Creating a Custom Event in Java

[Jagdish Gada]

Hello, I am learning java programming where we need to create a custom event. I am not able to achieve it. I have tried it, but I am getting error while achieving it. If you know the details about it, then please provide me some programming code about it. So, it will helpful to me.

[Reegan]

Hello, you can able to create a custom attributes by the use of the code below. So, just make use of it, and get your problem solved:

public class testing : System.EventArgs 
{   
private string msg;
public testing(string str) 
{
this.msg=str;
}
public string Message() 
{
return msg;
}
}

[MindSpace]

Hello, if you make use of the code below then you will able to get the information about the custom event in java:

public class CustomClass
 {
    private int first;
    public delegate void ChangingHandler (object obj, CustomClassArgs customClassArg);
    public event ChangingHandler handler;
        
    public CustomClass(int n) 
{
        this.first=n;
    }
    public void setOne(int p) 
{
        this.first=p;
        if (p<5) 
{
            CustomClassArgs customClassArg=new CustomClassArgs("Class is below, first value is : "+this.first);
            handler(this,customClassArg);
        }
    }

    public string strCheck() {
        return this.first.ToString();
    }
}

[Modifier]

Hey, I have got the code below for creating the custom event in java:

EventHandlerClass eveHandler = new EventHandlerClass();
Account account = new Account();
account.SubscribeAccountBalanceLowEvent(
new AccountBalanceEventHandler(eveHandler.HandleAccountLowEvent));
account.SubscribeAccountBalanceLowEvent(
new AccountBalanceEventHandler(eveHandler.HandleAccountLowEvent2));
account.Withdraw(2.3M, 1);
account.UnsubscribeAccountBalanceLowEvent(
new AccountBalanceEventHandler(eveHandler.HandleAccountLowEvent2));
account.Withdraw(2.3M, 2);
account.UnsubscribeAccountBalanceLowEvent(
new AccountBalanceEventHandler(eveHandler.HandleAccountLowEvent));
account.Withdraw(2.3M, 3);

[Praetor]

For creating custom event in java you must need to make use of the code below. I have check it, I think you will able to get details from it.

import java.util.EventListener;
import java.util.EventObject;
import javax.swing.event.EventListenerList;
class event extends EventObject 
{
  public event(Object obj) {
    super(obj);
  }
}
interface eventListener extends EventListener 
{
  public void myEventOccurred(event e);
}
class testing 
{
  protected EventListenerList list = new EventListenerList();
  public void addeventListener(eventListener elistener) 
{
    list.add(eventListener.class, elistener);
  }
  public void removeeventListener(eventListener elistener) 
{
    list.remove(eventListener.class, elistener);
  }
  void fireevent(event e) {
    Object[] elisteners = list.getListenerList();
    for (int i = 0; i < elisteners.length; i = i+2) 
{
      if (elisteners[i] == eventListener.class) 
{
        ((eventListener) elisteners[i+1]).myEventOccurred(e);
      }
    }
  }
}
public class Main {
  public static void main(String[] argv) throws Exception 
{
    testing c = new testing();
    c.addeventListener(new eventListener() 
{
      public void myEventOccurred(event e) 
{
        System.out.println("fired");
      }
    });

  }
}

[opaper]

Hello, If you make use of the code below then you will able to get the custom event in java. So, just make use of it, and get your problem solved.

public class custEvent extends EventObject
{ 
public custEvent(Object obj)
{ 
super(obj); 
} 
} 
public custEvent(Object obj) 
{
 super(obj); 
}
 }
public interface custEventListener extends EventListener 
{
 public void event(custEvent e);
 }
public class MyClass 
{ 
protected javax.swing.event.EventListenerList listenerList = new javax.swing.event.EventListenerList(); 
public void addcustEventListener(custEventListener listener) 
{ 
listenerList.add(custEventListener.class, listener); 
} 
 void firecustEvent(custEvent e) 
{ 
Object[] listeners = listenerList.getListenerList(); 
for (int i=0; i<listeners.length; i+=2) 
{
 if (listeners[i]==custEventListener.class) 
{
 ((custEventListener)listeners[i+1]).event(e); 
}
 } 
} 
}