BigDecimal处理四舍五入

import java.math.BigDecimal;

public class Test {

	public static void main(String args[]) {
		Test test = new Test();
		double hehe=test.toDouble2(10000.0*1000000000/(1220.0*2440.0*3.0));
		System.out.println(hehe);
	}
	
	public double toDouble2(double dou) {
		System.out.println(dou);
	    BigDecimal bd = new BigDecimal(dou);
	    System.out.println(bd);
	    BigDecimal bd1 = bd.setScale(2, BigDecimal.ROUND_HALF_UP);
	    System.out.println(bd1);
	    dou = bd1.doubleValue();
	    return dou;
	  }

}