java.lang.Object
   java.text.Format
      java.text.NumberFormat
         java.text.DecimalFormat

All Implemented Interfaces:
    Cloneable, Serializable

This is an enhanced version of {@code DecimalFormat} that is based on the standard version in the RI. New or changed functionality is labeled NEW.

To obtain a NumberFormat for a specific locale (including the default locale), call one of {@code NumberFormat}'s factory methods such as {@code NumberFormat.getInstance}. Do not call the {@code DecimalFormat} constructors directly, unless you know what you are doing, since the NumberFormat factory methods may return subclasses other than {@code DecimalFormat}. If you need to customize the format object, do something like this:

NumberFormat f = NumberFormat.getInstance(loc);
if (f instanceof DecimalFormat) {
    ((DecimalFormat)f).setDecimalSeparatorAlwaysShown(true);
}

Example:

// Print out a number using the localized number, currency,
// and percent format for each locale
Locale[] locales = NumberFormat.getAvailableLocales();
double myNumber = -1234.56;
NumberFormat format;
for (int j = 0; j < 3; ++j) {
    System.out.println("FORMAT");
    for (int i = 0; i < locales.length; ++i) {
        if (locales[i].getCountry().length() == 0) {
            // Skip language-only locales
            continue;
        }
        System.out.print(locales[i].getDisplayName());
        switch (j) {
            case 0:
                format = NumberFormat.getInstance(locales[i]);
                break;
            case 1:
                format = NumberFormat.getCurrencyInstance(locales[i]);
                break;
            default:
                format = NumberFormat.getPercentInstance(locales[i]);
                break;
        }
        try {
            // Assume format is a DecimalFormat
            System.out.print(": "; + ((DecimalFormat)format).toPattern() + " -> "
                    + form.format(myNumber));
        } catch (Exception e) {
        }
        try {
            System.out.println(" -> " + format.parse(form.format(myNumber)));
        } catch (ParseException e) {
        }
    }
}

Patterns

A {@code DecimalFormat} consists of a pattern and a set of symbols. The pattern may be set directly using #applyPattern(String) , or indirectly using other API methods which manipulate aspects of the pattern, such as the minimum number of integer digits. The symbols are stored in a DecimalFormatSymbols object. When using the NumberFormat factory methods, the pattern and symbols are read from ICU's locale data.

Special Pattern Characters

Many characters in a pattern are taken literally; they are matched during parsing and are written out unchanged during formatting. On the other hand, special characters stand for other characters, strings, or classes of characters. For example, the '#' character is replaced by a localized digit. Often the replacement character is the same as the pattern character; in the U.S. locale, the ',' grouping character is replaced by ','. However, the replacement is still happening, and if the symbols are modified, the grouping character changes. Some special characters affect the behavior of the formatter by their presence; for example, if the percent character is seen, then the value is multiplied by 100 before being displayed.

To insert a special character in a pattern as a literal, that is, without any special meaning, the character must be quoted. There are some exceptions to this which are noted below.

The characters listed here are used in non-localized patterns. Localized patterns use the corresponding characters taken from this formatter's DecimalFormatSymbols object instead, and these characters lose their special status. Two exceptions are the currency sign and quote, which are not localized.

