第五章 工厂模式

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一、简单工厂模式

1、传统方式实现披萨订购( 可以忽略)

披萨父类 Pizza

package tanchishell.SJMS.factory;//抽象类 Pizza 后续的所有 披萨都继承该类
public abstract class Pizza {protected String name;//由于不同的披萨有着不同的原材料所有 准备原材料的方法是抽象的需要子类自己去实现public abstract void prepare();//一下流程是各种披萨共有的，子类继承后自动实现public void bake() {System.out.println(name + " baking;");}public void cut() {System.out.println(name + " cutting;");}public void box() {System.out.println(name + " boxing;");}public void setName(String name) {this.name = name;}
}

子类胡椒披萨 PepperPizza

package tanchishell.SJMS.factory;public class PepperPizza extends Pizza{@Overridepublic void prepare() {System.out.println("准备胡椒披萨的原材料");}
}

子类印度披萨 GreekPizza

package tanchishell.SJMS.factory;public class GreekPizza extends Pizza{@Overridepublic void prepare() {System.out.println("准备希腊披萨的原材料");}
}

订购披萨 OrderPizza

package tanchishell.SJMS.factory;import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;public class OrderPizza {//构造器public OrderPizza() {Pizza pizza = null;String orderType; // 订购披萨的类型do {orderType = getType();if (orderType.equals("greek")) {pizza = new GreekPizza();pizza.setName(" 希腊披萨 ");} else if (orderType.equals("pepper")) {pizza = new PepperPizza();pizza.setName("胡椒披萨");} else {System.out.println("请检查您的输入");break;}//输出 pizza 制作过程pizza.prepare();pizza.bake();pizza.cut();pizza.box();} while (true);}//获取披萨的类型private String getType() {try {BufferedReader strin = new BufferedReader(new InputStreamReader(System.in));System.out.println("input pizza 类型:");String str = strin.readLine();return str;} catch (IOException e) {e.printStackTrace();return "";}}}

订购披萨的 客户端 PizzaStore

package tanchishell.SJMS.factory;//订购Pizza的客户端
public class PizzaStore {public static void main(String[] args) {new OrderPizza();}}

运行结果

传统的方式的优缺点，新增子类需要修改的地方牵扯太多

传统方式的究极耦合

新增一个子类，所有的OrderPizza类都需要修改，一旦过多，耦合度极高。

2、使用简单工厂模式 🔞🔞🔞

完整代码

披萨父类 Pizza

package tanchishell.SJMS.factory;//抽象类 Pizza 后续的所有 披萨都继承该类
public abstract class Pizza {protected String name;//由于不同的披萨有着不同的原材料所有 准备原材料的方法是抽象的需要子类自己去实现public abstract void prepare();//以下流程是各种披萨共有的，子类继承后自动实现public void bake() {System.out.println(name + " baking;");}public void cut() {System.out.println(name + " cutting;");}public void box() {System.out.println(name + " boxing;");}public void setName(String name) {this.name = name;}
}

披萨子类 GreekPizza / PepperPizza / ChinesePizza

印度披萨

package tanchishell.SJMS.factory;public class GreekPizza extends Pizza{@Overridepublic void prepare() {System.out.println("准备希腊披萨的原材料");}
}

胡椒披萨

package tanchishell.SJMS.factory;public class PepperPizza extends Pizza{@Overridepublic void prepare() {System.out.println("准备胡椒披萨的原材料");}
}

中国披萨

package tanchishell.SJMS.factory;public class ChinesePizza extends Pizza {@Overridepublic void prepare() {System.out.println("准备中国披萨的原材料");}
}

订购披萨 OrderPizza

package tanchishell.SJMS.factory;import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;public class OrderPizza{//定义一个简单工厂对象
//    SimpleFactory simpleFactory = new SimpleFactory(); //如果OrderPizza 和 工厂类同生共死就是组合关系SimpleFactory simpleFactory;Pizza pizza = null;//构造器public OrderPizza(SimpleFactory simpleFactory) {setFactory(simpleFactory);}public void setFactory(SimpleFactory simpleFactory) {String orderType = ""; //用户输入的，先定义一个空串提供下面使用this.simpleFactory = simpleFactory; //设置简单工厂对象do {orderType = getType();//可以在这里更换工厂方法pizza = this.simpleFactory.createPizza(orderType);//输出 pizzaif(pizza != null) { //订购成功pizza.prepare();pizza.bake();pizza.cut();pizza.box();} else {System.out.println(" 订购披萨失败 ");break;}}while(true);}//获取用户需要披萨的类型private String getType() {try {BufferedReader strin = new BufferedReader(new InputStreamReader(System.in));System.out.println("input pizza 类型:");String str = strin.readLine();return str;} catch (IOException e) {e.printStackTrace();return "";}}}

