枚举策略模式

枚举策略模式将枚举和策略模式相结合，能使代码更加简洁。以下是消息推送相关的案例

1、定义消息推送接口

package com.bitzh.strategy;

public interface MessagePushStrategy {

    void push(String content);

}

2、分别创建邮件推送、短信推送和企业微信推送三个类，实现消息推送接口

package com.bitzh.strategy.impl;

import com.bitzh.strategy.MessagePushStrategy;

public class EmailPushStrategy implements MessagePushStrategy {

    public void push(String content) {
        System.out.println(String.format("邮件消息推送：%s",content));
    }

}

package com.bitzh.strategy.impl;

import com.bitzh.strategy.MessagePushStrategy;

public class SMSPushStrategy implements MessagePushStrategy {

    public void push(String content) {
        System.out.println(String.format("短信消息推送：%s",content));
    }

}

package com.bitzh.strategy.impl;

import com.bitzh.strategy.MessagePushStrategy;

public class WeComPushStrategy implements MessagePushStrategy {

    public void push(String content) {
        System.out.println(String.format("企业微信消息推送：%s",content));
    }

}

3、创建枚举类，将相关策略作为枚举项

package com.bitzh.enums;

import com.bitzh.strategy.MessagePushStrategy;
import com.bitzh.strategy.impl.EmailPushStrategy;
import com.bitzh.strategy.impl.SMSPushStrategy;
import com.bitzh.strategy.impl.WeComPushStrategy;

public enum MessagePushEnum {

    EmailPushStrategy("email",new EmailPushStrategy()),
    SMSPushStrategy("sms",new SMSPushStrategy()),
    WeComPushStrategy("wecom",new WeComPushStrategy());

    private String pushType;
    private MessagePushStrategy pushStrategy;

    MessagePushEnum(String pushType,MessagePushStrategy pushStrategy){
        this.pushType = pushType;
        this.pushStrategy = pushStrategy;
    }

    public String getPushType() {
        return pushType;
    }

    public void setPushType(String pushType) {
        this.pushType = pushType;
    }

    public MessagePushStrategy getPushStrategy() {
        return pushStrategy;
    }

    public void setPushStrategy(MessagePushStrategy pushStrategy) {
        this.pushStrategy = pushStrategy;
    }

    public static MessagePushStrategy build(String pushType){
        if(pushType == null || "".equals(pushType))
            return null;
        for(MessagePushEnum pushEnum: MessagePushEnum.values()){
            if(pushType.equals(pushEnum.getPushType()))
                return pushEnum.getPushStrategy();
        }
        return null;
    }

}

4、进行测试

package com.bitzh;

import com.bitzh.enums.MessagePushEnum;

public class StrategyApplication {

    public static void main(String[] args) {
        MessagePushEnum.build("email").push("你好！");
        MessagePushEnum.build("sms").push("你好！");
        MessagePushEnum.build("wecom").push("你好！");
    }

}

测试结果：