Four ways to implement Java time monitoring

1. Event object:
Typically inherits from Java.util.EventObject objects, which are defined by the developer themselves.

2. Event Source:
Is the source of the triggering event, and different event sources trigger different event types.

3. Event Listener:
The event listener is responsible for listening for events emitted by the event source. An event listener typically implements Java.util.EventListener this identity interface.

The entire process is such that the event source can register the event listener object and can send an event object to the event listener object. After the event occurs, the event source sends the event object to all the event listeners that have been registered.
The listener object then responds to the event based on the corresponding method within the event object.

Here are four ways to implement

Java code:

 PackageTT;ImportJava.awt.Color;ImportJava.awt.Container;Importjava.awt.FlowLayout;Importjava.awt.event.ActionEvent;ImportJava.awt.event.ActionListener;ImportJavax.swing.JButton;ImportJavax.swing.JDialog;ImportJavax.swing.JFrame;ImportJavax.swing.RootPaneContainer;/*** Self class as Event listener:*/classEventListener1extendsJFrameImplementsActionListener {PrivateJButton Btblue, Btdialog;  PublicEventListener1 () {Settitle ("Java GUI Event Listener Processing"); SetBounds (100, 100, 500, 350); SetLayout (NewFlowLayout ()); Btblue=NewJButton ("Blue"); Btdialog=NewJButton ("Pop window"); //Add a button to an event listenerBtblue.addactionlistener ( This); Btdialog.addactionlistener ( This);        Add (Btblue);        Add (Btdialog); SetVisible (true);    Setdefaultcloseoperation (Jframe.exit_on_close); }    //*************************** Event Handling ***************************@Override Public voidactionperformed (ActionEvent e) {if(E.getsource () = =btblue) {Container C=Getcontentpane ();        C.setbackground (Color.Blue); } Else if(E.getsource () = =Btdialog) {JDialog Dialog=NewJDialog (); Dialog.setbounds (300, 200, 400, 300); Dialog.setvisible (true); }    }}/*** Java Event Listener Processing--internal class processing **/classEventListener2extendsJFrame {PrivateJButton Btblue, Btdialog; //Construction Method     PublicEventListener2 () {Settitle ("Java GUI Event Listener Processing"); SetBounds (100, 100, 500, 350); SetLayout (NewFlowLayout ()); Btblue=NewJButton ("Blue"); Btdialog=NewJButton ("Pop window"); //adding Event listener objects (object oriented thinking)Btblue.addactionlistener (NewColoreventlistener ()); Btdialog.addactionlistener (NewDialogeventlistener ());        Add (Btblue);        Add (Btdialog); SetVisible (true);    Setdefaultcloseoperation (Jframe.exit_on_close); }    //internal class Coloreventlistener, implement ActionListener interface    classColoreventlistenerImplementsActionListener {@Override Public voidactionperformed (ActionEvent e) {Container C=Getcontentpane ();        C.setbackground (Color.Blue); }    }    //internal class Dialogeventlistener, implement ActionListener interface    classDialogeventlistenerImplementsActionListener {@Override Public voidactionperformed (ActionEvent e) {JDialog dialog=NewJDialog (); Dialog.setbounds (300, 200, 400, 300); Dialog.setvisible (true); }    }}/*** Java Event Listener processing--Anonymous internal class processing **/classEventListener3extendsJFrame {PrivateJButton Btblue, Btdialog;  PublicEventListener3 () {Settitle ("Java GUI Event Listener Processing"); SetBounds (100, 100, 500, 350); SetLayout (NewFlowLayout ()); Btblue=NewJButton ("Blue"); Btdialog=NewJButton ("Pop window"); //Add an event listener (anonymous class here)Btblue.addactionlistener (NewActionListener () {//Event Handling@Override Public voidactionperformed (ActionEvent e) {Container C=Getcontentpane ();            C.setbackground (Color.Blue);        }        }); //and Add event listenersBtdialog.addactionlistener (NewActionListener () {@Override Public voidactionperformed (ActionEvent e) {JDialog dialog=NewJDialog (); Dialog.setbounds (300, 200, 400, 300); Dialog.setvisible (true);        }        });        Add (Btblue);        Add (Btdialog); SetVisible (true);    Setdefaultcloseoperation (Jframe.exit_on_close); }}/*** Java Event Listener Processing--External class processing **/classEventListener4extendsJFrame {PrivateJButton Btblue, Btdialog;  PublicEventListener4 () {Settitle ("Java GUI Event Listener Processing"); SetBounds (100, 100, 500, 350); SetLayout (NewFlowLayout ()); Btblue=NewJButton ("Blue"); Btdialog=NewJButton ("Pop window"); //Add a button to an event listenerBtblue.addactionlistener (NewColoreventlistener ( This)); Btdialog.addactionlistener (NewDialogeventlistener ());        Add (Btblue);        Add (Btdialog); SetVisible (true);    Setdefaultcloseoperation (Jframe.exit_on_close); }}//External class Coloreventlistener, implement ActionListener interfaceclassColoreventlistenerImplementsActionListener {PrivateEventListener4 el; Coloreventlistener (EventListener4 el) { This. El =el; } @Override Public voidactionperformed (ActionEvent e) {Container C=El.getcontentpane ();    C.setbackground (Color.Blue); }}//External class Dialogeventlistener, implement ActionListener interfaceclassDialogeventlistenerImplementsActionListener {@Override Public voidactionperformed (ActionEvent e) {JDialog dialog=NewJDialog (); Dialog.setbounds (300, 200, 400, 300); Dialog.setvisible (true); }} Public classActionlistenertest { Public Static voidMain (String args[]) {NewEventListener4 (); }}

Four ways to implement Java time monitoring