAddComponenets(){
panelNorth.add(labelShowSex);
panelNorth.add(ChoiceSex);
panelNorth.add(labelShowType);
panelNorth.add(ChoiceType);
panelCenter.add(textShowInfo);
panelSouth.add(BtnOK);
panelSouth.add(BtnExit);
}
public void mainFrameAddPanel(){
this.add("North", panelNorth);
this.add("Center", panelCenter);
this.add("South", panelSouth);
}
public void mianFramSet(){
Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
this.setLocation((d.width - this.getSize().width)/2, (d.height - this.getSize().height)/2);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setSize(300, 200);
this.setVisible(true);
}
public clientGUI(){
initComponents();
panelAddComponenets();
mainFrameAddPanel();
mianFramSet();
}
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
if(e.getSource() == BtnOK){
String Sex = ChoiceSex.getSelectedItem().toString();
String Type = ChoiceType.getSelectedItem().toString();
CloseFactory cf = CloseFactory.getCloseFactory(Sex);//依据性别调用对应的工厂
if(Type.equals(SHIRT)){//依据类型生产对应的产品
Shirt s = cf.getShirt();
String info = s.getInfo();
textShowInfo.setText(info);
}else if(Type.equals(SHOES)){
Shoes s = cf.getShoes();
String info = s.getInfo();
textShowInfo.setText(info);
}else if(Type.equals(SUIT)){
Suit s = cf.getSuit();
String info = s.getInfo();
textShowInfo.setText(info);
}
}
if(e.getSource() == BtnExit){
System.exit(0);
}
}
}
測试：
public class mian {
public static void main(String[] args) {
// TODO Auto-generated method stub
clientGUI cGUI = new clientGUI();
}
}
这样设计是不是好多了。！
！
总结一下，抽象工厂模式应用在产品类别不唯一的情况，而工厂模式应用在产品类别单一的情况。再画一下抽象工厂模式的设计图：
上节中说到。工厂方法符合开闭原则，可是抽象工厂方法仅仅是部分的符合开闭原则，举个样例：
