Spring 实现策略模式

ゝ一世哀愁。 2022-06-01 06:58 201阅读 0赞

1.策略接口

package org.apel.bowen.controller;
    
    import java.math.BigDecimal;
    /**
     * 计算价格的接口
     * @author Bowin
     *
     */
    public interface Strategy {
    	/**
         * 计算价格
         * @return
         */
       public  BigDecimal calculatePrice();
    }

2.实现接口

package org.apel.bowen.controller;
    
    import java.math.BigDecimal;
    
    import org.springframework.stereotype.Service;
    /**
     * 普通用户
     * @author Bowin
     *
     */
    @Service("generalMember")
    public class GeneralMember implements Strategy{
    
    	@Override
    	public BigDecimal calculatePrice() {
    		return new BigDecimal("100");
    	}
    
    }

package org.apel.bowen.controller;
    
    import java.math.BigDecimal;
    
    import org.springframework.stereotype.Service;
    /**
     * vip用户
     * @author Bowin
     *
     */
    @Service("vipMember")
    public class VipMember  implements Strategy{
    
    	@Override
    	public BigDecimal calculatePrice() {
    		return new BigDecimal("80");
    	}
    
    }

package org.apel.bowen.controller;
    
    import java.math.BigDecimal;
    
    import org.springframework.stereotype.Service;
    /**
     * 超级会员
     * @author Bowin
     *
     */
    @Service("superMember")
    public class SuperMember implements Strategy{
    
    	@Override
    	public BigDecimal calculatePrice() {
    		return new BigDecimal("1");
    	}
    
    }

3.策略控制器

package org.apel.bowen.controller;
    
    import java.math.BigDecimal;
    import java.util.Map;
    import java.util.concurrent.ConcurrentHashMap;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Component;
    import org.springframework.util.StringUtils;
    /**
     * 策略管理器
     * @author Bowin
     *
     */
    @Component
    public class StrategyContext {
    	/**
    	 *使用线程安全的ConcurrentHashMap存储所有实现Strategy接口的Bean
    	 *key:beanName
    	 *value：实现Strategy接口Bean
    	 */
    	private final Map<String, Strategy> strategyMap = new ConcurrentHashMap<>();
    	
    	 /**
         * 注入所有实现了Strategy接口的Bean
         * @param strategyMap
         */
        @Autowired
        public StrategyContext(Map<String, Strategy> strategyMap) {
            this.strategyMap.clear();
            strategyMap.forEach((k, v)-> this.strategyMap.put(k, v));
        }
     
        /**
         * 计算价格
         * @param memberLevel   会员等级
         * @return              价格
         */
        public BigDecimal calculatePrice(String memberLevel) {
        	if(!StringUtils.isEmpty(memberLevel)){
        		return strategyMap.get(memberLevel).calculatePrice();
        	}
    		return null;
        }
    }

4.客户端调用

package org.apel.bowen.controller;
    
    import java.math.BigDecimal;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    /**
     * 前端控制器
     * @author Bowin
     *
     */
    @Controller
    @RequestMapping
    public class HelloController {
    	
    
    	 @Autowired
    	  private StrategyContext strategyContext;
    	 
    	  @RequestMapping("calculatePrice")
    	  public @ResponseBody BigDecimal calculatePrice(String memberLevel) {
    	        return strategyContext.calculatePrice(memberLevel);
    	  }
    	 
    }

5.访问测试: http://localhost:9999/calculatePrice?memberLevel=vipMember 返回 80