Java设计模式编程中简单工厂与抽象工厂模式的使用实例

//业务功能 
public interface ICalculation { 
  double getResult(double numA, double numB); 
} 

public class CalcAdd implements ICalculation { 
 
  @Override 
  public double getResult(double numA, double numB) { 
    System.out.println("加法"); 
    return numA + numB; 
  } 
 
} 

public class CalcSubtract implements ICalculation { 
 
  @Override 
  public double getResult(double numA, double numB) { 
    System.out.println("减法"); 
    return numA - numB; 
  } 
 
} 

/* 
 * 简单工厂模式 关注：对象的创建 
 * 建立一个工厂类，对实现了同一接口的或者是存在继承关系的一些类进行实例的创建 
 */ 
public class Test4Simple { 
  public static void main(String[] args) { 
//   String operation = "/"; 
    String operation = "+"; 
//   String operation = "-"; 
//   String operation = "*"; 
    double numA = 182, numB = 33; 
    ICalculation createCalc = CalcSimpleFactory.createCalc(operation); 
    double result = createCalc.getResult(numA, numB); 
    System.out.println(result); 
  } 
} 

public class CalcMultipleFactory { 
   
  public static ICalculation produceAdd() { 
    return new CalcAdd(); 
  } 
   
  public static ICalculation produceSubtract() { 
    return new CalcSubtract(); 
  } 
   
  public static ICalculation produceMultiply() { 
    return new CalcMultiply(); 
  } 
   
  public static ICalculation produceDivide() { 
    return new CalcDivide(); 
  } 
} 

public class Test4Multiple { 
 
  public static void main(String[] args) { 
    double numA = 182, numB = 33; 
     
    ICalculation createCalc = CalcMultipleFactory.produceAdd(); 
    double result = createCalc.getResult(numA, numB); 
    System.out.println(result); 
     
    createCalc = CalcMultipleFactory.produceSubtract(); 
    result = createCalc.getResult(numA, numB); 
    System.out.println(result); 
     
    createCalc = CalcMultipleFactory.produceMultiply(); 
    result = createCalc.getResult(numA, numB); 
    System.out.println(result); 
     
    createCalc = CalcMultipleFactory.produceDivide(); 
    result = createCalc.getResult(numA, numB); 
    System.out.println(result); 
  } 
} 

//抽象产品1 
public interface IProduct1 { 
  public void show(); 
} 

//抽象产品2 
public interface IProduct2 { 
  public void show(); 
} 

//实体产品1 
public class Product1 implements IProduct1 {  
  public void show() {  
    System.out.println("创建了1型产品");  
  }  
}  

//实体产品2 
public class Product2 implements IProduct2 { 
  public void show() { 
    System.out.println("创建了2型产品"); 
  } 
} 

/* 
 * 1A 1B属于Product1 同一产品等级结构中 
 * 2A 2B属于Product2 
 */ 
public class GradeProduct1A extends Product1 { 
 
  @Override 
  public void show() { 
    super.show(); 
    System.out.println("这是产品1下的:产品A"); 
  } 
   
} 

public class GradeProduct1B extends Product1 { 
 
  @Override 
  public void show() { 
    super.show(); 
    System.out.println("这是产品1下的:产品B"); 
  } 
} 

public class GradeProduct2A extends Product2 { 
 
  @Override 
  public void show() { 
    super.show(); 
    System.out.println("这是产品2下的:产品A"); 
  } 
} 

public class GradeProduct2B extends Product2 { 
 
  @Override 
  public void show() { 
    super.show(); 
    System.out.println("这是产品2下的:产品B"); 
  } 
} 

//抽象工厂 创建不同的抽象产品 
public interface IFactory { 
  public IProduct1 createProduct1A();//1类产品 型号A 
  public IProduct1 createProduct1B();//1类产品 型号B 
  public IProduct2 createProduct2A();//2类产品 型号A 
  public IProduct2 createProduct2B();//2类产品 型号B 
} 

//实体工厂 创建实体产品，返回类型为抽象产品 
public class Factory implements IFactory { 
 
  public IProduct1 createProduct1A() { 
    return new GradeProduct1A(); 
  } 
 
  public IProduct1 createProduct1B() { 
    return new GradeProduct1B(); 
  } 
 
  public IProduct2 createProduct2A() { 
    return new GradeProduct2A(); 
  } 
 
  public IProduct2 createProduct2B() { 
    return new GradeProduct2B(); 
  } 
} 

/* 
 * 抽象工厂模式：用来创建一组相关或者相互依赖的对象 
 * 
 * 流程：抽象工厂，实体工厂   生产产品 
 *   抽象产品，实体产品    实现产品功能 
 * 缺点：当需要增加一个产品(由抽象和实体构成)，工厂都需要更改 
 */ 
public class Test4Abstract { 
  public static void main(String[] args) { 
    IFactory factory = new Factory(); 
    IProduct1 product1a = factory.createProduct1A(); 
    product1a.show(); 
    IProduct1 product1b = factory.createProduct1B(); 
    product1b.show(); 
     
    IProduct2 product2a = factory.createProduct2A(); 
    product2a.show(); 
    IProduct2 product2b = factory.createProduct2B(); 
    product2b.show(); 
  } 
}