Class java.text.ChoiceFormat
java.lang.Object
|
+----java.text.Format
|
+----java.text.NumberFormat
|
+----java.text.ChoiceFormat
- public class ChoiceFormat
- extends NumberFormat
A ChoiceFormat
allows you to attach a format to a range of numbers.
It is generally used in a MessageFormat
for handling plurals.
The choice is specified with an ascending list of doubles, where each item
specifies a half-open interval up to the next item:
X matches j if and only if limit[j] <= X < limit[j+1]
If there is no match, then either the first or last index is used, depending
on whether the number (X) is too low or too high.
Note:
ChoiceFormat
differs from the other Format
classes in that you create a ChoiceFormat
object with a
constructor (not with a getInstance
style factory
method). The factory methods aren't necessary because ChoiceFormat
doesn't require any complex setup for a given locale. In fact,
ChoiceFormat
doesn't implement any locale specific behavior.
When creating a ChoiceFormat
, you must specify an array of formats
and an array of limits. The length of these arrays must be the same.
For example,
-
limits = {1,2,3,4,5,6,7}
formats = {"Sun","Mon","Tue","Wed","Thur","Fri","Sat"}
-
limits = {0, 1, ChoiceFormat.nextDouble(1)}
formats = {"no files", "one file", "many files"}
(nextDouble
can be used to get the next higher double, to
make the half-open interval.)
Here is a simple example that shows formatting and parsing:
double[] limits = {1,2,3,4,5,6,7};
String[] monthNames = {"Sun","Mon","Tue","Wed","Thur","Fri","Sat"};
ChoiceFormat form = new ChoiceFormat(limits, monthNames);
ParsePosition status = new ParsePosition(0);
for (double i = 0.0; i <= 8.0; ++i) {
status.setIndex(0);
System.out.println(i + " -> " + form.format(i) + " -> "
+ form.parse(form.format(i),status));
}
Here is a more complex example, with a pattern format:
double[] filelimits = {0,1,2};
String[] filepart = {"are no files","is one file","are {2} files"};
ChoiceFormat fileform = new ChoiceFormat(filelimits, filepart);
Format[] testFormats = {fileform, null, NumberFormat.getInstance()};
MessageFormat pattform = new MessageFormat("There {0} on {1}");
pattform.setFormats(testFormats);
Object[] testArgs = {null, "ADisk", null};
for (int i = 0; i < 4; ++i) {
testArgs[0] = new Integer(i);
testArgs[2] = testArgs[0];
System.out.println(pattform.format(testArgs));
}
- See Also:
- DecimalFormat, MessageFormat
Constructor Summary
|
ChoiceFormat(String newPattern)
Constructs with limits and corresponding formats based on the pattern.
|
ChoiceFormat(double[] limits,
String[] formats)
Constructs with the limits and the corresponding formats.
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Methods inherited from class java.text.NumberFormat
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clone, equals, format, format, format, format, format, getAvailableLocales, getCurrencyInstance, getCurrencyInstance, getInstance, getInstance, getMaximumFractionDigits, getMaximumIntegerDigits, getMinimumFractionDigits, getMinimumIntegerDigits, getNumberInstance, getNumberInstance, getPercentInstance, getPercentInstance, hashCode, isGroupingUsed, isParseIntegerOnly, parse, parse, parseObject, setGroupingUsed, setMaximumFractionDigits, setMaximumIntegerDigits, setMinimumFractionDigits, setMinimumIntegerDigits, setParseIntegerOnly |
Methods inherited from class java.lang.Object
|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
ChoiceFormat
public ChoiceFormat(String newPattern)
- Constructs with limits and corresponding formats based on the pattern.
ChoiceFormat
public ChoiceFormat(double[] limits,
String[] formats)
- Constructs with the limits and the corresponding formats.
- See Also:
- setChoices
applyPattern
public void applyPattern(String newPattern)
- Sets the pattern.
- Parameters:
newPattern
- See the class description.
toPattern
public String toPattern()
- Gets the pattern.
setChoices
public void setChoices(double[] limits,
String[] formats)
- Set the choices to be used in formatting.
- Parameters:
limits
- contains the top value that you want
parsed with that format,and should be in ascending sorted order. When
formatting X, the choice will be the i, where limit[i] <= X < limit[i+1].
formats
- are the formats you want to use for each limit.
They can be either Format objects or Strings.
When formatting with object Y,
if the object is a NumberFormat, then ((NumberFormat) Y).format(X)
is called. Otherwise Y.toString() is called.
getLimits
public double[] getLimits()
- Get the limits passed in the constructor.
- Returns:
- the limits.
getFormats
public Object[] getFormats()
- Get the formats passed in the constructor.
- Returns:
- the formats.
format
public StringBuffer format(long number,
StringBuffer toAppendTo,
FieldPosition status)
- Specialization of format. This method really calls
format(double, StringBuffer, FieldPosition)
thus the range of longs that are supported is only equal to
the range that can be stored by double. This will never be
a practical limitation.
- Overrides:
- format in class NumberFormat
format
public StringBuffer format(double number,
StringBuffer toAppendTo,
FieldPosition status)
- Overrides:
- format in class NumberFormat
parse
public Number parse(String text,
ParsePosition status)
- Overrides:
- parse in class NumberFormat
nextDouble
public static final double nextDouble(double d)
- Finds the least double greater than d.
If NaN, returns same value.
Used to make half-open intervals.
- See Also:
- previousDouble
previousDouble
public static final double previousDouble(double d)
- Finds the greatest double less than d.
If NaN, returns same value.
- See Also:
- nextDouble
clone
public Object clone()
- Overrides Cloneable
- Overrides:
- clone in class NumberFormat
hashCode
public int hashCode()
- Generates a hash code for the message format object.
- Overrides:
- hashCode in class NumberFormat
equals
public boolean equals(Object obj)
- Equality comparision between two
- Overrides:
- equals in class NumberFormat
nextDouble
public static double nextDouble(double d,
boolean positive)
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