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Préférences
Moteurs de recherche
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JavaTM 2 Platform Std. Ed. v1.6.0
java.text
|
Symbol | Location | Localized? | Meaning |
---|---|---|---|
0
| Number | Yes | Digit |
#
| Number | Yes | Digit, zero shows as absent |
.
| Number | Yes | Decimal separator or monetary decimal separator |
-
| Number | Yes | Minus sign |
,
| Number | Yes | Grouping separator |
E
| Number | Yes | Separates mantissa and exponent in scientific notation. Need not be quoted in prefix or suffix. |
;
| Subpattern boundary | Yes | Separates positive and negative subpatterns |
%
| Prefix or suffix | Yes | Multiply by 100 and show as percentage |
\u2030
| Prefix or suffix | Yes | Multiply by 1000 and show as per mille value |
¤ (\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. |
'
| Prefix or suffix | No | Used to quote special characters in a prefix or suffix,
for example, "'#'#" formats 123 to
"#123" . To create a single quote
itself, use two in a row: "# o''clock" .
|
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 10^3. The
mantissa is often in the range 1.0 <= x < 10.0, but it need not be.
DecimalFormat
can be instructed to format and parse scientific
notation only via a pattern; there is currently no factory method
that creates a scientific notation format. 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"
.
"0.###E0 m/s"
.
"##0.#####E0"
. Using this pattern, the number 12345
formats to "12.345E3"
, and 123456 formats to
"123.456E3"
.
"00.###E0"
yields
"12.3E-4"
.
"##0.##E0"
is "12.3E3"
. To show all digits, set
the significant digits count to zero. The number of significant digits
does not affect parsing.
DecimalFormat
provides rounding modes defined in
RoundingMode
for formatting. By default, it uses
RoundingMode.HALF_EVEN
.
DecimalFormat
uses the ten consecutive
characters starting with the localized zero digit defined in the
DecimalFormatSymbols
object as digits. For parsing, these
digits as well as all Unicode decimal digits, as defined by
Character.digit
, are recognized.
NaN
is formatted as a string, which typically has a single character
\uFFFD
. This string is determined by the
DecimalFormatSymbols
object. This is the only value for which
the prefixes and suffixes are not used.
Infinity is formatted as a string, which typically has a single character
\u221E
, with the positive or negative prefixes and suffixes
applied. The infinity string is determined by the
DecimalFormatSymbols
object.
Negative zero ("-0"
) parses to
BigDecimal(0)
if isParseBigDecimal()
is
true,
Long(0)
if isParseBigDecimal()
is false
and isParseIntegerOnly()
is true,
Double(-0.0)
if both isParseBigDecimal()
and isParseIntegerOnly()
are false.
Decimal formats are generally not synchronized. It is recommended to create separate format instances for each thread. If multiple threads access a format concurrently, it must be synchronized externally.
// Print out a number using the localized number, integer, currency, // and percent format for each locale Locale[] locales = NumberFormat.getAvailableLocales(); double myNumber = -1234.56; NumberFormat form; for (int j=0; j<4; ++j) { System.out.println("FORMAT"); for (int i = 0; i < locales.length; ++i) { if (locales[i].getCountry().length() == 0) { continue; // Skip language-only locales } System.out.print(locales[i].getDisplayName()); switch (j) { case 0: form = NumberFormat.getInstance(locales[i]); break; case 1: form = NumberFormat.getIntegerInstance(locales[i]); break; case 2: form = NumberFormat.getCurrencyInstance(locales[i]); break; default: form = NumberFormat.getPercentInstance(locales[i]); break; } if (form instanceof DecimalFormat) { System.out.print(": " + ((DecimalFormat) form).toPattern()); } System.out.print(" -> " + form.format(myNumber)); try { System.out.println(" -> " + form.parse(form.format(myNumber))); } catch (ParseException e) {} } }
Nested Class Summary |
---|
Nested classes/interfaces inherited from class java.text.NumberFormat |
---|
NumberFormat.Field |
Field Summary |
---|
Fields inherited from class java.text.NumberFormat |
---|
FRACTION_FIELD, INTEGER_FIELD |
Constructor Summary | |
---|---|
DecimalFormat()
Creates a DecimalFormat using the default pattern and symbols for the default locale. |
|
DecimalFormat(String pattern)
Creates a DecimalFormat using the given pattern and the symbols for the default locale. |
|
DecimalFormat(String pattern,
DecimalFormatSymbols symbols)
Creates a DecimalFormat using the given pattern and symbols. |
Method Summary | |
---|---|
void |
applyLocalizedPattern(String pattern)
Apply the given pattern to this Format object. |
void |
applyPattern(String pattern)
Apply the given pattern to this Format object. |
Object |
clone()
