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Object
|
+----Format
|
+----java.text.NumberFormat
NumberFormat is the abstract base class for all number
formats. This class provides the interface for formatting and parsing
numbers. NumberFormat also provides methods for determining
which locales have number formats, and what their names are.
NumberFormat helps you to format and parse numbers for any locale.
Your code can be completely independent of the locale conventions for
decimal points, thousands-separators, or even the particular decimal
digits used, or whether the number format is even decimal.
To format a number for the current Locale, use one of the factory class methods:
If you are formatting multiple numbers, it is more efficient to get the format and use it multiple times so that the system doesn't have to fetch the information about the local language and country conventions multiple times.myString = NumberFormat.getInstance().format(myNumber);
NumberFormat nf = NumberFormat.getInstance();
for (int i = 0; i < a.length; ++i) {
output.println(nf.format(myNumber[i]) + "; ");
}
To format a number for a different Locale, specify it in the
call to getInstance.
You can also use aNumberFormat nf = NumberFormat.getInstance(Locale.FRENCH);
NumberFormat to parse numbers:
UsemyNumber = nf.parse(myString);
getInstance or getNumberInstance to get the
normal number format. Use getCurrencyInstance to get the
currency number format. And use getPercentInstance to get a
format for displaying percentages. With this format, a fraction like
0.53 is displayed as 53%.
You can also control the display of numbers with such methods as
setMinimumFractionDigits.
If you want even more control over the format or parsing,
or want to give your users more control,
you can try casting the NumberFormat you get from the factory methods
to a DecimalNumberFormat. This will work for the vast majority
of locales; just remember to put it in a try block in case you
encounter an unusual one.
NumberFormat and DecimalFormat are designed such that some controls work for formatting and others work for parsing. The following is the detailed description for each these control methods,
setParseIntegerOnly : only affects parsing, e.g. if true, "3456.78" -> 3456 (and leaves the parse position just after index 6) if false, "3456.78" -> 3456.78 (and leaves the parse position just after index 8) This is independent of formatting. If you want to not show a decimal point where there might be no digits after the decimal point, use setDecimalSeparatorAlwaysShown.
setDecimalSeparatorAlwaysShown : only affects formatting, and only where there might be no digits after the decimal point, such as with a pattern like "#,##0.##", e.g., if true, 3456.00 -> "3,456." if false, 3456.00 -> "3456" This is independent of parsing. If you want parsing to stop at the decimal point, use setParseIntegerOnly.
You can also use forms of the parse and format
methods with ParsePosition and FieldPosition to
allow you to:
FieldPosition in your format call, with
field = INTEGER_FIELD. On output,
getEndIndex will be set to the offset between the
last character of the integer and the decimal. Add
(desiredSpaceCount - getEndIndex) spaces at the front of the string.
getEndIndex.
Then move the pen by
(desiredPixelWidth - widthToAlignmentPoint) before drawing the text.
It also works where there is no decimal, but possibly additional
characters at the end, e.g. with parentheses in negative
numbers: "(12)" for -12.
FRACTION_FIELD
INTEGER_FIELD
java.text.NumberFormat()
clone()
equals(Object)
format(Object, StringBuffer, FieldPosition)
format(double)
format(long)
format(double, StringBuffer, FieldPosition)
format(long, StringBuffer, FieldPosition)
getAvailableLocales()
getCurrencyInstance()
getCurrencyInstance(Locale)
getInstance()
getInstance(Locale)
getMaximumFractionDigits()
getMaximumIntegerDigits()
getMinimumFractionDigits()
getMinimumIntegerDigits()
getNumberInstance()
getNumberInstance(Locale)
getPercentInstance()
getPercentInstance(Locale)
hashCode()
isGroupingUsed()
isParseIntegerOnly()
parse(String, ParsePosition)
parse(String)
parseObject(String, ParsePosition)
setGroupingUsed(boolean)
setMaximumFractionDigits(int)
setMaximumIntegerDigits(int)
setMinimumFractionDigits(int)
setMinimumIntegerDigits(int)
setParseIntegerOnly(boolean)
FRACTION_FIELD
public static final int FRACTION_FIELD
INTEGER_FIELD
public static final int INTEGER_FIELD
NumberFormat
public NumberFormat()
clone
public java.lang.Object clone()
equals
public boolean equals(Object obj)
format
public final java.lang.StringBuffer format(Object number,
StringBuffer toAppendTo,
FieldPosition pos)
format
public final java.lang.String format(double number)
format
public final java.lang.String format(long number)
format
public abstract java.lang.StringBuffer format(double number,
StringBuffer toAppendTo,
FieldPosition pos)
format
public abstract java.lang.StringBuffer format(long number,
StringBuffer toAppendTo,
FieldPosition pos)
getAvailableLocales
public static java.util.Locale[] getAvailableLocales()
getCurrencyInstance
public static final java.text.NumberFormat getCurrencyInstance()
getCurrencyInstance
public static java.text.NumberFormat getCurrencyInstance(Locale inLocale)
getInstance
public static final java.text.NumberFormat getInstance()
getInstance
public static java.text.NumberFormat getInstance(Locale inLocale)
getMaximumFractionDigits
public int getMaximumFractionDigits()
getMaximumIntegerDigits
public int getMaximumIntegerDigits()
getMinimumFractionDigits
public int getMinimumFractionDigits()
getMinimumIntegerDigits
public int getMinimumIntegerDigits()
getNumberInstance
public static final java.text.NumberFormat getNumberInstance()
getNumberInstance
public static java.text.NumberFormat getNumberInstance(Locale inLocale)
getPercentInstance
public static final java.text.NumberFormat getPercentInstance()
getPercentInstance
public static java.text.NumberFormat getPercentInstance(Locale inLocale)
hashCode
public int hashCode()
isGroupingUsed
public boolean isGroupingUsed()
isParseIntegerOnly
public boolean isParseIntegerOnly()
parse
public abstract java.lang.Number parse(String text,
ParsePosition parsePosition)
parse
public java.lang.Number parse(String text) throws ParseException
parseObject
public final java.lang.Object parseObject(String source,
ParsePosition parsePosition)
setGroupingUsed
public void setGroupingUsed(boolean newValue)
setMaximumFractionDigits
public void setMaximumFractionDigits(int newValue)
setMaximumIntegerDigits
public void setMaximumIntegerDigits(int newValue)
setMinimumFractionDigits
public void setMinimumFractionDigits(int newValue)
setMinimumIntegerDigits
public void setMinimumIntegerDigits(int newValue)
setParseIntegerOnly
public void setParseIntegerOnly(boolean value)
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