6回答

• 

  慕用4550773

  2024-09-29 21:09:39

  观察者：
  

  com.lone.watcherlombok.lombok.java.util.function.BiConsumerWeatherObserver Observer {
      String BiConsumer<WeatherSubjectWeatherObserver> (Subject subject) {
          (!(subject WeatherSubject)) {
              IllegalArgumentException()}
          .accept((WeatherSubject) subject)}
  }

  
  

  测试：

  com.lone.watchercom.lone.watcher.WeatherSubject.Statelombok.extern.slf4j.Main {
      (String[] args) {
          Observer girlfriend = WeatherObserver((subjectobserver) -> {
              State state = subject.getSubjectState()(State.== state) {
                  .info(observer.getName()subject.getContent())}
          })Observer mother = WeatherObserver((subjectobserver) -> {
              State state = subject.getSubjectState()(State.== state || State.== state) {
                  .info(observer.getName()subject.getContent())}
          })WeatherSubject subject = WeatherSubject()subject.attach(girlfriend)
                  .attach(mother)subject.setSubjectState(State.)subject.setContent()}
  }

  
  

  可否这样写，用户自定义自己的行为，Subject的广播仍然存在，但在用户端过滤了。

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• 

  潇潇小饭

  2019-06-04 09:31:25

  实际订阅者 肯定是在数据库里面的    根据订阅者订阅的天气分类等 查出  订阅者进行发布

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• 

  Samrong

  2019-01-05 23:50:11

  定义三个observer列表~

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• 

  pardon110

  2018-09-08 14:47:12

  其实就下雨下雪晴天等等这些信息，是来源于数据，即来自己被观察者的依赖。通常是交给第三方类处理。

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• 

  qq__SuperAlpaca_0

  2018-03-09 10:30:39

  设计一种数据结构，方便用户订阅和系统反馈

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• 

  小and

  2018-01-11 19:38:57

  public class WheatherSubject {
  
      private List<WheatherObserver> mObservers = new ArrayList<>();
      private String wheather;
  
      public final static String SNOW = "下雪";
      public final static String RAIN = "下雨";
      public final static String SUNNY = "晴";
  
      public String getWheather() {
          return wheather;
      }
  
      public void setWheather(String wheather) {
          this.wheather = wheather;
          notifyObservers(wheather);
      }
  
      public void attach(WheatherObserver observer) {
          mObservers.add(observer);
      }
  
      public void detach(WheatherObserver observer) {
          mObservers.remove(observer);
      }
  
      public void notifyObservers(String wheather) {
          for (WheatherObserver observer : mObservers) {
              if (observer.getWheathers().size() < 1 || observer.getWheathers().contains(wheather)) {
                  observer.update(wheather);
              }
          }
      }
  }

  public class WheatherObserver {
  
      private ArrayList<String> mWheathers;
  
      public WheatherObserver(String... wheathers) {
          mWheathers = new ArrayList<>();
          mWheathers.addAll(Arrays.asList(wheathers));
      }
  
      public ArrayList<String> getWheathers() {
          return mWheathers;
      }
  
      public void setWheathers(ArrayList<String> wheathers) {
          if (mWheathers != null) {
              mWheathers.clear();
              mWheathers.addAll(wheathers);
          }
      }
  
      public void update(String wheather){
          System.out.print(wheather);
          Log.i("fy",wheather);
      }
  }

  public class WheaterClint {
  
      public static void main(String[] args){
  
          WheatherSubject subject = new WheatherSubject();
          WheatherObserver observerAll = new WheatherObserver();
          WheatherObserver observerSnow = new WheatherObserver(WheatherSubject.SNOW);
          WheatherObserver observerSnowAndRain = new WheatherObserver(WheatherSubject.SNOW,WheatherSubject.RAIN);
  
          subject.attach(observerAll);
          subject.attach(observerSnow);
          subject.attach(observerSnowAndRain);
  
          subject.setWheather(WheatherSubject.RAIN);
      }
  }

  
  

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