Get selected JCheckBox

Complete source code below will show you, how to get selected JCheckBox.

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COMPLETE SOURCE CODE FOR : GetSelectedJCheckBox.java
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import javax.swing.JFrame;
import javax.swing.JCheckBox;
import javax.swing.JButton;
import javax.swing.JOptionPane;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class GetSelectedJCheckBox implements ActionListener
{
//Create String that will be use to hold selected JCheckBox text
String selectedCheckBox="";

//Create check box using JCheckBox
JCheckBox checkBox1=new JCheckBox("Duck");
JCheckBox checkBox2=new JCheckBox("Chicken");
JCheckBox checkBox3=new JCheckBox("Cow");
JCheckBox checkBox4=new JCheckBox("Sheep");

//Create button using JButton with text ( Get selected JCheckBox )
JButton button=new JButton("Get selected JCheckBox");

//method actionPerformed that we override because we implement ActionListener
public void actionPerformed(ActionEvent event)
{
 //Action for button
 if(event.getSource()==button)
 {
  //Check first JCheckBox is selected or not
  if(checkBox1.isSelected())
  {
   selectedCheckBox=selectedCheckBox+checkBox1.getText()+"\n";
  }
 
  //Check second JCheckBox is selected or not
  if(checkBox2.isSelected())
  {
   selectedCheckBox=selectedCheckBox+checkBox2.getText()+"\n";
  }
 
  //Check third JCheckBox is selected or not
  if(checkBox3.isSelected())
  {
   selectedCheckBox=selectedCheckBox+checkBox3.getText()+"\n";
  }
 
  //Check fourth JCheckBox is selected or not
  if(checkBox4.isSelected())
  {
   selectedCheckBox=selectedCheckBox+checkBox4.getText()+"\n";
  }
 
  //Show message that tell you, what check box that you selected
  JOptionPane.showMessageDialog(null,"Selected check box is : \n"+selectedCheckBox);
 
  //Make selectedCheckBox string like initial with empty string
  selectedCheckBox=new String("");
 }
}

//Constructor
public GetSelectedJCheckBox()
{
 //Create a window using JFrame with title ( Get selected JCheckBox )
 JFrame frame=new JFrame("Get selected JCheckBox");

 //Create layout that will be use by JFrame
 GridLayout gl=new GridLayout(5,1);

 //Add ActionListener to button
 button.addActionListener(this);

 //Set JFrame layout
 frame.setLayout(gl);

 //Add all created check box into JFrame
 frame.add(checkBox1);
 frame.add(checkBox2);
 frame.add(checkBox3);
 frame.add(checkBox4);

 //Add created button into JFrame
 frame.add(button);

 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 frame.setSize(350,200);
 frame.setVisible(true);
}

//Main method
public static void main(String[]args)
{
 GetSelectedJCheckBox gsjcb=new GetSelectedJCheckBox();
}
}

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JUST COMPILE AND EXECUTE IT
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