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,
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));
}