Symbol	Location	Localized?	Meaning
{@code 0}	Number	Yes	Digit.
{@code @}	Number	No	NEW  Significant digit.
{@code #}	Number	Yes	Digit, leading zeroes are not shown.
{@code .}	Number	Yes	Decimal separator or monetary decimal separator.
{@code -}	Number	Yes	Minus sign.
{@code ,}	Number	Yes	Grouping separator.
{@code E}	Number	Yes	Separates mantissa and exponent in scientific notation. Does not need to be quoted in prefix or suffix.
{@code +}	Exponent	Yes	NEW  Prefix positive exponents with localized plus sign. Does not need to be quoted in prefix or suffix.
{@code ;}	Subpattern boundary	Yes	Separates positive and negative subpatterns.
{@code %}	Prefix or suffix	Yes	Multiply by 100 and show as percentage.
{@code \u2030} ({@code \u2030})	Prefix or suffix	Yes	Multiply by 1000 and show as per mille.
{@code ¤} ({@code \u00A4})	Prefix or suffix	No	Currency sign, replaced by currency symbol. If doubled, replaced by international currency symbol. If present in a pattern, the monetary decimal separator is used instead of the decimal separator.
{@code '}	Prefix or suffix	No	Used to quote special characters in a prefix or suffix, for example, {@code "'#'#"} formats 123 to {@code "#123"}. To create a single quote itself, use two in a row: {@code "# o''clock"}.
{@code *}	Prefix or suffix boundary	Yes	NEW  Pad escape, precedes pad character.

A {@code DecimalFormat} pattern contains a postive and negative subpattern, for example, "#,##0.00;(#,##0.00)". Each subpattern has a prefix, a numeric part and a suffix. If there is no explicit negative subpattern, the negative subpattern is the localized minus sign prefixed to the positive subpattern. That is, "0.00" alone is equivalent to "0.00;-0.00". If there is an explicit negative subpattern, it serves only to specify the negative prefix and suffix; the number of digits, minimal digits, and other characteristics are ignored in the negative subpattern. This means that "#,##0.0#;(#)" produces precisely the same result as "#,##0.0#;(#,##0.0#)".

The prefixes, suffixes, and various symbols used for infinity, digits, thousands separators, decimal separators, etc. may be set to arbitrary values, and they will appear properly during formatting. However, care must be taken that the symbols and strings do not conflict, or parsing will be unreliable. For example, either the positive and negative prefixes or the suffixes must be distinct for #parse to be able to distinguish positive from negative values. Another example is that the decimal separator and thousands separator should be distinct characters, or parsing will be impossible.

The grouping separator is a character that separates clusters of integer digits to make large numbers more legible. It is commonly used for thousands, but in some locales it separates ten-thousands. The grouping size is the number of digits between the grouping separators, such as 3 for "100,000,000" or 4 for "1 0000 0000". There are actually two different grouping sizes: One used for the least significant integer digits, the primary grouping size, and one used for all others, the secondary grouping size. In most locales these are the same, but sometimes they are different. For example, if the primary grouping interval is 3, and the secondary is 2, then this corresponds to the pattern "#,##,##0", and the number 123456789 is formatted as "12,34,56,789". If a pattern contains multiple grouping separators, the interval between the last one and the end of the integer defines the primary grouping size, and the interval between the last two defines the secondary grouping size. All others are ignored, so "#,##,###,####", "###,###,####" and "##,#,###,####" produce the same result.

Illegal patterns, such as "#.#.#" or "#.###,###", will cause {@code DecimalFormat} to throw an IllegalArgumentException with a message that describes the problem.

Pattern BNF

pattern    := subpattern (';' subpattern)?
subpattern := prefix? number exponent? suffix?
number     := (integer ('.' fraction)?) | sigDigits
prefix     := '\\u0000'..'\\uFFFD' - specialCharacters
suffix     := '\\u0000'..'\\uFFFD' - specialCharacters
integer    := '#'* '0'* '0'
fraction   := '0'* '#'*
sigDigits  := '#'* '@' '@'* '#'*
exponent   := 'E' '+'? '0'* '0'
padSpec    := '*' padChar
padChar    := '\\u0000'..'\\uFFFD' - quote

Notation:
  X*       0 or more instances of X
  X?       0 or 1 instances of X
  X|Y      either X or Y
  C..D     any character from C up to D, inclusive
  S-T      characters in S, except those in T

Not indicated in the BNF syntax above:

• The grouping separator ',' can occur inside the integer and sigDigits elements, between any two pattern characters of that element, as long as the integer or sigDigits element is not followed by the exponent element.
• NEW  Two grouping intervals are recognized: The one between the decimal point and the first grouping symbol and the one between the first and second grouping symbols. These intervals are identical in most locales, but in some locales they differ. For example, the pattern "#,##,###" formats the number 123456789 as "12,34,56,789".
• NEW  The pad specifier {@code padSpec} may appear before the prefix, after the prefix, before the suffix, after the suffix or not at all.