Standard override; no change in semantics. |
boolean |
equals(Object obj)
Overrides equals |
StringBuffer |
format(double number,
StringBuffer result,
FieldPosition fieldPosition)
Formats a double to produce a string. |
StringBuffer |
format(long number,
StringBuffer result,
FieldPosition fieldPosition)
Format a long to produce a string. |
StringBuffer |
format(Object number,
StringBuffer toAppendTo,
FieldPosition pos)
Formats a number and appends the resulting text to the given string buffer. |
AttributedCharacterIterator |
formatToCharacterIterator(Object obj)
Formats an Object producing an AttributedCharacterIterator . |
Currency |
getCurrency()
Gets the currency used by this decimal format when formatting currency values. |
DecimalFormatSymbols |
getDecimalFormatSymbols()
Returns a copy of the decimal format symbols, which is generally not changed by the programmer or user. |
int |
getGroupingSize()
Return the grouping size. |
int |
getMaximumFractionDigits()
Gets the maximum number of digits allowed in the fraction portion of a number. |
int |
getMaximumIntegerDigits()
Gets the maximum number of digits allowed in the integer portion of a number. |
int |
getMinimumFractionDigits()
Gets the minimum number of digits allowed in the fraction portion of a number. |
int |
getMinimumIntegerDigits()
Gets the minimum number of digits allowed in the integer portion of a number. |
int |
getMultiplier()
Gets the multiplier for use in percent, per mille, and similar formats. |
String |
getNegativePrefix()
Get the negative prefix. |
String |
getNegativeSuffix()
Get the negative suffix. |
String |
getPositivePrefix()
Get the positive prefix. |
String |
getPositiveSuffix()
Get the positive suffix. |
RoundingMode |
getRoundingMode()
Gets the RoundingMode used in this DecimalFormat. |
int |
hashCode()
Overrides hashCode |
boolean |
isDecimalSeparatorAlwaysShown()
Allows you to get the behavior of the decimal separator with integers. |
boolean |
isParseBigDecimal()
Returns whether the parse(java.lang.String, java.text.ParsePosition)
method returns BigDecimal . |
Number |
parse(String text,
ParsePosition pos)
Parses text from a string to produce a Number . |
void |
setCurrency(Currency currency)
Sets the currency used by this number format when formatting currency values. |
void |
setDecimalFormatSymbols(DecimalFormatSymbols newSymbols)
Sets the decimal format symbols, which is generally not changed by the programmer or user. |
void |
setDecimalSeparatorAlwaysShown(boolean newValue)
Allows you to set the behavior of the decimal separator with integers. |
void |
setGroupingSize(int newValue)
Set the grouping size. |
void |
setMaximumFractionDigits(int newValue)
Sets the maximum number of digits allowed in the fraction portion of a number. |
void |
setMaximumIntegerDigits(int newValue)
Sets the maximum number of digits allowed in the integer portion of a number. |
void |
setMinimumFractionDigits(int newValue)
Sets the minimum number of digits allowed in the fraction portion of a number. |
void |
setMinimumIntegerDigits(int newValue)
Sets the minimum number of digits allowed in the integer portion of a number. |
void |
setMultiplier(int newValue)
Sets the multiplier for use in percent, per mille, and similar formats. |
void |
setNegativePrefix(String newValue)
Set the negative prefix. |
void |
setNegativeSuffix(String newValue)
Set the negative suffix. |
void |
setParseBigDecimal(boolean newValue)
Sets whether the parse(java.lang.String, java.text.ParsePosition)
method returns BigDecimal . |
void |
setPositivePrefix(String newValue)
Set the positive prefix. |
void |
setPositiveSuffix(String newValue)
Set the positive suffix. |
void |
setRoundingMode(RoundingMode roundingMode)
Sets the RoundingMode used in this DecimalFormat. |
String |
toLocalizedPattern()
Synthesizes a localized pattern string that represents the current state of this Format object. |
String |
toPattern()
Synthesizes a pattern string that represents the current state of this Format object. |
Methods inherited from class java.text.NumberFormat |
---|
format, format, getAvailableLocales, getCurrencyInstance, getCurrencyInstance, getInstance, getInstance, getIntegerInstance, getIntegerInstance, getNumberInstance, getNumberInstance, getPercentInstance, getPercentInstance, isGroupingUsed, isParseIntegerOnly, parse, parseObject, setGroupingUsed, setParseIntegerOnly |
Methods inherited from class java.text.Format |
---|
format, parseObject |
Methods inherited from class java.lang.Object |
---|
finalize, getClass, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
---|
public DecimalFormat()
To obtain standard formats for a given locale, use the factory methods on NumberFormat such as getNumberInstance. These factories will return the most appropriate sub-class of NumberFormat for a given locale.
