testdecimalformat.java

本书是一本为Java学习者在基础内容学习结束后进行课程设计时提供参考的指导书

package apibook.c2.s2;

import java.text.*;
import java.util.*;

//测试DecimalFormat类
//功能：输出区域化的数字，整数，货币和百分数
public class TestDecimalFormat {
  public TestDecimalFormat() {
  }
  public static void main(String[] args) {
    //获得区域化配置
    Locale[] locales = NumberFormat.getAvailableLocales();
    double myNumber = -1234.56;//定义测试数字
    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; // 跳过相同语言
            }
            System.out.print(locales[i].getDisplayName());//获取区域名字
            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) {//数字
                System.out.print(": " + ((DecimalFormat) form).toPattern());
            }
            System.out.print(" -> " + form.format(myNumber));//格式化以后
            try {
                System.out.println(" -> " + form.parse(form.format(myNumber)));
            } catch (ParseException e) {}
        }
    }
  }

}