Parsing

{@code DecimalFormat} parses all Unicode characters that represent decimal digits, as defined by Character#digit(int, int) . In addition, {@code DecimalFormat} also recognizes as digits the ten consecutive characters starting with the localized zero digit defined in the DecimalFormatSymbols object. During formatting, the DecimalFormatSymbols -based digits are written out.

During parsing, grouping separators are ignored.

If #parse(String, ParsePosition) fails to parse a string, it returns {@code null} and leaves the parse position unchanged.

Formatting

Formatting is guided by several parameters, all of which can be specified either using a pattern or using the API. The following description applies to formats that do not use scientific notation or significant digits.

• If the number of actual integer digits exceeds the maximum integer digits, then only the least significant digits are shown. For example, 1997 is formatted as "97" if maximum integer digits is set to 2.
• If the number of actual integer digits is less than the minimum integer digits, then leading zeros are added. For example, 1997 is formatted as "01997" if minimum integer digits is set to 5.
• If the number of actual fraction digits exceeds the maximum fraction digits, then half-even rounding is performed to the maximum fraction digits. For example, 0.125 is formatted as "0.12" if the maximum fraction digits is 2.
• If the number of actual fraction digits is less than the minimum fraction digits, then trailing zeros are added. For example, 0.125 is formatted as "0.1250" if the mimimum fraction digits is set to 4.
• Trailing fractional zeros are not displayed if they occur j positions after the decimal, where j is less than the maximum fraction digits. For example, 0.10004 is formatted as "0.1" if the maximum fraction digits is four or less.

Special Values

{@code NaN} is represented as a single character, typically {@code \uFFFD}. This character is determined by the DecimalFormatSymbols object. This is the only value for which the prefixes and suffixes are not used.

Infinity is represented as a single character, typically {@code \u221E}, with the positive or negative prefixes and suffixes applied. The infinity character is determined by the DecimalFormatSymbols object.

Scientific Notation

Numbers in scientific notation are expressed as the product of a mantissa and a power of ten, for example, 1234 can be expressed as 1.234 x 10³. The mantissa is typically in the half-open interval [1.0, 10.0) or sometimes [0.0, 1.0), but it does not need to be. {@code DecimalFormat} supports arbitrary mantissas. {@code DecimalFormat} can be instructed to use scientific notation through the API or through the pattern. In a pattern, the exponent character immediately followed by one or more digit characters indicates scientific notation. Example: "0.###E0" formats the number 1234 as "1.234E3".

• The number of digit characters after the exponent character gives the minimum exponent digit count. There is no maximum. Negative exponents are formatted using the localized minus sign, not the prefix and suffix from the pattern. This allows patterns such as "0.###E0 m/s". To prefix positive exponents with a localized plus sign, specify '+' between the exponent and the digits: "0.###E+0" will produce formats "1E+1", "1E+0", "1E-1", etc. (In localized patterns, use the localized plus sign rather than '+'.)
• The minimum number of integer digits is achieved by adjusting the exponent. Example: 0.00123 formatted with "00.###E0" yields "12.3E-4". This only happens if there is no maximum number of integer digits. If there is a maximum, then the minimum number of integer digits is fixed at one.
• The maximum number of integer digits, if present, specifies the exponent grouping. The most common use of this is to generate engineering notation, in which the exponent is a multiple of three, e.g., "##0.###E0". The number 12345 is formatted using "##0.###E0" as "12.345E3".
• When using scientific notation, the formatter controls the digit counts using significant digits logic. The maximum number of significant digits limits the total number of integer and fraction digits that will be shown in the mantissa; it does not affect parsing. For example, 12345 formatted with "##0.##E0" is "12.3E3". See the section on significant digits for more details.
• The number of significant digits shown is determined as follows: If no significant digits are used in the pattern then the minimum number of significant digits shown is one, the maximum number of significant digits shown is the sum of the minimum integer and maximum fraction digits, and it is unaffected by the maximum integer digits. If this sum is zero, then all significant digits are shown. If significant digits are used in the pattern then the number of integer digits is fixed at one and there is no exponent grouping.
• Exponential patterns may not contain grouping separators.