public DecimalFormat(String pattern)
To obtain standard formats for a given locale, use the factory methods on NumberFormat such as getNumberInstance. These factories will return the most appropriate sub-class of NumberFormat for a given locale.
pattern
- A non-localized pattern string.
NullPointerException
- if pattern
is null
IllegalArgumentException
- if the given pattern is invalid.NumberFormat.getInstance()
,
NumberFormat.getNumberInstance()
,
NumberFormat.getCurrencyInstance()
,
NumberFormat.getPercentInstance()
public DecimalFormat(String pattern, DecimalFormatSymbols symbols)
To obtain standard formats for a given locale, use the factory methods on NumberFormat such as getInstance or getCurrencyInstance. If you need only minor adjustments to a standard format, you can modify the format returned by a NumberFormat factory method.
pattern
- a non-localized pattern stringsymbols
- the set of symbols to be used
NullPointerException
- if any of the given arguments is null
IllegalArgumentException
- if the given pattern is invalidNumberFormat.getInstance()
,
NumberFormat.getNumberInstance()
,
NumberFormat.getCurrencyInstance()
,
NumberFormat.getPercentInstance()
,
DecimalFormatSymbols
Method Detail |
---|
public final StringBuffer format(Object number, StringBuffer toAppendTo, FieldPosition pos)
Number
.
This implementation uses the maximum precision permitted.
format
in class NumberFormat
number
- the number to formattoAppendTo
- the StringBuffer
to which the formatted
text is to be appendedpos
- On input: an alignment field, if desired.
On output: the offsets of the alignment field.
toAppendTo
IllegalArgumentException
- if number
is
null or not an instance of Number
.
NullPointerException
- if toAppendTo
or
pos
is null
ArithmeticException
- if rounding is needed with rounding
mode being set to RoundingMode.UNNECESSARYFieldPosition
public StringBuffer format(double number, StringBuffer result, FieldPosition fieldPosition)
format
in class NumberFormat
number
- The double to formatresult
- where the text is to be appendedfieldPosition
- On input: an alignment field, if desired.
On output: the offsets of the alignment field.
ArithmeticException
- if rounding is needed with rounding
mode being set to RoundingMode.UNNECESSARYFieldPosition
public StringBuffer format(long number, StringBuffer result, FieldPosition fieldPosition)
format
in class NumberFormat
number
- The long to formatresult
- where the text is to be appendedfieldPosition
- On input: an alignment field, if desired.
On output: the offsets of the alignment field.
ArithmeticException
- if rounding is needed with rounding
mode being set to RoundingMode.UNNECESSARYFieldPosition
public AttributedCharacterIterator formatToCharacterIterator(Object obj)
AttributedCharacterIterator
.
You can use the returned AttributedCharacterIterator
to build the resulting String, as well as to determine information
about the resulting String.
Each attribute key of the AttributedCharacterIterator will be of type
NumberFormat.Field
, with the attribute value being the
same as the attribute key.
formatToCharacterIterator
in class Format
obj
- The object to format
NullPointerException
- if obj is null.
IllegalArgumentException
- when the Format cannot format the
given object.
ArithmeticException
- if rounding is needed with rounding
mode being set to RoundingMode.UNNECESSARYpublic Number parse(String text, ParsePosition pos)
Number
.
The method attempts to parse text starting at the index given by
pos
.
If parsing succeeds, then the index of pos
is updated
to the index after the last character used (parsing does not necessarily
use all characters up to the end of the string), and the parsed
number is returned. The updated pos
can be used to
indicate the starting point for the next call to this method.
If an error occurs, then the index of pos
is not
changed, the error index of pos
is set to the index of
the character where the error occurred, and null is returned.
