java设计模式之：策略模式+简单工厂模式+模板方法模式项目案例实战

关于这三种设计模式是什么这里就不再赘述，本篇文章主要讲的是应用，不理解概念的可以先看一下我的其他关于讲解设计模式的文章，接下来直接进入主题。

书接上文讲的策略+简单工厂模式，本次我们又引入了模板方法，将一些公用的方法定义在抽象类的方法中，不同子类各自实现各自的逻辑。

我们这次还是根据不同的渠道类型进行通知客户(渠道类型有短信sms、邮件email、钉钉dingTalk）

首先就是要有策略接口，接口里面要有一个方法就是通知的方法

java 复制代码

public interface PushChannelStrategy｛
   SendResult send(MessagePushParam param，BaseMsg baseMsg）;
｝

然后是抽象类，抽象类中定义发送的通用流程，各自具体发送流程下沉到各自实现类

java 复制代码

@Component
public abstract class AbstractPushChannelStrategy implements PushChannelStrategy{
    @Override
    public SendResult send(MessagePushParam parma,BaseMsg baseMsg){
       // 获取目标地址，各自实现类来获取receiveAddress
       ReceiverResult receiverResult =getReceiverAddress（param）；
       // 拿到通知的地址，即手机号、邮箱、钉钉id
       String receiverAddress=receiverResult.getReceiverAddress();
       // 非空校验
       if(StringUtils.isBlank(receiverAddress)){
          return new SendResult(MessageStatusEnum.SEND_ADDRESS_NOT_EXIST,param.getReceiverId(),receiverAddress);
       }
       // 开始发送(短信、邮件、钉钉)，各自实现发送逻辑
       return send(param,receiverAddress,baseMsg);
   }

   //获取目标地址
   public abstract ReceiverResult getReceiverAddress(MessagePushParam param);
   
   // 具体发送逻辑
   public abstract SendResult send(MessagePushParam param,String targetId,BaseMsg BaseMsg);

然后三个子类短信、邮件、钉钉

java 复制代码

@Slf4j
@Component
public class SmsPushChannelStrategy extends AbstractPushChannelStrategy｛
   @Autowired
   private NoticeClient noticeClient；
   @Autowired
   private CustomerGateway customerGateway；
   
   @Override
   public SendResult send（MessagePushParam param，String targetId，BaseMsg baseMsg）｛
       //1、send sms
       if(baseMsg instanceof Sms){
          Sms smsMsg=(Sms)baseMsg;
          NoticeResult noticeResult=noticeClient.sendSms（xxxx）；
          SendResult sendResult=new SendResult();
          sendResult.setMessageStatus（MessageStatusEnum.SUCCESS）；
          return sendResult；
        }
      throw new MessagePushException("渠道不支持该类型消息");
   ｝
   
   // 短信通知获取需要通知的手机号
   @Override
   public ReceiverResult getReceiverAddress(MessagePushParam param){
     if(param==null){
       return ReceiverResult.builder().status(MessageStatusEnum.SMS_QUERY_PARAM_NULL).build();
     }
     return customerGateway.getSmsResultByCustId(param.getCustomerId());
 }
}

邮件：

java 复制代码

@Slf4j
@Component
public class EmailPushChannelStrategy extends AbstractPushChannelStrategy｛
   @Autowired
   private NoticeClient noticeClient；
   @Autowired
   private CustomerGateway customerGateway；
   @Override
   public SendResult send（MessagePushParam param，String targetId，BaseMsg baseMsg）｛
       //1、send email
       if(baseMsg instanceof Email){
         
          Email emailMsg=(Email)baseMsg；
          NoticeResult noticeResult=noticeClient.sendEmail（xxxx）；
          sendResult.setMessageStatus（MessageStatusEnum.SUCCESS）；
          return sendResult；
       }
      throw new MessagePushException(xxx);
   ｝
   
   @Override
   public ReceiverResult getReceiverAddress(MessagePushParam param){
     if(param==null){
        return ReceiverResult.builder().status(xxx).build();
      }
     return customerGateway.getEmailResultByCustId(param.getCustomerId());
｝
}

钉钉：

java 复制代码

@Slf4j
@Component
public class DingTalkPushChannelStrategy extends AbstractPushChannelStrategy｛
   @Autowired
   private DingTalkClient dingTalkClient；
   @Autowired
   private SalesGateway salesGateway;
   
