src/main/java/com/rockagen/commons/util/Arith.java
public static float round(final float v,int scale,int roundingMode){
    	if(scale<0){
    		scale=DIV_SCALE;
    	}
    	if(roundingMode<0){
    		roundingMode=ROUNDING_MODE;
    	}
    	BigDecimal b = new BigDecimal(Float.toString(v));
    	BigDecimal one = new BigDecimal("1");
    	return b.divide(one,scale,roundingMode).floatValue();
    }
public static float round(final float v,int scale,int roundingMode){
    	if(scale<0){
    		scale=DIV_SCALE;
    	}
    	if(roundingMode<0){
    		roundingMode=ROUNDING_MODE;
    	}
    	BigDecimal b = new BigDecimal(Float.toString(v));
    	BigDecimal one = new BigDecimal("1");
    	return b.divide(one,scale,roundingMode).floatValue();
    }
random
@param v value
@param scale  scale,default is {@link #DIV_SCALE}
@param roundingMode default is {@link #ROUNDING_MODE}
@return round float