JAVA2EVERYONE: Get child components from a container

****************************************************************
COMPLETE SOURCE CODE FOR : GetChildComponentOfaContainer.java
****************************************************************


import java.awt.Frame;//IMPORT FRAME CLASS INTO THIS PROGRAM
import java.awt.Label;//IMPORT LABEL CLASS INTO THIS PROGRAM
import java.awt.TextField;//IMPORT TEXTFIELD CLASS INTO THIS PROGRAM
import java.awt.Button;//IMPORT BUTTON CLASS INTO THIS PROGRAM
import java.awt.Panel;//IMPORT PANEL CLASS INTO THIS PROGRAM
import java.awt.Component;//IMPORT COMPONENT CLASS INTO THIS PROGRAM

import java.awt.event.WindowListener;//IMPORT WINDOWLISTENER CLASS INTO THIS PROGRAM
import java.awt.event.WindowAdapter;//IMPORT WINDOWADAPTER CLASS INTO THIS PROGRAM
import java.awt.event.WindowEvent;//IMPORT WINDOWEVENT CLASS INTO THIS PROGRAM
import java.awt.event.ActionListener;//IMPORT ACTIONLISTENER CLASS INTO THIS PROGRAM
import java.awt.event.ActionEvent;//IMPORT ACTIONEVENT CLASS INTO THIS PROGRAM

import java.awt.FlowLayout;//IMPORT FLOWLAYOUT CLASS INTO THIS PROGRAM
import java.awt.BorderLayout;//IMPORT BORDERLAYOUT CLASS INTO THIS PROGRAM

import java.awt.Color;//IMPORT COLOR CLASS INTO THIS PROGRAM

import javax.swing.JOptionPane;//IMPORT JOPTIONPANE CLASS INTO THIS PROGRAM

public class GetChildComponentOfaContainer implements ActionListener
{
 Frame a=new Frame("GET CHILD COMPONENT IN CONTAINER");
 Panel b=new Panel();
 Button d=new Button("ADD NEW COMPONENT INTO MONSTER (A LABEL)");
 Button c=new Button("CLICK HERE TO SEE NUMBERS OF COMPONENTS IN MONSTER");
 
 public GetChildComponentOfaContainer()
 {
  //SET LAYOUT FOR FRAME a
  a.setLayout(new BorderLayout());
  
  //LISTEN TO WINDOW CLOSING EVENT FOR a
  //WHEN SOMEONE CLICK CLOSE BUTTON, THIS APPLICATION WILL TERMINATE.
  WindowListener wl=new WindowAdapter()
  {
   public void windowClosing(WindowEvent evt)
   {
    System.exit(0);
   }
  };
  
  //PANEL b, TO PLACE COMPONENT
  b.setBackground(Color.YELLOW);
  b.add(new Label("COMPONENT 1 : A LABEL"));
  b.add(new TextField("COMPONENT 2 : A TEXTFIELD"));
  b.add(new Button("COMPONENT 3 : A BUTTON"));
  a.add(b,BorderLayout.CENTER);
  
  //ADD ACTIONLISTENER FOR BUTTON TO MAKE IT FUNCTION WHEN SOMEONE CLICK.
  d.addActionListener(this);
  c.addActionListener(this);
  
  //PLACE BOTH THE BUTTONS INTO A CONTAINER AND AFTER THAT PLACE THE CONTAINER INTO a
  Panel e=new Panel();
  e.add(c);
  e.add(d);
  a.add(e,BorderLayout.SOUTH);
  
  //LABEL AT THE TOP OF a
  Label f=new Label("YELLOW AREA IS A PANEL WITH NAME MONSTER");
  f.setAlignment(Label.CENTER);
  a.add(f,BorderLayout.NORTH);
  
  a.addWindowListener(wl);
  a.setSize(800,600);
  a.setVisible(true);
 }
 
 //ALL BUTTON ACTION IS HERE
 public void actionPerformed(ActionEvent evt)
 {
  //ACTION FOR BUTTON "ADD NEW COMPONENT INTO MONSTER (A LABEL)"
  if(evt.getSource()==d)
  {
   b.add(new Label("NEW"));
   //The validate method is used to cause a container to lay out its subcomponents again.
   //So you can see the latest label("NEW") that you add.
   b.validate();
   a.validate();
  }
  
  //ACTION FOR BUTTON "CLICK HERE TO SEE NUMBERS OF COMPONENTS IN MONSTER"
  if(evt.getSource()==c)
  {
   Component[]arrayToStoreAllComponent=b.getComponents();//STORE ALL COMPONENT IN b IN AN ARRAY
   int numbersOfComponent=arrayToStoreAllComponent.length;//GET ARRAY LENGTH BECAUSE IT SAME TO NUMBERS OF COMPONENT
   JOptionPane.showMessageDialog(null,"NUMBERS OF CURRENT COMPONENT IN MONSTER IS : "+numbersOfComponent);
  }
 }
 
 //MAIN METHOD
 public static void main(String[]args)
 {
  GetChildComponentOfaContainer myObject=new GetChildComponentOfaContainer();
 }
}

****************************************************************
JUST COMPILE AND EXECUTE IT
****************************************************************

Get child components from a container

RELAXING NATURE VIDEO