How to use

NumberFormat

in

java.text

 float a = 8250325.12f;
float b = 4321456.31f;
float c = a + b;
System.out.println(NumberFormat.getCurrencyInstance().format(c));
// prints $12,571,782.00 (wrong)

BigDecimal a1 = new BigDecimal("8250325.12");
BigDecimal b1 = new BigDecimal("4321456.31");
BigDecimal c1 = a1.add(b1);
System.out.println(NumberFormat.getCurrencyInstance().format(c1));
// prints $12,571,781.43 (right)

/**
 * Format number.
 * @param n number to format, may not be null.
 * @return formatted value.
 */
private static synchronized String formatNumber(final Object n) {
  Locale currentLocale = Locale.getDefault();
  if (currentLocale != numberLocale || numberFormat == null) {
    numberLocale = currentLocale;
    numberFormat = NumberFormat.getInstance(currentLocale);
  }
  return numberFormat.format(n);
}

public static String offset2FileName(final long offset) {
  final NumberFormat nf = NumberFormat.getInstance();
  nf.setMinimumIntegerDigits(20);
  nf.setMaximumFractionDigits(0);
  nf.setGroupingUsed(false);
  return nf.format(offset);
}

  public String nextAnchor(Node node) {
    this.lastAnchorId++;
    NumberFormat format = NumberFormat.getNumberInstance();
    format.setMinimumIntegerDigits(3);
    format.setMaximumFractionDigits(0);// issue 172
    format.setGroupingUsed(false);
    String anchorId = format.format(this.lastAnchorId);
    return "id" + anchorId;
  }
}

/**
 * Returns the formatted string of the elapsed time.
 */
public String elapsedTimeAsString(long runTime) {
  return NumberFormat.getInstance().format((double) runTime / 1000);
}

@Test
public void parseLocalizedBigDecimalNumber3() {
  String bigDecimalAsString = "3.14159265358979323846";
  NumberFormat numberFormat = NumberFormat.getInstance(Locale.ENGLISH);
  Number bigDecimal = NumberUtils.parseNumber(bigDecimalAsString, BigDecimal.class, numberFormat);
  assertEquals(new BigDecimal(bigDecimalAsString), bigDecimal);
}

 BigDecimal numerator = new BigDecimal(5);
BigDecimal denominator = new BigDecimal(2);

//In current scenario
  Locale locale = new Locale("de", "DE");
  NumberFormat format = DecimalFormat.getInstance(locale);
  String number = format.format(numerator.divide(denominator));
  System.out.println("Parsed value is "+number); 

The output here will be 2,5

 double d = 1.2345;
DecimalFormat df = new DecimalFormat("#0.00");
System.out.println(df.format(d)); // will print 1.23
d = 3.400;
System.out.println(df.format(d)); // will print 3.40
d = 3.456;
System.out.println(df.format(d)); // will print 3.46

BigDecimal b = new BigDecimal(0.20001);
System.out.println(df.format(b)); // will print 0.20

  DecimalFormat df = (DecimalFormat) NumberFormat.getInstance(Locale.GERMAN);
  df.setParseBigDecimal(true);
  BigDecimal bd = (BigDecimal) df.parseObject(numberString);
  System.out.println(bd.toString());
} catch (ParseException e) {
  e.printStackTrace();
NumberFormat nf = NumberFormat.getInstance(Locale.GERMAN);
try {
  BigDecimal bd1 = new BigDecimal(nf.parse(numberString).toString());
  System.out.println(bd1.toString());
} catch (ParseException e) {
  e.printStackTrace();

 BigDecimal a = new BigDecimal("-54125412512.231515235346");
BigDecimal b = new BigDecimal("-1231254125412512.231515235346");

NumberFormat formatter = new DecimalFormat("#,###");
formatter.setRoundingMode(RoundingMode.HALF_UP);
formatter.setMinimumFractionDigits(4);
formatter.setMaximumFractionDigits(4);
System.out.println("Number : " + formatter.format(a));
System.out.println("Number : " + formatter.format(b));

 public static String readableFileSize(long size) {
  if(size <= 0) return "0";
  final String[] units = new String[] { "B", "kB", "MB", "GB", "TB" };
  int digitGroups = (int) (Math.log10(size)/Math.log10(1024));
  return new DecimalFormat("#,##0.#").format(size/Math.pow(1024, digitGroups)) + " " + units[digitGroups];
}

