保留四捨五入後的兩位小數

import java.math.RoundingMode;
import java.text.DecimalFormat;

public class DoubleFormat {

	/**
	 * Keep the two decimal point
	 * @return
	 */
	/*public static Double change2DeciemalPoint(double dou){
		NumberFormat format = DecimalFormat.getInstance();
		format.setMaximumFractionDigits(2);
		return Double.parseDouble(format.format(dou));
		
	}*/
	static DecimalFormat df = new DecimalFormat("##.00");
	
	static{
		df.setRoundingMode(RoundingMode.HALF_UP);
	}
	
	public static Double change2DeciemalPoint(double dou){
		return new Double(df.format(dou));
		
	}
	
	/*public static void main(String[] args) {
		System.out.println(change2DeciemalPoint(10000000000.335d));
	}*/
}