方案设计 1通用 3策略模式

目录

• 1.1　　　　策略模式demo

 

---

1　　　　策略模式demo

回到顶部

1.1　　　　策略模式demo

搭建spring项目（策略类，策略子类，策略枚举，getBean工具类）

 

• 测试类：

package com.example.jiayou.ceshi.strategy;

import org.springframework.stereotype.Controller;
import org.springframework.util.ObjectUtils;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * ErrorHandler
 *
 * @author 魏豆豆
 * @date 2020/12/6
 */
@Controller
/**
 *@Controller 用于标记在一个类上，使用它标记的类就是一个SpringMVC Controller 对象。分发处理器将会扫描使用了该注解的类的方法，并检测该方法是否使用了@RequestMapping 注解
 */

@RequestMapping("/main")
public class StrategyHandler {

    @RequestMapping("/strategy")
    public String strategy(String param){
        System.out.println("aaa");

        //demo1 son
        Strategy strategy = StrategyEnum.getStrategyById(param);//varible
        if(!ObjectUtils.isEmpty(strategy)){
            return strategy.process();
        }

        return "aaa";

    }
}

 

• 策略枚举

package com.example.jiayou.ceshi.strategy;

import lombok.Getter;
import org.apache.commons.lang.StringUtils;

public enum StrategyEnum {
    AAA("AAA",SpringUtils.getBean(StrategyImplAAA.class),"aaa");


    @Getter
    private String id;

    @Getter
    private Strategy strategy;

    @Getter
    private String remark;


    private StrategyEnum (String id,Strategy strategy,String remark){
        this.id = id;
        this.strategy = strategy;
        this.remark = remark;
    }

    public static Strategy getStrategyById(String id){
        if(StringUtils.isBlank(id)){
            throw new NullPointerException("策略id");
        }
        for(StrategyEnum strategyEnum : StrategyEnum.values()){
            if(StringUtils.equals(id,strategyEnum.id)){
                return strategyEnum.strategy;
            }
        }
        return null;

    }

}

 

• 策略类

package com.example.jiayou.ceshi.strategy;

import org.springframework.stereotype.Service;

@Service
public abstract class Strategy {

    public String process(){
        System.out.println("parent");
        return "parent";
    }


}

 

• 策略子类：

package com.example.jiayou.ceshi.strategy;

import org.springframework.stereotype.Component;

@Component
public class StrategyImplAAA extends Strategy {

    public String process(){
        System.out.println("childAAA");
        return "AAA";
    }

}

 

 

• 新建getBean工具类

package com.example.jiayou.ceshi.strategy;

import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
 
@Component
public class SpringUtils implements ApplicationContextAware {
    private static ApplicationContext context;
 
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) {
        SpringUtils.context = applicationContext;
    }
 
    public static <T> T getBean(Class<T> clazz) {
        return context.getBean(clazz);
    }
 
    public static Object getBean(String name) {
        return context.getBean(name);
    }
}

 

访问：

http://127.0.0.1:8080/main/strategy?param=AAA