The subclass returned depends on the value of isParseBigDecimal()
as well as on the string being parsed.
isParseBigDecimal()
is false (the default),
most integer values are returned as Long
objects, no matter how they are written: "17"
and
"17.000"
both parse to Long(17)
.
Values that cannot fit into a Long
are returned as
Double
s. This includes values with a fractional part,
infinite values, NaN
, and the value -0.0.
DecimalFormat
does not decide whether to
return a Double
or a Long
based on the
presence of a decimal separator in the source string. Doing so
would prevent integers that overflow the mantissa of a double,
such as "-9,223,372,036,854,775,808.00"
, from being
parsed accurately.
Callers may use the Number
methods
doubleValue
, longValue
, etc., to obtain
the type they want.
isParseBigDecimal()
is true, values are returned
as BigDecimal
objects. The values are the ones
constructed by BigDecimal.BigDecimal(String)
for corresponding strings in locale-independent format. The
special cases negative and positive infinity and NaN are returned
as Double
instances holding the values of the
corresponding Double
constants.
DecimalFormat
parses all Unicode characters that represent
decimal digits, as defined by Character.digit()
. In
addition, DecimalFormat
also recognizes as digits the ten
consecutive characters starting with the localized zero digit defined in
the DecimalFormatSymbols
object.
parse
in class NumberFormat
text
- the string to be parsedpos
- A ParsePosition
object with index and error
index information as described above.
null
if the parse fails
NullPointerException
- if text
or
pos
is null.NumberFormat.isParseIntegerOnly()
,
Format.parseObject(java.lang.String, java.text.ParsePosition)
public DecimalFormatSymbols getDecimalFormatSymbols()
DecimalFormatSymbols
public void setDecimalFormatSymbols(DecimalFormatSymbols newSymbols)
newSymbols
- desired DecimalFormatSymbolsDecimalFormatSymbols
public String getPositivePrefix()
Examples: +123, $123, sFr123
public void setPositivePrefix(String newValue)
Examples: +123, $123, sFr123
public String getNegativePrefix()
Examples: -123, ($123) (with negative suffix), sFr-123
public void setNegativePrefix(String newValue)
Examples: -123, ($123) (with negative suffix), sFr-123
public String getPositiveSuffix()
Example: 123%
public void setPositiveSuffix(String newValue)
Example: 123%
public String getNegativeSuffix()
Examples: -123%, ($123) (with positive suffixes)
public void setNegativeSuffix(String newValue)
Examples: 123%
public int getMultiplier()
setMultiplier(int)
public void setMultiplier(int newValue)
Example: with multiplier 100, 1.23 is formatted as "123", and "123" is parsed into 1.23.
getMultiplier()
public int getGroupingSize()
public void setGroupingSize(int newValue)
public boolean isDecimalSeparatorAlwaysShown()
Example: Decimal ON: 12345 -> 12345.; OFF: 12345 -> 12345
public void setDecimalSeparatorAlwaysShown(boolean newValue)
Example: Decimal ON: 12345 -> 12345.; OFF: 12345 -> 12345
public boolean isParseBigDecimal()
parse(java.lang.String, java.text.ParsePosition)
method returns BigDecimal
. The default value is false.
setParseBigDecimal(boolean)
public void setParseBigDecimal(boolean newValue)
parse(java.lang.String, java.text.ParsePosition)
method returns BigDecimal
.
isParseBigDecimal()
public Object clone()
clone
in class NumberFormat
Cloneable
public boolean equals(Object obj)
equals
in class NumberFormat
obj
- the reference object with which to compare.
true
if this object is the same as the obj
argument; false
otherwise.Object.hashCode()
,
Hashtable
public int hashCode()
hashCode
in class NumberFormat
Object.equals(java.lang.Object)
,
Hashtable
public String toPattern()
applyPattern(java.lang.String)
public String toLocalizedPattern()
applyPattern(java.lang.String)
public void applyPattern(String pattern)
There is no limit to integer digits set by this routine, since that is the typical end-user desire; use setMaximumInteger if you want to set a real value. For negative numbers, use a second pattern, separated by a semicolon
Example "#,#00.0#"
-> 1,234.56
This means a minimum of 2 integer digits, 1 fraction digit, and a maximum of 2 fraction digits.
Example: "#,#00.0#;(#,#00.0#)"
for negatives in
parentheses.
