Java小数点処理

package com.test;

import java.text.DecimalFormat;

public class FormatTest {

	public static void main(String[] args) {
		System.out.print(formatNum(5.0));
	}

	private static String formatNum(Double d) {
		String formatPattern = "#,##0.000";
		if (d == null) {
			return "-";
		} else {
			if (d == 0) {
				return "-";
			}
			return new DecimalFormat(formatPattern).format(d);
		}
	}
}