{@code DecimalFormat} has two ways of controlling how many digits are shown: (a) significant digit counts or (b) integer and fraction digit counts. Integer and fraction digit counts are described above. When a formatter uses significant digits counts, the number of integer and fraction digits is not specified directly, and the formatter settings for these counts are ignored. Instead, the formatter uses as many integer and fraction digits as required to display the specified number of significant digits.

Examples:

Pattern	Minimum significant digits	Maximum significant digits	Number	Output of format()
{@code @@@}	3	3	12345	{@code 12300}
{@code @@@}	3	3	0.12345	{@code 0.123}
{@code @@##}	2	4	3.14159	{@code 3.142}
{@code @@##}	2	4	1.23004	{@code 1.23}

• Significant digit counts may be expressed using patterns that specify a minimum and maximum number of significant digits. These are indicated by the {@code '@'} and {@code '#'} characters. The minimum number of significant digits is the number of {@code '@'} characters. The maximum number of significant digits is the number of {@code '@'} characters plus the number of {@code '#'} characters following on the right. For example, the pattern {@code "@@@"} indicates exactly 3 significant digits. The pattern {@code "@##"} indicates from 1 to 3 significant digits. Trailing zero digits to the right of the decimal separator are suppressed after the minimum number of significant digits have been shown. For example, the pattern {@code "@##"} formats the number 0.1203 as {@code "0.12"}.
• If a pattern uses significant digits, it may not contain a decimal separator, nor the {@code '0'} pattern character. Patterns such as {@code "@00"} or {@code "@.###"} are disallowed.
• Any number of {@code '#'} characters may be prepended to the left of the leftmost {@code '@'} character. These have no effect on the minimum and maximum significant digit counts, but may be used to position grouping separators. For example, {@code "#,#@#"} indicates a minimum of one significant digit, a maximum of two significant digits, and a grouping size of three.
• In order to enable significant digits formatting, use a pattern containing the {@code '@'} pattern character.
• In order to disable significant digits formatting, use a pattern that does not contain the {@code '@'} pattern character.
• The number of significant digits has no effect on parsing.
• Significant digits may be used together with exponential notation. Such patterns are equivalent to a normal exponential pattern with a minimum and maximum integer digit count of one, a minimum fraction digit count of the number of '@' characters in the pattern - 1, and a maximum fraction digit count of the number of '@' and '#' characters in the pattern - 1. For example, the pattern {@code "@@###E0"} is equivalent to {@code "0.0###E0"}.
• If signficant digits are in use then the integer and fraction digit counts, as set via the API, are ignored.

NEW  Padding

{@code DecimalFormat} supports padding the result of {@code format} to a specific width. Padding may be specified either through the API or through the pattern syntax. In a pattern, the pad escape character followed by a single pad character causes padding to be parsed and formatted. The pad escape character is '*' in unlocalized patterns. For example, {@code "$*x#,##0.00"} formats 123 to {@code "$xx123.00"}, and 1234 to {@code "$1,234.00"}.

