Swing Components taking up large amount of memory

Question

I created a table out of JLabels. I made it so that when the Jpanel the labels are in are resized, the text will scale accordingly. I initially forgot to set the default close operation on the JFrame so I ended up having a ton of instances of them running in the background, until eclipse said the stack/ heap was full. I added that so now it closes correctly, however it got me wondering how much one instance of it takes up. When it launches to its default size, it only takes up about 24000K. If you move it around a lot it peeks at about 200000K and sits at 180000 K if you leave it alone. Why is my program taking up so much memory?

/**
 * Class to create the specified table
 * @author CGordo01
 *
 */
public class WordDocumentTable extends JPanel{
    Font f;
    // Holds all the label, is used for resizing
    ArrayList<JLabel> allLabels= new ArrayList<JLabel>();
    /**
     * Creates the table
     */
    public WordDocumentTable(){

        // Sets the layout to a gridBagLayout
        this.setLayout(new GridBagLayout());
        //Adds a component listener
        this.addComponentListener(new ComponentAdapter() {
            @Override
            /**
             * If the component is resized makes the text fit the dimensions
             */
            public void componentResized(ComponentEvent e) {
                // Boolean used to see if the text width fits the component.
                Boolean fits= false;

                // value used to divide the components height by.
                int divider = 16;

                // Makes the font size scale according to the width and height.
                while(fits == false){
                    f = new Font("SansSerif", Font.PLAIN, e.getComponent().getHeight()/divider);
                    for (int i = 0; i<allLabels.size();i++){
                        allLabels.get(i).setFont(f);
                        //System.out.println(divider);
                        if(allLabels.get(i).getGraphics().getFontMetrics().stringWidth(allLabels.get(i).getText())>allLabels.get(i).getWidth()){
                            fits = false;
                            divider++;
                            break;
                        }
                        else{
                            fits = true;
                        }

                    }
                }
            }
        });
        makeLeftCells();

        makeMidCells();

        makeLongCells();

        makeTopCells();

    }
    /**
     * Creates the cells that are in between widths of the other cells
     */
    private void makeMidCells() {
        GridBagConstraints midCells = new GridBagConstraints();
        midCells.fill= GridBagConstraints.BOTH;
        midCells.weightx=1;
        midCells.weighty=1;
        midCells.gridwidth=4;
        midCells.gridy=9;
        midCells.gridx=1;

        JLabel b = new JLabel();
        b.setText(".Batch Total    " + "    985124  " + "      Patches ");
        b.setName("Previous Batch Total");
        b.setBackground(Color.white);
        b.setBorder(new LineBorder(Color.black));
        b.setOpaque(true);
        b.setFont(f);
        this.add(b,midCells);

        midCells.gridx=5;
        JLabel b2 = new JLabel();
        b2.setText(".Shift Total    " + "    985124  " + "      Patches ");
        b2.setName("Previous Shift Total");
        b2.setBackground(Color.white);
        b2.setBorder(new LineBorder(Color.black));
        b2.setOpaque(true);
        b2.setFont(f);
        this.add(b2,midCells);

        midCells.gridy=12;
        midCells.gridx=1;

        JLabel c = new JLabel();
        c.setText(".Batch Total    " + "    985124  " + "      Patches ");
        c.setName("Batch Total");
        c.setBackground(Color.white);
        c.setBorder(new LineBorder(Color.black));
        c.setOpaque(true);
        c.setFont(f);
        this.add(c,midCells);

        midCells.gridx=5;
        JLabel c2 = new JLabel();
        c2.setText(".Shift Total    " + "    985124  " + "      Patches ");
        c2.setName("Shift Total");
        c2.setBackground(Color.white);
        c2.setBorder(new LineBorder(Color.black));
        c2.setOpaque(true);
        c2.setFont(f);
        this.add(c2,midCells);

        allLabels.add(b);
        allLabels.add(b2);
        allLabels.add(c);
        allLabels.add(c2);
    }

        /**
         * Creates the cells which span much of the grid
         */
        private void makeLongCells() {
            GridBagConstraints longCells = new GridBagConstraints();
        longCells.fill= GridBagConstraints.BOTH;
        longCells.weightx=1;
        longCells.weighty=1;
        longCells.gridwidth=8;
        longCells.gridx=1;
        longCells.gridy=7;

        JLabel b = new JLabel();
        b.setText("Finish the Batch");
        b.setName("Previous Shift Goal");
        b.setBackground(Color.white);
        b.setBorder(new LineBorder(Color.black));
        b.setOpaque(true);
        b.setFont(f);
        this.add(b,longCells);

        longCells.gridy=8;

