数字と日付の書式フォーマット

Google Web Toolkitの数値と日付の書式フォーマット機能を紹介します。

サンプル

Webtestsample.java
public String GetShowContent()
{
    GWT.log("helo GWT log.");

    StringBuilder content = new StringBuilder();
   
    NumberFormat fmt = NumberFormat.getDecimalFormat();
    double value = 12345.6789;
    String formatted = fmt.format(value);
    content.append("Formatted string is" + formatted + "<br/>");
   
    value = NumberFormat.getDecimalFormat().parse("12345.6789");
    content.append("Parsed value is" + value + "<br/>");
   
    value = 12345.6789;
    formatted = NumberFormat.getScientificFormat().format(value);
    content.append("Formatted string is" + formatted + "<br/>");
   
    value = 12345.6789;
    formatted = NumberFormat.getFormat("000000.000000").format(value);
    content.append("Formatted string is" + formatted + "<br/>");
   
    Date today = new Date();

    // prints Tue Dec 18 12:01:26 GMT-500 2007 in the default locale.
    content.append(today.toString() + "<br/>");

    content.append(DateTimeFormat.getFormat("yyyy年MM月dd日").format(today) + "<br/>");
   
    // prints 12/18/07 in the default locale
    content.append(DateTimeFormat.getShortDateFormat().format(today) + "<br/>");

    // prints December 18, 2007 in the default locale
    content.append(DateTimeFormat.getLongDateFormat().format(today) + "<br/>");

    // prints 12:01 PM in the default locale
    content.append(DateTimeFormat.getShortTimeFormat().format(today) + "<br/>");

    // prints 12:01:26 PM GMT-05:00 in the default locale
    content.append(DateTimeFormat.getLongTimeFormat().format(today) + "<br/>");

    // prints Dec 18, 2007 12:01:26 PM in the default locale
    content.append(DateTimeFormat.getMediumDateTimeFormat().format(today) + "<br/>");
   
    return content.toString();
}
一部のコードを省略します…

なお、DateTimeFormatクラスの仕様詳細をこちらにご参照ください。
http://google-web-toolkit.googlecode.com/svn/javadoc/2.0/com/google/gwt/i18n/client/DateTimeFormat.html