• When padding is in effect, the width of the positive subpattern, including prefix and suffix, determines the format width. For example, in the pattern {@code "* #0 o''clock"}, the format width is 10.
• The width is counted in 16-bit code units (Java {@code char}s).
• Some parameters which usually do not matter have meaning when padding is used, because the pattern width is significant with padding. In the pattern "* ##,##,#,##0.##", the format width is 14. The initial characters "##,##," do not affect the grouping size or maximum integer digits, but they do affect the format width.
• Padding may be inserted at one of four locations: before the prefix, after the prefix, before the suffix or after the suffix. If padding is specified in any other location, #applyPattern throws an IllegalArgumentException . If there is no prefix, before the prefix and after the prefix are equivalent, likewise for the suffix.
• When specified in a pattern, the 16-bit {@code char} immediately following the pad escape is the pad character. This may be any character, including a special pattern character. That is, the pad escape escapes the following character. If there is no character after the pad escape, then the pattern is illegal.

Synchronization

{@code DecimalFormat} objects are not synchronized. Multiple threads should not access one formatter concurrently.

Also see:

Format
NumberFormat

 public DecimalFormat() 
{
        Locale locale = Locale.getDefault();
        icuSymbols = new com.ibm.icu.text.DecimalFormatSymbols(locale);
        symbols = new DecimalFormatSymbols(locale);
        dform = new com.ibm.icu.text.DecimalFormat();
        super.setMaximumFractionDigits(dform.getMaximumFractionDigits());
        super.setMaximumIntegerDigits(dform.getMaximumIntegerDigits());
        super.setMinimumFractionDigits(dform.getMinimumFractionDigits());
        super.setMinimumIntegerDigits(dform.getMinimumIntegerDigits());
}

 public DecimalFormat(String pattern) 
{
        Locale locale = Locale.getDefault();
        icuSymbols = new com.ibm.icu.text.DecimalFormatSymbols(locale);
        symbols = new DecimalFormatSymbols(locale);
        dform = new com.ibm.icu.text.DecimalFormat(pattern, icuSymbols);
        super.setMaximumFractionDigits(dform.getMaximumFractionDigits());
        super.setMaximumIntegerDigits(dform.getMaximumIntegerDigits());
        super.setMinimumFractionDigits(dform.getMinimumFractionDigits());
        super.setMinimumIntegerDigits(dform.getMinimumIntegerDigits());
}

 public DecimalFormat(String pattern,
    DecimalFormatSymbols value) 
{
        symbols = (DecimalFormatSymbols) value.clone();
        Locale locale = symbols.getLocale();
        icuSymbols = new com.ibm.icu.text.DecimalFormatSymbols(locale);
        copySymbols(icuSymbols, symbols);
        dform = new com.ibm.icu.text.DecimalFormat(pattern, icuSymbols);
        super.setMaximumFractionDigits(dform.getMaximumFractionDigits());
        super.setMaximumIntegerDigits(dform.getMaximumIntegerDigits());
        super.setMinimumFractionDigits(dform.getMinimumFractionDigits());
        super.setMinimumIntegerDigits(dform.getMinimumIntegerDigits());
}

 DecimalFormat(String pattern,
    DecimalFormatSymbols value,
    DecimalFormat icuFormat) 
{
        symbols = value;
        icuSymbols = value.getIcuSymbols();
        dform = icuFormat;
        super.setMaximumFractionDigits(dform.getMaximumFractionDigits());
        super.setMaximumIntegerDigits(dform.getMaximumIntegerDigits());
        super.setMinimumFractionDigits(dform.getMinimumFractionDigits());
        super.setMinimumIntegerDigits(dform.getMinimumIntegerDigits());
}

 public  void applyLocalizedPattern(String pattern) 
{
        dform.applyLocalizedPattern(pattern);
}

 public  void applyPattern(String pattern) 
{
        dform.applyPattern(pattern);
}

 public Object clone() 
{
        DecimalFormat clone = (DecimalFormat) super.clone();
        clone.dform = (com.ibm.icu.text.DecimalFormat) dform.clone();
        clone.symbols = (DecimalFormatSymbols) symbols.clone();
        return clone;
}

 public boolean equals(Object object) 
{
        if (this == object) {
            return true;
        }
        if (!(object instanceof DecimalFormat)) {
            return false;
        }
        DecimalFormat format = (DecimalFormat) object;
        return (this.dform == null ? format.dform == null : this.dform
                .equals(format.dform));
}

