Answer to Question #201102 in Java | JSP | JSF for Hamza

Question

Design a GUI program to find the weighted average of four test scores. The four test scores and their respective weights are given in the following format:

testscore1 weight1

...

For example, the sample data is as follows:

75 0.20

95 0.35

85 0.15

65 0.30

The user is supposed to enter the data and press a Calculate button. The program must display the weighted average.

Answer 1

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;


public class WeightedAverageJFrame extends JFrame {
	private JTextField[] txtScores = new JTextField[4];
	private JTextField[] txtWeights = new JTextField[4];
	private JButton btnCalculate;
	/**
	 * Constructor
	 */
	public WeightedAverageJFrame() {
		setTitle("Weighted Average");
		setSize(300, 200);
		setLayout(new BorderLayout());
		setLocationRelativeTo(null);
		setDefaultCloseOperation(EXIT_ON_CLOSE);
		//add the main Panel
		JPanel pnlControls = new JPanel(new GridLayout(5, 3));
		add("Center", pnlControls);
		pnlControls.add(new JLabel());
		pnlControls.add(new JLabel("Score"));
		pnlControls.add(new JLabel("Weight"));
		//add Labels and TextFields
		for (int i = 0; i < txtScores.length; ++i) {
			pnlControls.add(new JLabel("Test score " + (i + 1)));
			txtScores[i] = new JTextField();
			txtWeights[i] = new JTextField();
			pnlControls.add(txtScores[i]);
			pnlControls.add(txtWeights[i]);
		}
		//add the button "Calculate" 
		btnCalculate = new JButton("Calculate");
		btnCalculate.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				double totalWeightedScore = 0.0;
				double totalWeight = 0.0;
				try {
					for (int i = 0; i < txtScores.length; ++i) {
						double score = Double.parseDouble(txtScores[i].getText());
						double weight = Double.parseDouble(txtWeights[i].getText());
						if (score < 0.0 || weight < 0.0) {
							throw new Exception();
						}
						//calculate total weighted score
						totalWeightedScore += score * weight;
						//calculate total weight
						totalWeight += weight;
					}
				} catch (Exception var11) {
					JOptionPane.showMessageDialog(null, "The input values are not must be positive numbers.");
				}
				if (totalWeight != 1.0) {
					JOptionPane.showMessageDialog(null, "The total weight is not 100%");
				} else {
					JOptionPane.showMessageDialog(null, "The weighted average is: " + totalWeightedScore);
				}
			}
		});
		this.add("South", btnCalculate);
	}
	/**
	 * Main method
	 * @param args
	 */
	public static void main(String[] args) {
		WeightedAverageJFrame weightedAverage = new WeightedAverageJFrame();
		weightedAverage.setVisible(true);
	}
}