Counts the number of matching brackets in Java

    /**
     * Counts the number of matching brackets: {}.
     *
     * @param message the string to examine
     * @return the number of matching brackets
     */

    private int countBrackets(final String message) {
        boolean openBracket = false;
        int count = 0;
        for (final Character ch : message.toCharArray()) {
            if (openBracket == true && ch.equals('}')) {
                openBracket = false;
                count++;
            }
            if (ch.equals('{')) {
                openBracket = true;
            }
        }
        return count;
    }

How to add icon for JComboBox items

public class ShowConboWithIcons extends JFrame {

    private static final long serialVersionUID = 1L;

    private static final ImageIcon INFO_ICON  = new ImageIcon("lock.jpg");
    private static final ImageIcon NONE_ICON  = new ImageIcon("lock.jpg");
    public final String NONE_STR = "None";
    private final String INFO_STR = "Info";

    private JComboBox comboBox;
    private JPanel    topPanel;

    private String[] str_arr = null;


    public ShowConboWithIcons(String[] str_arr) {
        this.str_arr = str_arr;    
    }


    public void createGUI(){

        setMinimumSize(new Dimension(100,100));
        setTitle("Demo");
        setLocation(200, 200);

        topPanel = new JPanel();
        getContentPane().add(topPanel, BorderLayout.CENTER);

        Map<Object, Icon> icons = new HashMap<Object, Icon>();

        icons.put(NONE_STR, NONE_ICON);
        icons.put(INFO_STR, INFO_ICON);

        comboBox = new JComboBox();
        comboBox.setRenderer(new IconListRenderer(icons));
        comboBox.addItem("None");

        for(String val : str_arr){
            comboBox.addItem(val);
        }

        topPanel.add(comboBox);

        super.addWindowListener(new WindowAdapter() {          
            public void windowClosing(WindowEvent e) {              
                dispose();          
            }          
        });
    }

    public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException {

        UIManager.setLookAndFeel( "com.sun.java.swing.plaf.windows.WindowsLookAndFeel" );  

        String[] str_arr = {"A", "B", "C", "D", "E"};

        ShowConboWithIcons T = new ShowConboWithIcons(str_arr);
        T.createGUI();
        T.setVisible(true);        
    }


    class IconListRenderer extends DefaultListCellRenderer{
        private static final long serialVersionUID = 1L;
        private Map<Object, Icon> icons = null;

        public IconListRenderer(Map<Object, Icon> icons){
            this.icons = icons;
        }

        @Override
        public Component getListCellRendererComponent(JList list, Object value, int index,boolean isSelected, boolean cellHasFocus)
        {
            JLabel label = (JLabel) super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);

            // Get icon to use for the list item value
            Icon icon = icons.get(value);

            if(!value.toString().equals(NONE_STR)){
                icon = icons.get(INFO_STR);
            }

            // Set icon to display for value
            label.setIcon(icon);
            return label;
        }
    }
}

RandomGaussian

public final class RandomGaussian {
 
  public static void main(String... aArgs){
    RandomGaussian gaussian = new RandomGaussian();
    double MEAN = 100.0f;
    double VARIANCE = 5.0f;
    for (int idx = 1; idx <= 10; ++idx){
      log("Generated : " + gaussian.getGaussian(MEAN, VARIANCE));
    }
  }
   
  private Random fRandom = new Random();
 
  private double getGaussian(double aMean, double aVariance){
      return aMean + fRandom.nextGaussian() * aVariance;
  }

  private static void log(Object aMsg){
    System.out.println(String.valueOf(aMsg));
  }
}

http://www.javapractices.com/topic/TopicAction.do?Id=62

How to convert a String of Binary values to a Float and vice-versa in Java?

here’s a solution to have the binary representation of the IEEE 754 floating-point “double format” bit layout for a float (it is basically the memory representation of a float) :

int intBits = Float.floatToIntBits(yourFloat);
String binary = Integer.toBinaryString(intBits);

For the reverse procedure :

int intBits = Integer.parseInt(myString, 2);
float myFloat = Float.intBitsToFloat(longBits);

Creating an enum in Java

private static enum PriceList {
    BAG("Computer Bag", 100.00),        
    COMPUTER("Computer", 2000.00);

    String product;
    double cost;

    PriceList (String aProduct, double aCost){
        product = aProduct;
        cost = aCost;
    }

    // getter methods
        public String getProduct() {
               return product;
        }
        public double getCost() {
               return cost;
        }

}