披萨简单工厂 SimpleFactory

package tanchishell.SJMS.factory;/*** 添加新品种的 披萨 只需要添加一个Pizza子类和在工厂类中做一个判断*/public class SimpleFactory {//更加 orderType 返回对应的 Pizza 对象public Pizza createPizza(String orderType) {Pizza pizza = null;System.out.println("使用简单工厂模式");if (orderType.equals("greek")) {pizza = new GreekPizza();pizza.setName(" 希腊披萨 ");} else if (orderType.equals("chinese")) {pizza = new ChinesePizza();pizza.setName(" 中国披萨 ");} else if (orderType.equals("pepper")) {pizza = new PepperPizza();pizza.setName("胡椒披萨");}else if (orderType.equals("usa")){  //新增美国披萨pizza = new USAPizza();pizza.setName("我是美国披萨");}return pizza;}//简单工厂模式 也叫 静态工厂模public static Pizza createPizza2(String orderType) {Pizza pizza = null;System.out.println("使用简单工厂模式 2");if (orderType.equals("greek")) {pizza = new GreekPizza();pizza.setName(" 希腊披萨 ");} else if (orderType.equals("chinese")) {pizza = new ChinesePizza();pizza.setName(" 中国披萨 ");} else if (orderType.equals("pepper")) {pizza = new PepperPizza();pizza.setName("胡椒披萨");}return pizza;}
}

客户端订购披萨 PizzaStore

package tanchishell.SJMS.factory;//订购Pizza的客户端
public  class PizzaStore {public static void main(String[] args) {
//        new OrderPizza();//获取订单，传入一个工厂new OrderPizza(new SimpleFactory());System.out.println("退出程序");}}

添加披萨子类 USAPizza 美国披萨

package tanchishell.SJMS.factory;public class USAPizza extends Pizza{@Overridepublic void prepare() {System.out.println("准备制作美国披萨");}
}

运行结果

二、工厂方法模式

完整代码

披萨父类 Pizza

package tanchishell.SJMS.methedfactory;//抽象类 Pizza 后续的所有 披萨都继承该类
public abstract class Pizza {protected String name;//由于不同的披萨有着不同的原材料所有 准备原材料的方法是抽象的需要子类自己去实现public abstract void prepare();//以下流程是各种披萨共有的，子类继承后自动实现public void bake() {System.out.println(name + " baking;");}public void cut() {System.out.println(name + " cutting;");}public void box() {System.out.println(name + " boxing;");}public void setName(String name) {this.name = name;}
}

北京奶酪披萨 BJCheesePizza

public class BJCheesePizza extends Pizza{@Overridepublic void prepare() {setName("北京奶酪披萨");System.out.println("准备北京制作奶酪披萨");}
}

北京胡椒披萨 BJPepperPizza

public class BJPepperPizza extends Pizza {@Overridepublic void prepare() {setName("北京胡椒披萨");System.out.println("准备北京胡椒披萨的原材料");}
}

伦敦奶酪披萨 LDCheesePizza

public class LDCheesePizza extends Pizza{@Overridepublic void prepare() {setName("伦敦奶酪披萨");System.out.println("准备伦敦制作奶酪披萨");}
}

伦敦胡椒披萨 LDPepperPizza

public class LDPepperPizza extends Pizza {@Overridepublic void prepare() {setName("伦敦胡椒披萨");System.out.println("准备伦敦胡椒披萨的原材料");}
}

抽象订购披萨 OrderPizza （充当工厂角色）

package tanchishell.SJMS.methedfactory;import tanchishell.SJMS.factory.SimpleFactory;import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;public abstract class OrderPizza {//定义一个抽象方法，createPizza , 让各个工厂子类自己实现abstract Pizza createPizza(String orderType);// 构造器public OrderPizza() {Pizza pizza = null;String orderType; // 订购披萨的类型do {orderType = getType();pizza = createPizza(orderType); //抽象方法，由工厂子类完成//输出 pizza 制作过程pizza.prepare();pizza.bake();pizza.cut();pizza.box();} while (true);}//获取用户需要披萨的类型private String getType() {try {BufferedReader strin = new BufferedReader(new InputStreamReader(System.in));System.out.println("input pizza 类型: ---- pepper(胡椒口味) -----cheese（奶酪口味）");String str = strin.readLine();return str;} catch (IOException e) {e.printStackTrace();return "";}}}