In negative patterns, the minimum and maximum counts are ignored; these are presumed to be set in the positive pattern.
NullPointerException
- if pattern
is null
IllegalArgumentException
- if the given pattern is invalid.public void applyLocalizedPattern(String pattern)
There is no limit to integer digits set by this routine, since that is the typical end-user desire; use setMaximumInteger if you want to set a real value. For negative numbers, use a second pattern, separated by a semicolon
Example "#,#00.0#"
-> 1,234.56
This means a minimum of 2 integer digits, 1 fraction digit, and a maximum of 2 fraction digits.
Example: "#,#00.0#;(#,#00.0#)"
for negatives in
parentheses.
In negative patterns, the minimum and maximum counts are ignored; these are presumed to be set in the positive pattern.
NullPointerException
- if pattern
is null
IllegalArgumentException
- if the given pattern is invalid.public void setMaximumIntegerDigits(int newValue)
BigInteger
and
BigDecimal
objects, the lower of newValue
and
309 is used. Negative input values are replaced with 0.
setMaximumIntegerDigits
in class NumberFormat
newValue
- the maximum number of integer digits to be shown; if
less than zero, then zero is used. The concrete subclass may enforce an
upper limit to this value appropriate to the numeric type being formatted.NumberFormat.setMaximumIntegerDigits(int)
public void setMinimumIntegerDigits(int newValue)
BigInteger
and
BigDecimal
objects, the lower of newValue
and
309 is used. Negative input values are replaced with 0.
setMinimumIntegerDigits
in class NumberFormat
newValue
- the minimum number of integer digits to be shown; if
less than zero, then zero is used. The concrete subclass may enforce an
upper limit to this value appropriate to the numeric type being formatted.NumberFormat.setMinimumIntegerDigits(int)
public void setMaximumFractionDigits(int newValue)
BigInteger
and
BigDecimal
objects, the lower of newValue
and
340 is used. Negative input values are replaced with 0.
setMaximumFractionDigits
in class NumberFormat
newValue
- the maximum number of fraction digits to be shown; if
less than zero, then zero is used. The concrete subclass may enforce an
upper limit to this value appropriate to the numeric type being formatted.NumberFormat.setMaximumFractionDigits(int)
public void setMinimumFractionDigits(int newValue)
BigInteger
and
BigDecimal
objects, the lower of newValue
and
340 is used. Negative input values are replaced with 0.
setMinimumFractionDigits
in class NumberFormat
newValue
- the minimum number of fraction digits to be shown; if
less than zero, then zero is used. The concrete subclass may enforce an
upper limit to this value appropriate to the numeric type being formatted.NumberFormat.setMinimumFractionDigits(int)
public int getMaximumIntegerDigits()
BigInteger
and
BigDecimal
objects, the lower of the return value and
309 is used.
getMaximumIntegerDigits
in class NumberFormat
setMaximumIntegerDigits(int)
public int getMinimumIntegerDigits()
BigInteger
and
BigDecimal
objects, the lower of the return value and
309 is used.
getMinimumIntegerDigits
in class NumberFormat
setMinimumIntegerDigits(int)
public int getMaximumFractionDigits()
BigInteger
and
BigDecimal
objects, the lower of the return value and
340 is used.
getMaximumFractionDigits
in class NumberFormat
setMaximumFractionDigits(int)
public int getMinimumFractionDigits()
BigInteger
and
BigDecimal
objects, the lower of the return value and
340 is used.
getMinimumFractionDigits
in class NumberFormat
setMinimumFractionDigits(int)
public Currency getCurrency()
DecimalFormatSymbols.getCurrency
on this number format's symbols.
getCurrency
in class NumberFormat
null
public void setCurrency(Currency currency)
DecimalFormatSymbols.setCurrency
on this number format's symbols.
setCurrency
in class NumberFormat
currency
- the new currency to be used by this decimal format
NullPointerException
- if currency
is nullpublic RoundingMode getRoundingMode()
RoundingMode
used in this DecimalFormat.
getRoundingMode
in class NumberFormat
RoundingMode
used for this DecimalFormat.setRoundingMode(RoundingMode)
public void setRoundingMode(RoundingMode roundingMode)
RoundingMode
used in this DecimalFormat.
setRoundingMode
in class NumberFormat
roundingMode
- The RoundingMode
to be used
NullPointerException
- if roundingMode
is null.getRoundingMode()