基于spring ioc 实现的 策略模式

接口

//接口
public interface Shape {
   void draw();
}

实现

//实现1
@Service
public class Rectangle implements Shape {
   @Override
   public void draw() {
      System.out.println("Inside Rectangle::draw() method.");
   }
}

//实现2
@Serivce
public class Circle implements Shape {
   @Override
   public void draw() {
      System.out.println("Inside Circle::draw() method.");
   }
}

//实现3
@Service
public class Square implements Shape {
   @Override
   public void draw() {
      System.out.println("Inside Square::draw() method.");
   }
}

枚举类型

 
public enum SettingTypeEnum {
    
    RECTANGLE("1","Rectangle", "矩形"),
 
    SQUARE("2","Square", "正方形"),
    
    CIRCLE("3","Circle", "圆形"),
    ;
    public String code;
    //接口的实现类名
    public String implement;
    //备注
    public String desc;
 
    SettingTypeEnum(String code,String implement, String desc) {
        this.code = code;
        this.implement = implement;
        this.desc = desc;
    }
}

策略工厂

@Component
public class ShapeBeanFactory {
    
  @Autowired//关键在这个，原理：当一个接口有多个实现类的时候，key为实现类名，value为实现类对象
    private Map<String, Shape> shapeMap;
 
    @Autowired//这个注入了多个实现类对象
    private List<Shape> shapeList;
 
    public Shape getShape(String shapeType) {
        Shape bean1 = shapeMap.get(shapeType);
        System.out.println(bean1);
        return bean1;
    }
}

控制层或者业务层

@RestController
public class control {
    @Autowired
    private ShapeBeanFactory factory; // 使用注解注入
 
    @GetMapping("/drawMyShape")
    public String drawMyShape(){
        shapeBeanFactoryDraw();
        return "成功";
    }
 
    private void shapeBeanFactoryDraw() {
       
        //根据业务逻辑查库或者其他逻辑确定了一个类型
        String circle = SettingTypeEnum.CIRCLE.implement;
        //获取真正对象
        Shape shapeInterface1 = factory.getShape(circle);
        shapeInterface1.draw();
    }
}