 public StringBuffer format(double value,
    StringBuffer buffer,
    FieldPosition position) 
{
        return dform.format(value, buffer, position);
}

 public StringBuffer format(long value,
    StringBuffer buffer,
    FieldPosition position) 
{
        return dform.format(value, buffer, position);
}

 public final StringBuffer format(Object number,
    StringBuffer toAppendTo,
    FieldPosition pos) 
{
        if (!(number instanceof Number)) {
            throw new IllegalArgumentException();
        }
        if (toAppendTo == null || pos == null) {
            throw new NullPointerException();
        }
        if (number instanceof BigInteger || number instanceof BigDecimal) {
            return dform.format(number, toAppendTo, pos);
        }
        return super.format(number, toAppendTo, pos);
}

 public AttributedCharacterIterator formatToCharacterIterator(Object object) 
{
        if (object == null) {
            throw new NullPointerException();
        }
        return dform.formatToCharacterIterator(object);
}

 public Currency getCurrency() 
{
        final com.ibm.icu.util.Currency cur = dform.getCurrency();
        final String code = (cur == null) ? "XXX" : cur.getCurrencyCode(); //$NON-NLS-1$
        return Currency.getInstance(code);
}

 public DecimalFormatSymbols getDecimalFormatSymbols() 
{
        return (DecimalFormatSymbols) symbols.clone();
}

 public int getGroupingSize() 
{
        return dform.getGroupingSize();
}

 public int getMultiplier() 
{
        return dform.getMultiplier();
}

 public String getNegativePrefix() 
{
        return dform.getNegativePrefix();
}

 public String getNegativeSuffix() 
{
        return dform.getNegativeSuffix();
}

 public String getPositivePrefix() 
{
        return dform.getPositivePrefix();
}

 public String getPositiveSuffix() 
{
        return dform.getPositiveSuffix();
}

 public RoundingMode getRoundingMode() 
{
		// return the RoundingMode of this DecimalFormat
		return roundingMode;
}

 public int hashCode() 
{
        return dform.hashCode();
}

 public boolean isDecimalSeparatorAlwaysShown() 
{
        return dform.isDecimalSeparatorAlwaysShown();
}

 public boolean isGroupingUsed() 
{
        return dform.isGroupingUsed();
}

 public boolean isParseBigDecimal() 
{
        return this.parseBigDecimal;
}

 public boolean isParseIntegerOnly() 
{
        return dform.isParseIntegerOnly();
}

 public Number parse(String string,
    ParsePosition position) 
{
        Number number = dform.parse(string, position);
        if (null == number) {
            return null;
        }
        if (this.isParseBigDecimal()) {
            if (number instanceof Long) {
                return new BigDecimal(number.longValue());
            }
            if ((number instanceof Double) && !((Double) number).isInfinite()
                    && !((Double) number).isNaN()) {
                return new BigDecimal(number.doubleValue());
            }
            if (number instanceof BigInteger) {
                return new BigDecimal(number.doubleValue());
            }
            if (number instanceof com.ibm.icu.math.BigDecimal) {
                return new BigDecimal(number.toString());
            }
            return number;
        }
        if ((number instanceof com.ibm.icu.math.BigDecimal)
                || (number instanceof BigInteger)) {
            return new Double(number.doubleValue());
        }
        if (this.isParseIntegerOnly() && number.equals(NEGATIVE_ZERO_DOUBLE)) {
            return new Long(0);
        }
        return number;
}

 public  void setCurrency(Currency currency) 
{
        dform.setCurrency(com.ibm.icu.util.Currency.getInstance(currency
                .getCurrencyCode()));
        symbols.setCurrency(currency);
}

 public  void setDecimalFormatSymbols(DecimalFormatSymbols value) 
{
        if (value != null) {
            symbols = (DecimalFormatSymbols) value.clone();
            icuSymbols = dform.getDecimalFormatSymbols();
            copySymbols(icuSymbols, symbols);
            dform.setDecimalFormatSymbols(icuSymbols);
        }
}

