This
class formats and parses numbers in a locale-specific way. As an
abstract class, it cannot be instantiated directly, but it provides a
number of static methods that return instances of a concrete subclass
you can use for formatting. The getInstance( )
method returns a NumberFormat object suitable for
normal formatting of numbers in either the default locale or in a
specified locale. getIntegerInstance( ),
getCurrencyInstance( ), and
getPercentInstance( ) return
NumberFormat objects for formatting numbers that
are integers, or represent monetary amounts or
percentages.
These methods return a NumberFormat suitable for
the default locale, or for the specified Locale
object. getAvailableLocales( ) returns an array of
locales for which NumberFormat objects are
available. In Java 1.4 and later, use setCurrency(
) to provide a java.util.Currency object
for use when formating monetary values. Note that the
NumberFormat class is not intended for the display
of very large or very small numbers that require exponential
notation, and it may not gracefully handle infinite or
NaN (not-a-number) values.
Once you have created a suitable
NumberFormat object, you can customize its
localeindependent behavior with setMaximumFractionDigits(
), setGroupingUsed( ), and similar
set methods. In order to customize the
locale-dependent behavior, you can use instanceof
to test if the NumberFormat object is an instance
of DecimalFormat, and, if so, cast it to that
type. The DecimalFormat class provides complete
control over number formatting. Note, however, that a
NumberFormat customized in this way may no longer
be appropriate for the desired locale.
After creating and customizing a
NumberFormat object, you can use the various
format( ) methods to convert numbers to strings or
string buffers, and you can use the parse( ) or
parseObject( ) methods to convert strings to
numbers. You can also use the formatToCharacterIterator(
) method inherited from Format (and
overridden by DecimalFormat) in place of
format( ). The constants defined by this class are
to be used by the FieldPosition object.
public abstract class NumberFormat extends Format {
// Public Constructors
public NumberFormat( );
// Public Constants
public static final int FRACTION_FIELD; =1
public static final int INTEGER_FIELD; =0
// Nested Types
1.4 public static class Field extends Format.Field;
// Public Class Methods
public static java.util.Locale[ ] getAvailableLocales( );
public static final NumberFormat getCurrencyInstance( );
public static NumberFormat getCurrencyInstance(java.util.Locale inLocale);
public static final NumberFormat getInstance( );
public static NumberFormat getInstance(java.util.Locale inLocale);
1.4 public static final NumberFormat getIntegerInstance( );
1.4 public static NumberFormat getIntegerInstance(java.util.Locale inLocale);
public static final NumberFormat getNumberInstance( );
public static NumberFormat getNumberInstance(java.util.Locale inLocale);
public static final NumberFormat getPercentInstance( );
public static NumberFormat getPercentInstance(java.util.Locale inLocale);
// Public Instance Methods
public final String format(long number);
public final String format(double number);
public abstract StringBuffer format(long number, StringBuffer toAppendTo,
FieldPosition pos);
public abstract StringBuffer format(double number, StringBuffer toAppendTo,
FieldPosition pos);
1.4 public java.util.Currency getCurrency( );
public int getMaximumFractionDigits( );
public int getMaximumIntegerDigits( );
public int getMinimumFractionDigits( );
public int getMinimumIntegerDigits( );
public boolean isGroupingUsed( );
public boolean isParseIntegerOnly( );
public Number parse(String source) throws ParseException;
public abstract Number parse(String source, ParsePosition parsePosition);
1.4 public void setCurrency(java.util.Currency currency);
public void setGroupingUsed(boolean newValue);
public void setMaximumFractionDigits(int newValue);
public void setMaximumIntegerDigits(int newValue);
public void setMinimumFractionDigits(int newValue);
public void setMinimumIntegerDigits(int newValue);
public void setParseIntegerOnly(boolean value);
// Public Methods Overriding Format
public Object clone( );
public StringBuffer format(Object number, StringBuffer toAppendTo,
FieldPosition pos);
public final Object parseObject(String source, ParsePosition pos);
// Public Methods Overriding Object
public boolean equals(Object obj);
public int hashCode( );
}
