设计模式之工厂模式

设计模式之工厂模式

工厂模式：

创建过程：

1. 创建Shape接口
   public interface Shape {
   void draw();
   }
2. 创建实现类：
   public class Circle implements Shape {
   @Override
   public void draw() {
   System.out.println(“this is a circle!”);
   }
   }

public class Square implements Shape {
@Override
public void draw() {
System.out.println(“this is a square!”);
}
}
3. 创建类的工厂：
public class ShapeFactory {
public static Shape getShape(String shape){
if(“circle”.equals(shape)){
return new Circle();
}else if(“square”.equals(shape)){
return new Square();
}else{
return null;
}
}
}
4. 利用测试类进行测试：
public class FMMain {
public static void main(String[] args) {
Shape circle = ShapeFactory.getShape(“circle”);
circle.draw();
}

}

抽象工厂模式：

创建过程：
5. 创建shape接口：
public interface Shape {
void draw();
}
2.创建shape实现类：
public class Circle implements Shape{

@Override
public void draw() {
	System.out.println("this is a Circle!");
}

}

public class Rectangle implements Shape{
@Override
public void draw() {
System.out.println(“this is a rectangle!”);
}
}

3. 创建Color接口：
   public interface Color {
   void fill();
   }

4. 创建Color实现类：
   public class Green implements Color {
   @Override
   public void fill() {
   System.out.println(“this is Green!”);
   }
   }
   public class Red implements Color{
   @Override
   public void fill() {
   System.out.println(“this is Red!”);
   }
   }

5. 为 Color 和 Shape 对象创建抽象类来获取工厂。
   public abstract class AbstractFactory {
   public abstract Color getColor(String color);
   public abstract Shape getShape(String shape);
   }

6. 创建扩展了 AbstractFactory 的工厂类
   public class ColorFactory extends AbstractFactory {
   @Override
   public Color getColor(String color) {
   if(“green”.equals(color)){
   return new Green();
   }else if(“red”.equals(color)){
   return new Red();
   }else{
   return null;
   }
   }

   @Override
   public Shape getShape(String shape) {
   return null;
   }
   }
   public class ShapeFactory extends AbstractFactory {
   @Override
   public Color getColor(String color) {
   return null;
   }

   @Override
   public Shape getShape(String shape) {
   if(“rectangle”.equals(shape)){
   return new Rectangle();
   }else if(“circle”.equals(shape)){
   return new Circle();
   }else{
   return null;
   }
   }
   }

7. 创建一个工厂生成器类
   public class FactoryProducer {
   public static AbstractFactory getFactory(String type){
   if(“color”.equals(type)){
   return new ColorFactory();
   }else if(“shape”.equals(type)){
   return new ShapeFactory();
   }else{
   return null;
   }
   }
   }

8. 使用 FactoryProducer 来获取 AbstractFactory，进行测试：
   public class AFMain {
   public static void main(String[] args) {
   AbstractFactory color = FactoryProducer.getFactory(“color”);
   Color green = color.getColor(“green”);
   green.fill();
   }
   }