Observer mode (Observer pattern) Java built-in use method

The Java built-in Observer pattern is the implementation of several main functions of the observer pattern by inheriting the parent class:

Observerable (observable): is a parent class (class), Addobserver (), adding observers; Deleteobserver (), delete observer;

Notifyobservers (), notify the Observer, Setchanged (), confirm the change;

OBSERVER (Observer): Is an interface (interface), update (), updating the observer data;

Setchanged ()->notifyobservers (), you must first use setchanged (), and then use Notifyobservers (), that is, to confirm the submission, and then notify the Observer;

The Observer's update Interface update (observerable o, Object Arg), that is, you can use push or pull (pull);

If Notifyobservers (ARG), passing the argument, the push (push) method, if there is no argument, is the way to pull (pull), that is, by using the Get () method;

The notice (notify) Order of the Observer is the first in and out mode.

Observerable (observable) code:

/** 
 * @time May 22, 2014 * * *
package Observer.java;  
      
Import java.util.Observable;  
      
/** 
 * @author C.l.wang * */Public
class Weatherdata extends observable {  
    private float temperature;  
    private float humidity;  
    private float pressure;  
          
    Public Weatherdata () {} public  
          
    void Measurementschanged () {  
        setchanged ();  
        Notifyobservers ();  
    }  
          
    public void setmeasurements (float temperature, float humidity, float pressure) {  
        this.temperature = temperature;< c20/>this.humidity = humidity;  
        This.pressure = pressure;  
        Measurementschanged ();  
    }  
          
    public float gettemperature () {return  
        temperature;  
    }  
          
    public float gethumidity () {return  
        humidity;  
    }  
          
    public float getpressure () {return  
        pressure  
    }}  

OBSERVER (Observer) code:

/** * @time May 22, 2014 * * * Package Observer.java;  
Import java.util.Observable;  
      
Import Java.util.Observer;  
      
    /** * @author C.l.wang * */public class Currentconditionsdisplay implements Observer, Displayelement {  
    Observable observable;  
    private float temperature;  
          
    private float humidity;  
        Public Currentconditionsdisplay (observable observable) {this.observable = observable;  
    Observable.addobserver (this); }/* (non-javadoc) * @see observer.java.displayelement#display () * * * @Override Pub LIC void display () {//TODO auto-generated Method Stub System.out.println ("Current Conditions:" + te  
    Mperature + "F degrees and" + humidity + "% humidity");
    }/* (non-javadoc) * @see java.util.observer#update (java.util.Observable, java.lang.Object) * * @Override public void update (observable o, objeCT arg) {//TODO auto-generated method stub if (o instanceof weatherdata) {Weatherdata  
            Weatherdata = (weatherdata) o;  
            This.temperature = Weatherdata.gettemperature ();  
            This.humidity = Weatherdata.gethumidity ();  
        Display (); }  
    }  
      
}

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