        JLabel c = new JLabel();
        c.setText("<html><p> blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah</p></html>");
        c.setName("Previous Shift Notes");
        c.setBackground(Color.white);
        c.setBorder(new LineBorder(Color.black));
        c.setOpaque(true);
        c.setFont(f);
        this.add(c,longCells);

        longCells.gridy=10;

        JLabel d = new JLabel();
        d.setText("Shift Goal");
        d.setName("Shift Goal");
        d.setBackground(Color.white);
        d.setBorder(new LineBorder(Color.black));
        d.setOpaque(true);
        d.setFont(f);
        this.add(d,longCells);

        longCells.gridy=11;

        JLabel e = new JLabel();
        e.setText("Shift Notes");
        e.setName("Shift Goal");
        e.setBackground(Color.white);
        e.setBorder(new LineBorder(Color.black));
        e.setOpaque(true);
        e.setFont(f);
        this.add(e,longCells);

        longCells.gridy=13;

        JLabel f2 = new JLabel();
        f2.setText("");
        f2.setName("WO Schedule Note");
        f2.setBackground(Color.white);
        f2.setBorder(new LineBorder(Color.black));
        f2.setOpaque(true);
        f2.setFont(f);
        this.add(f2,longCells);

        longCells.gridy=14;

        JLabel g = new JLabel();
        g.setText("");
        g.setName("Supervisor");
        g.setBackground(Color.white);
        g.setBorder(new LineBorder(Color.black));
        g.setOpaque(true);
        g.setFont(f);
        this.add(g,longCells);

        allLabels.add(b);
        allLabels.add(c);
        allLabels.add(d);
        allLabels.add(e);
        allLabels.add(f2);
        allLabels.add(g);

    }
    /**
     * Creates a 8x7 grid of small cells 
     */
    private void makeTopCells() {
        GridBagConstraints topCells = new GridBagConstraints();
        topCells.fill= GridBagConstraints.BOTH;
        topCells.weighty=1;
        topCells.weightx=1;
        for (int i = 0; i < 8; i++)
        {
            topCells.gridx=i+1;
            for (int j = 0; j < 7; j++)
            {
                topCells.gridy=j;
                JLabel b = new JLabel();
                b.setText("" + i + j);
                b.setName("" + i + j);
                b.setOpaque(true);
                b.setFont(f);
                if(j==0){
                    b.setBackground(new Color(242,242,242));
                }
                else{
                    b.setBackground(Color.white);
                }
                b.setBorder(new LineBorder(Color.black));
                allLabels.add(b);
                this.add(b,topCells);
            }
        }

    }

    private void makeLeftCells() {
        GridBagConstraints leftCells = new GridBagConstraints();

        leftCells.fill = GridBagConstraints.BOTH;
        leftCells.gridx = 0;
        leftCells.gridy = 0;
        leftCells.weightx=2;
        leftCells.weighty=1;

        JLabel titleBlock = new JLabel();
        titleBlock.setOpaque(true);
        titleBlock.setText("Delta Hydrogel A");
        titleBlock.setForeground(Color.white);
        titleBlock.setBackground(new Color(79,129,189));
        titleBlock.setBorder(new LineBorder(Color.black));
        titleBlock.setFont(f);

        this.add(titleBlock, leftCells);

        leftCells.gridy = 1;
        leftCells.gridheight=3;

        JLabel tallBlock1 = new JLabel();
        tallBlock1.setOpaque(true);
        tallBlock1.setText(".Day Shift");
        tallBlock1.setForeground(Color.black);
        tallBlock1.setBackground(new Color(242,242,242));
        tallBlock1.setBorder(new LineBorder(Color.black));
        tallBlock1.setFont(f);
        this.add(tallBlock1, leftCells);



        JLabel tallBlock2 = new JLabel();
        tallBlock2.setOpaque(true);
        tallBlock2.setText(".Night Shift");
        tallBlock2.setForeground(Color.black);
        tallBlock2.setBackground(new Color(242,242,242));
        tallBlock2.setBorder(new LineBorder(Color.black));
        tallBlock2.setFont(f);
        leftCells.gridy = 4;

        this.add(tallBlock2, leftCells);