 public  void setDecimalSeparatorAlwaysShown(boolean value) 
{
        dform.setDecimalSeparatorAlwaysShown(value);
}

 public  void setGroupingSize(int value) 
{
        dform.setGroupingSize(value);
}

 public  void setGroupingUsed(boolean value) 
{
        dform.setGroupingUsed(value);
}

 public  void setMaximumFractionDigits(int value) 
{
        super.setMaximumFractionDigits(value);
        dform.setMaximumFractionDigits(value);
        // update the RoundingIncrement
		setRoundingIncrement(value);
}

 public  void setMaximumIntegerDigits(int value) 
{
        super.setMaximumIntegerDigits(value);
        dform.setMaximumIntegerDigits(value);
}

 public  void setMinimumFractionDigits(int value) 
{
        super.setMinimumFractionDigits(value);
        dform.setMinimumFractionDigits(value);
}

 public  void setMinimumIntegerDigits(int value) 
{
        super.setMinimumIntegerDigits(value);
        dform.setMinimumIntegerDigits(value);
}

 public  void setMultiplier(int value) 
{
        dform.setMultiplier(value);
}

 public  void setNegativePrefix(String value) 
{
        dform.setNegativePrefix(value);
}

 public  void setNegativeSuffix(String value) 
{
        dform.setNegativeSuffix(value);
}

 public  void setParseBigDecimal(boolean newValue) 
{
        this.parseBigDecimal = newValue;
}

 public  void setParseIntegerOnly(boolean value) 
{
        // In this implementation, com.ibm.icu.text.DecimalFormat is wrapped to
        // fulfill most of the format and parse feature. And this method is
        // delegated to the wrapped instance of com.ibm.icu.text.DecimalFormat.
        dform.setParseIntegerOnly(value);
}

 public  void setPositivePrefix(String value) 
{
        dform.setPositivePrefix(value);
}

 public  void setPositiveSuffix(String value) 
{
        dform.setPositiveSuffix(value);
}

 public  void setRoundingMode(RoundingMode roundingMode) 
{
		if (roundingMode == null) {
			// when the given RoundingMode is null, throw NullPointerException
			throw new NullPointerException();
		}
		// update the RoundingMode with the given RoundingMode
		this.roundingMode = roundingMode;
		// update the RoundingMode of com.ibm.icu.text.DecimalFormat
		switch(roundingMode){
		case CEILING:
			dform.setRoundingMode(com.ibm.icu.math.BigDecimal.ROUND_CEILING);
			break;
		case DOWN:
			dform.setRoundingMode(com.ibm.icu.math.BigDecimal.ROUND_DOWN);
			break;
		case UP:
			dform.setRoundingMode(com.ibm.icu.math.BigDecimal.ROUND_UP);
			break;
		case FLOOR:
			dform.setRoundingMode(com.ibm.icu.math.BigDecimal.ROUND_FLOOR);
			break;
		case HALF_DOWN:
			dform.setRoundingMode(com.ibm.icu.math.BigDecimal.ROUND_HALF_DOWN);
			break;
		case HALF_UP:
			dform.setRoundingMode(com.ibm.icu.math.BigDecimal.ROUND_HALF_UP);
			break;
		case UNNECESSARY:
			dform.setRoundingMode(com.ibm.icu.math.BigDecimal.ROUND_UNNECESSARY);
			break;
		case HALF_EVEN:
			dform.setRoundingMode(com.ibm.icu.math.BigDecimal.ROUND_HALF_EVEN);
			break;
		default:
			break;
		}
		// update the RoundingIncrement
		setRoundingIncrement(getMaximumFractionDigits());
}

 public String toLocalizedPattern() 
{
        return dform.toLocalizedPattern();
}

 public String toPattern() 
{
        return dform.toPattern();
}