订购披萨子类 BJOrderPizza / LDOrderPizza

BJOrderPizza

package tanchishell.SJMS.methedfactory;public class BJOrderPizza extends OrderPizza{@OverridePizza createPizza(String orderType) {Pizza pizza = null;if(orderType.equals("cheese")) {pizza = new BJCheesePizza();} else if (orderType.equals("pepper")) {pizza = new BJPepperPizza();}/*** 需要添加北京口味的披萨只需要设计一个披萨子类 并在 这里加一个判断*/return pizza;}
}

LDOrderPizza

package tanchishell.SJMS.methedfactory;public class LDOrderPizza extends OrderPizza{@OverridePizza createPizza(String orderType) {Pizza pizza = null;if(orderType.equals("cheese")) {pizza = new LDCheesePizza();} else if (orderType.equals("pepper")) {pizza = new LDPepperPizza();}
// TODO Auto-generated method stubreturn pizza;}
}

客户端订购披萨

package tanchishell.SJMS.methedfactory;import java.util.Scanner;public class PizzaStore {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);System.out.println("请选择您的口味---目前支持 1，北京口味 ----2，伦敦口味");int i = scanner.nextInt();if(i == 1){new BJOrderPizza();}if(i == 2){new LDOrderPizza();}}
}

运行结果

添加披萨口味

新增子类实现

在对应的 Order 实现类进行判断

测试

三、抽象工厂模式

抽象工厂模式是对简单工厂和工厂方法的一个整合

代码示例

pizza 代码和 工厂方法模式一致，就不写了

抽象工厂 AbsFactory 接口

public interface AbsFactory {//让下面的工厂子类来 具体实现Pizza createPizza(String orderType);
}

北京披萨工厂 BJFactory 实现 AbsFactory 接口

package tanchishell.SJMS.absFactory;public class BJFactory implements AbsFactory{@Overridepublic Pizza createPizza(String orderType) {System.out.println("~使用的是抽象工厂模式~");Pizza pizza = null;if(orderType.equals("cheese")) {pizza = new BJCheesePizza();} else if (orderType.equals("pepper")){pizza = new BJPepperPizza();}/*** 添加披萨子类和判断就能完成披萨口味的添加*/return pizza;}
}

伦敦披萨工厂 LDFactory 实现 AbsFactory 接口

package tanchishell.SJMS.absFactory;public class LDFactory implements AbsFactory{@Overridepublic Pizza createPizza(String orderType) {System.out.println("~使用的是抽象工厂模式~");Pizza pizza = null;if (orderType.equals("cheese")) {pizza = new LDCheesePizza();} else if (orderType.equals("pepper")) {pizza = new LDPepperPizza();}return pizza;}
}

披萨订购 OrderPizza 聚合 AbsFactory 接口

package tanchishell.SJMS.absFactory;import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;public class OrderPizza {AbsFactory factory;// 构造器public OrderPizza(AbsFactory factory) {setFactory(factory);}private void setFactory(AbsFactory factory) {Pizza pizza = null;String orderType = ""; // 用户输入this.factory = factory;do {orderType = getType();
// factory 可能是北京的工厂子类，也可能是伦敦的工厂子类pizza = factory.createPizza(orderType);if (pizza != null) { // 订购 okpizza.prepare();pizza.bake();pizza.cut();pizza.box();} else {System.out.println("订购失败");break;}} while (true);}// 写一个方法，可以获取客户希望订购的披萨种类private String getType() {try {BufferedReader strin = new BufferedReader(new InputStreamReader(System.in));System.out.println("input pizza 类型: ---- pepper(胡椒口味) -----cheese（奶酪口味）");String str = strin.readLine();return str;} catch (IOException e) {e.printStackTrace();return "";}}
}

客户端订购披萨

package tanchishell.SJMS.absFactory;import java.util.Scanner;public class PizzaStore {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);System.out.println("请选择您的口味---目前支持 1，北京口味 ----2，伦敦口味");int i = scanner.nextInt();if(i == 1){new OrderPizza(new BJFactory());}if(i == 2){new OrderPizza(new LDFactory());}}
}

运行结果

JDKの工厂模式: Calendar日历类

        Calendar cal = Calendar.getInstance();
// 注意月份下标从0开始，所以取月份要+1System.out.println("年:" + cal.get(Calendar.YEAR));System.out.println("月:" + (cal.get(Calendar.MONTH) + 1));System.out.println("日:" + cal.get(Calendar.DAY_OF_MONTH));System.out.println("时:" + cal.get(Calendar.HOUR_OF_DAY));System.out.println("分:" + cal.get(Calendar.MINUTE));System.out.println("秒:" + cal.get(Calendar.SECOND));

进入Calendar cal = Calendar.getInstance();

工厂模式小结