        JLabel shortBlock1 = new JLabel();
        shortBlock1.setOpaque(true);
        shortBlock1.setText(".Previous Shift Goal");
        shortBlock1.setForeground(Color.black);
        shortBlock1.setBackground(new Color(242,242,242));
        shortBlock1.setBorder(new LineBorder(Color.black));
        shortBlock1.setFont(f);
        leftCells.gridy = 7;
        leftCells.gridheight=1;

        this.add(shortBlock1, leftCells);

        JLabel shortBlockTall = new JLabel();
        shortBlockTall.setOpaque(true);
        shortBlockTall.setText(".Previous Shift Notes");
        shortBlockTall.setForeground(Color.black);
        shortBlockTall.setBackground(new Color(242,242,242));
        shortBlockTall.setBorder(new LineBorder(Color.black));
        shortBlockTall.setFont(f);
        leftCells.gridy = 8;
        leftCells.ipady=50;

        this.add(shortBlockTall, leftCells);

        JLabel shortBlock2 = new JLabel();
        shortBlock2.setOpaque(true);
        shortBlock2.setText(".Previous Shift Output");
        shortBlock2.setForeground(Color.black);
        shortBlock2.setBackground(new Color(242,242,242));
        shortBlock2.setBorder(new LineBorder(Color.black));
        shortBlock2.setFont(f);
        leftCells.gridy = 9;
        leftCells.ipady=0;


        this.add(shortBlock2, leftCells);

        JLabel shortBlock3 = new JLabel();
        shortBlock3.setOpaque(true);
        shortBlock3.setText(".Shift Goals");
        shortBlock3.setForeground(Color.black);
        shortBlock3.setBackground(new Color(184,204,228));
        shortBlock3.setBorder(new LineBorder(Color.black));
        shortBlock3.setFont(f);
        leftCells.gridy = 10;
        leftCells.ipady=0;


        this.add(shortBlock3, leftCells);


        JLabel shortBlock4 = new JLabel();
        shortBlock4.setOpaque(true);
        shortBlock4.setText(".Shift Notes");
        shortBlock4.setForeground(Color.black);
        shortBlock4.setBackground(new Color(184,204,228));
        shortBlock4.setBorder(new LineBorder(Color.black));
        shortBlock4.setFont(f);
        leftCells.gridy = 11;
        leftCells.ipady=0;


        this.add(shortBlock4, leftCells);

        JLabel shortBlock5 = new JLabel();
        shortBlock5.setOpaque(true);
        shortBlock5.setText(".Output");
        shortBlock5.setForeground(Color.black);
        shortBlock5.setBackground(new Color(184,204,228));
        shortBlock5.setBorder(new LineBorder(Color.black));
        shortBlock5.setFont(f);
        leftCells.gridy = 12;


        this.add(shortBlock5, leftCells);

        JLabel shortBlock6 = new JLabel();
        shortBlock6.setOpaque(true);
        shortBlock6.setText(".WO Schedule Note");
        shortBlock6.setForeground(Color.black);
        shortBlock6.setBackground(new Color(184,204,228));
        shortBlock6.setBorder(new LineBorder(Color.black));
        shortBlock6 .setFont(f);
        leftCells.gridy = 13;

        this.add(shortBlock6, leftCells);

        JLabel shortBlock7 = new JLabel();
        shortBlock7.setOpaque(true);
        shortBlock7.setText(".Supervisor");
        shortBlock7.setForeground(Color.black);
        shortBlock7.setBackground(new Color(184,204,228));
        shortBlock7.setBorder(new LineBorder(Color.black));
        shortBlock7.setFont(f);
        leftCells.gridy = 14;

        this.add(shortBlock7, leftCells);

        allLabels.add(titleBlock);
        allLabels.add(tallBlock1);
        allLabels.add(tallBlock2);
        allLabels.add(shortBlock1);
        allLabels.add(shortBlockTall);
        allLabels.add(shortBlock2);
        allLabels.add(shortBlock3);
        allLabels.add(shortBlock4);
        allLabels.add(shortBlock5);
        allLabels.add(shortBlock6);
        allLabels.add(shortBlock7);



    }
    public static void main (String[] args)
    {
        JFrame J = new JFrame();
        J.setSize(600,400);
        J.setVisible(true);


        WordDocumentTable wdc= new WordDocumentTable();

        J.setContentPane(wdc);
        J.setVisible(true);
        J.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

}

Answer 1

You'll want to profile to be sure, but it may help to focus on your implementation of componentResized(). As the enclosing container is resized, the method will be invoked repeatedly. In the handler, you're continually instantiating a new Font inside a while loop. At a minimum, consider using deriveFont(). Note especially that the size parameter is a float, while your present calculation appears to use a truncating integer division.