Drawing an image on a JPanel and adding it to a JFrame

Question

I am a high school student and I need to make a simple box and mustache. I cannot get the material that I draw on JPanel to appear on the JFrame. The picture simply does not appear. Can anyone help me?

public class BoxPlot extends JFrame { public final int MIN; public final double Q1; public final double MEDIAN; public final double Q3; public final int MAX; public BoxPlot(int[] data){ this.setLayout(new GridBagLayout()); this.MIN = Statistics.min(data); this.Q1 = Statistics.lowerQuartile(data); this.MEDIAN = Statistics.median(data); this.Q3 = Statistics.upperQuartile(data); this.MAX = Statistics.max(data); this.addBox(data); this.addSummary(); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); this.setSize(800, 600); this.setResizable(true); this.setVisible(true); } // Adds a panel with the boxplot private void addBox(int[] data) { Box box = new Box(data); GridBagConstraints c = new GridBagConstraints(); c.gridx = 0; c.gridy = 0; c.weighty = 1; this.add(box, c); } // Adds a panel with the five number summaries as JLabels // to the bottom of the JFrame private void addSummary() { JPanel summary = new JPanel(); summary.setLayout(new GridLayout()); JLabel l = new JLabel("Minimum: "+this.MIN, JLabel.CENTER); summary.add(l); l = new JLabel("First Quartile: "+this.Q1, JLabel.CENTER); summary.add(l); l = new JLabel("Median: "+this.MEDIAN, JLabel.CENTER); summary.add(l); l = new JLabel("Third Quartile: "+this.Q3, JLabel.CENTER); summary.add(l); l = new JLabel("Maximum: "+this.MAX, JLabel.CENTER); summary.add(l); GridBagConstraints c = new GridBagConstraints(); c.gridx = 0; c.gridy = 1; c.weightx = 1; c.ipady = 10; c.fill = GridBagConstraints.HORIZONTAL; c.anchor = GridBagConstraints.PAGE_END; this.add(summary, c); } 

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 public class Box extends JPanel{ private int min; private double q1; private double median; private double q3; private int max; public Box(int[] data) { this.min = Statistics.min(data); this.q1 = Statistics.lowerQuartile(data); this.median = Statistics.median(data); this.q3 = Statistics.upperQuartile(data); this.max = Statistics.max(data); } // paints the box onto the JPanel public void paintComponent(Graphics g){ int d1 =10 * (int) (this.q1-this.min); int d2 =10 * (int) (this.median-this.q1); int d3 =10 * (int) (this.q3-this.median); int d4 =10 * (int) (this.max-this.q3); g.drawLine(100, 150, 100+d1, 150); g.drawLine(100+d1+d2+d3, 150, 100+d1+d2+d3+d4, 150); g.setColor(Color.RED); g.fillRect(100+d1, 100, d2, 100); g.setColor(Color.BLUE); g.fillRect(100+d1+d2, 100, d3, 100); } 

Answer 1

You do not have a GridBagConstraints padding value for your Box component, so the component will not have any size.

You can use:

 c.fill = GridBagConstraints.BOTH;