   @Override
   public SendResult send（MessagePushParam param，BaseMsg baseMsg）｛
       //1、send ding talk
       SendResult sendResult=dingTalkClient.send(xxx)；
       sendResult.setReceiverId（param.getSalesId());
       // 其他结果参数组装
       return sendResult；
   ｝
   
   // 根据销售id获取钉钉id
   @Override
   public ReceiverResult getReceiverAddress(MessagePushParam param){
      DingTalkResult dingTalkResult=salesGateway.getDingTalkResultBySalesId(param.getSalesId());
      if(dingTalkResult==null){
         return ReceiverResult.builder().status(xxx).receiverAddress(null).build();
       }
      return ReceiverResult.builder().status(MessageStatusEnum.SUCCESS).receiverAddress(dingTalkResult.getDingTalkId()).build();
｝
}

然后通过策略工厂来获取具体的策略类：(由于只有三个策略类，所以通过注入的方式对channel进行判断)

java 复制代码

@Component
public class PushChannelStrategyFactory｛
    @Autowired 
    private DingTalkPushChannelStrategy dingTalkPushChannelStrategy；
    @Autowired
    private SmsPushChannelStrategy smsPushChannelStrategy；
    @Autowired
    private EmailPushChannelStrategy emailPushChannelStrategy；
    
    public PushChannelStrategy getStrategy(PushChannel pushChannel)｛
        switch(pushChannel)｛
           case DING_TALK：
              return dingTalkPushChannelStrategy；
           case SMS：
              return smsPushChannelStrategy；
           case EMAIL：
              return emailPushChannelStrategy；
           default：
              throw new RuntimeException(＂不支持的类型＂)；
           ｝
     ｝
｝

当然策略工厂针对策略实现类比较少的情况还可以这样写：

java 复制代码

@Component
public class PushChannelStrategyFactory2｛
    @Autowired
    private DingTalkPushChannelStrategy dingTalkPushChannelStrategy;
    @Autowired
    private SmsPushChannelStrategy smsPushChannelStrategy;
    @Autowired
    private EmailPushChannelStrategy emailPushChannelStrategy;
    
    private static final Map<PushChannel,PushChannelStrategy> pushChannelBuilderMap=new HashMap<>();
    
    @PostConstruct
    public void init(){
        pushChannelBuilderMap.put(PushChannel.SMS,smsPushChannelStrategy);
        pushChannelBuilderMap.put(PushChannel.Email,emailPushChannelStrategy);
        pushChannelBuilderMap.put(PushChannel.DING_TALK,dingTalkPushChannelStrategy);
      }

   Public PushChannelStrategy getStrategy(PushChannel PushChannel){
      if(PushChannel==null){
          return null;
       }
       return pushChannelBuilderMap.get(PushChannel);
    }
}

枚举类：

java 复制代码

@Getter
public enum PushChannel{
   SMS(＂sms＂，＂短信＂），
   EMAIL(＂email＂，＂邮件＂），
   DING_TALK(＂dingTalk＂，＂钉钉＂）；
   
   private final String value;
   
   PushChannel(String value,String desc){
      this.value=value;
    }

   public static PushChannel getPushChannel(String pushChannel){
      if(pushChannel==null){
         return null;
      }
      for(PushChannel channel:PushChannel.values()){
        if(pushChannel.equals(channel.getValue())){
           return channel;
       }
   }
    return null;
  }
}

在使用的时候通过策略工厂里面的方法获取具体的策略类：

java 复制代码

@Slf4j
@Service
 public class MessagePushService{
     @Autowired
     private PushChannelStrategyFactory pushChannelStrategyFactory;
     @Autowired
     private MessageRecordRepository messageRecordRepository;
     
     public ResultDTO<Boolean> pushSync(MessagePushCommand command){
        MessagePushParam messagePushParam =MessagePushAssembler.convert(command);
        //1,业务逻辑处理
        //2、根据渠道进行触达
        PushChannel pushChannel=messagePushParam.getChannel();
        if(pushChannel==null){
          throw new MessagePushException(xxx);
        }
        //3、获取具体的策略类
        PushChannelStrategy PushChannelStrategy=pushChannelStrategyFactory.getStrategy(pushChannel);
        SendResult sendResult=PushChannelStrategy.send(messagePushParam,xxx);
        //4,记录落库
        return ResultDTO.getSuccessResult（true）；
    ｝
 ｝

到此就结束了，是不是比较简单，该案例为实际项目中用到的实际案例，并且这三种设计模式也是比较简单和比较常用的设计模式，欢迎各位指出不足之处以及共同成长与学习。