static DecimalFormat decConv = new DecimalFormat("00.00");
private JButton convertDegreesToDecimal;
private JButton convertDecimalToDegreesButton;
 JFrame window = new JFrame();
 window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 window.setVisible(true);
 window.setLayout(new GridLayout(2, 1));
 decimalPanel.setLayout(new FlowLayout());
 decimalInput = new JFormattedTextField(
   DecimalFormat.getInstance());
 decimalInput.setColumns(5);
 convertDecimalToDegreesButton = new JButton("convert");
 degreesPanel.setLayout(new FlowLayout());
 degreesInput = new JFormattedTextField(
   NumberFormat.getIntegerInstance());
 degreesInput.setColumns(2);
 minutesInput = new JFormattedTextField(
   NumberFormat.getIntegerInstance());
 minutesInput.setColumns(2);
 secondsInput = new JFormattedTextField(
   DecimalFormat.getInstance());
 secondsInput.setColumns(5);

String number = "12345678910111213141516000";
 BigDecimal bd = new BigDecimal(number);
 DecimalFormat formatter = new DecimalFormat("#,###,###,###.#####");
 System.out.println("You want it : " + formatter.format(bd));
 Number num = formatter.parse(number);
 System.out.println("You don't want it : " + formatter.format(num));

String s = "100000";
 Locale dutch = new Locale("nl", "NL");
 NumberFormat numberFormatDutch = NumberFormat.getCurrencyInstance(dutch);
 String c = numberFormatDutch.format(new BigDecimal(s.toString()));
 System.out.println("Currency Format: "+ c);
 try {
   Number  d = numberFormatDutch.parse(c);
   BigDecimal bd = new BigDecimal(d.toString());
   System.out.println(bd);
 } catch (ParseException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
 }

  decimal = Character.toString( format.getDecimalFormatSymbols().getDecimalSeparator() );
  setColumns( format.toPattern().length() );
  setHorizontalAlignment(JFormattedTextField.TRAILING);
  setText( format.format(0.0) );
public void setText(String text)
  Number number = format.parse(text, new ParsePosition(0));
        String text = format.format( format.parse( sb.toString() ) );
        super.replace(fb, 0, doc.getLength(), text, a);
      String text = format.format( format.parse( sb.toString() ) );
      super.replace(fb, 0, doc.getLength(), text, null);
  panel.add( abm );
  JFrame frame = new JFrame("ABMTextField");
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.add( panel );
  frame.setSize(200, 200);

/**
 * Returns a String summarizing recall that will print nicely.
 */
public String getRecallDescription(int numDigits) {
 NumberFormat nf = NumberFormat.getNumberInstance();
 nf.setMaximumFractionDigits(numDigits);
 return nf.format(getRecall()) + "  (" + tpCount + "/" + (tpCount + fnCount) + ")";
}

 public static boolean isNumber(String s){
  try{
    Locale l = Locale.getDefault();
    DecimalFormat df = new DecimalFormat("###.##;-##.##");
    Number n = df.parse(s);
    String sb = df.format(n);
    return sb.equals(s);
  }
  catch(Exception e){
    return false;
  }
}

 NumberFormat formatter = NumberFormat.getNumberInstance(Locale.GERMANY);
formatter.setMaximumFractionDigits(2);
formatter.setMinimumIntegerDigits(2);
formatter.setMinimumFractionDigits(2);
System.out.println((formatter.format(new BigDecimal(100)))); // prints "100,00"

 double myValue = 0.00000021d;

DecimalFormat df = new DecimalFormat("0", DecimalFormatSymbols.getInstance(Locale.ENGLISH));
df.setMaximumFractionDigits(340); //340 = DecimalFormat.DOUBLE_FRACTION_DIGITS

System.out.println(df.format(myValue)); //output: 0.00000021

 Locale l = Locale.getDefault();
DecimalFormat formatter = (DecimalFormat) NumberFormat.getInstance(l);

DecimalFormatSymbols symbols = formatter.getDecimalFormatSymbols();
symbols.setGroupingSeparator('.'); // setting the thousand separator
// symbols.setDecimalSeparator(','); optionally setting the decimal separator

formatter.setDecimalFormatSymbols(symbols);
formatter.setMinimumFractionDigits(2);
formatter.setMaximumFractionDigits(2);

String formattedString = formatter.format(yourDouble);