java.text.DecimalFormat#setGroupingSize ( )源码实例Demo

public static void test2(DecimalFormat df) {
	int number = 155566;
	//默认整数部分三个一组，
	System.out.println(number);//输出格式155,566
	//设置每四个一组
	df.setGroupingSize(4);
	System.out.println(df.format(number));//输出格式为15,5566
	DecimalFormatSymbols dfs = DecimalFormatSymbols.getInstance();
	//设置小数点分隔符
	dfs.setDecimalSeparator(';');
	//设置分组分隔符
	dfs.setGroupingSeparator('a');
	df.setDecimalFormatSymbols(dfs);
	System.out.println(df.format(number));//15a5566
	System.out.println(df.format(11.22));//11;22
	//取消分组
	df.setGroupingUsed(false);
	System.out.println(df.format(number));
}
 

private static String[] fileSize(long size) {
    String s = "";
    if (size > 1024) {
        s = "KB";
        size /= 1024;
        if (size > 1024) {
            s = "MB";
            size /= 1024;
        }
    }
    DecimalFormat df = new DecimalFormat();
    df.setGroupingSize(3);
    String[] result = new String[3];
    result[0] = df.format(size);
    result[1] = s;
    return result;
}
 

/**
 * Initialise the abstract graphics document, specifically meant to set the formatter.
 *
 * @param defaultMaxDigits default max digits
 */
public AbstractGraphicsDocument(int defaultMaxDigits) {
	Locale locale = new Locale("en", "US");
	DecimalFormatSymbols decimalSymbols = new DecimalFormatSymbols(locale);
	decimalSymbols.setDecimalSeparator('.');
	formatter = new DecimalFormat();
	formatter.setDecimalFormatSymbols(decimalSymbols);

	// do not group
	formatter.setGroupingSize(0);

	// do not show decimal SEPARATOR if it is not needed
	formatter.setDecimalSeparatorAlwaysShown(false);
	formatter.setGroupingUsed(false);

	// set default number of fraction digits
	formatter.setMaximumFractionDigits(defaultMaxDigits);

	// minimum fraction digits to 0 so they get not rendered if not needed
	formatter.setMinimumFractionDigits(0);
}
 

public static Currency fromConfig(ConfigurationSection config) {
    DecimalFormat format = new DecimalFormat(config.getString("format", "0.00"));

    if (config.getInt("grouping", 0) > 0) {
        DecimalFormatSymbols symbols = format.getDecimalFormatSymbols();
        if (symbols.getDecimalSeparator() == ',') { // French
            symbols.setGroupingSeparator(' ');
        } else {
            symbols.setGroupingSeparator(',');
        }

        String groupingSeparator = config.getString("grouping-separator", null);

        if (!Strings.isNullOrEmpty(groupingSeparator)) {
            symbols.setGroupingSeparator(groupingSeparator.charAt(0));
        }

        String decimalSeparator = config.getString("decimal-separator", ".");

        if (!Strings.isNullOrEmpty(decimalSeparator)) {
            symbols.setDecimalSeparator(decimalSeparator.charAt(0));
        }

        format.setDecimalFormatSymbols(symbols);
        format.setGroupingUsed(true);
        format.setGroupingSize(3);
    }

    return new Currency(
               config.getString("name.singular", "dollar"),
               config.getString("name.plural", "dollars"),
               format,
               config.getString("balance-format", "{1} {2}")
           );
}
 

protected DecimalFormat format() {
	DecimalFormat df = new DecimalFormat();
	df.setMaximumFractionDigits(3);
	df.setMinimumFractionDigits(3);
	DecimalFormatSymbols dfs = df.getDecimalFormatSymbols();
	dfs.setDecimalSeparator((new String(".").charAt(0)));
	df.setDecimalFormatSymbols(dfs);
	df.setGroupingSize(20);
	return df;

}
 

protected cfData defaultExecute( cfSession _session, List<cfData> parameters, DecimalFormatSymbols _dfs )throws cfmRunTimeException{
	double val = getFormatValue( _session, parameters.get(0) );
	DecimalFormat DF = new DecimalFormat("#,###", _dfs);
	DF.setGroupingSize( 3 );
	return new cfStringData( DF.format( val ) );
	
}
 

public void test_setGroupingSize() {
    DecimalFormat df = new DecimalFormat("###0.##", new DecimalFormatSymbols(Locale.ENGLISH));
    df.setGroupingUsed(true);
    df.setGroupingSize(2);
    assertEquals("Value not set", 2, df.getGroupingSize());
    String result = df.format(123);
    assertTrue("Invalid format:" + result, result.equals("1,23"));
}
 

private MathUtils() {
	super();
	format = (DecimalFormat) DecimalFormat.getNumberInstance(Locale.ENGLISH);
	format.setMaximumFractionDigits(3);
	format.setRoundingMode(RoundingMode.HALF_EVEN);
	format.getDecimalFormatSymbols().setDecimalSeparator('.');
	format.setDecimalSeparatorAlwaysShown(false);
	format.setGroupingSize(0);
	doubleRegex = "[-]?[0-9]*\\.?[0-9]+";
}