CalUtil.java 계산을 도와주는 유틸.

큰 수나, 형변환, 부동소수점 등의 문제를 회피하는데 도움이 됩니다.

	import java.math.BigDecimal;
	import java.math.MathContext;
	import java.math.RoundingMode;
	public class CalUtil {
	public static String divideS(Object a, Object b, int scale) {
	return newBigDecimal(a).divide(newBigDecimal(b), scale, RoundingMode.HALF_UP).toPlainString();
	}
	public static Double divideD(Object a, Object b, int scale) {
	return newBigDecimal(a).divide(newBigDecimal(b), scale, RoundingMode.HALF_UP).doubleValue();
	}
	public static Long divideL(Object a, Object b) {
	return newBigDecimal(a).divide(newBigDecimal(b), 0, RoundingMode.HALF_UP).longValue();
	}
	public static Integer divideI(Object a, Object b) {
	return newBigDecimal(a).divide(newBigDecimal(b), 0, RoundingMode.HALF_UP).intValue();
	}
	public static Integer divideIF(Object a, Object b) {
	return newBigDecimal(a).divide(newBigDecimal(b), 0, RoundingMode.FLOOR).intValue();
	}
	public static Double subtractDR(Object a, Object b, int scale) {
	return newBigDecimal(a).subtract(newBigDecimal(b), new MathContext(scale, RoundingMode.HALF_UP)).doubleValue();
	}
	public static int multiplyI(Object a, Object b) {
	return newBigDecimal(a).multiply(newBigDecimal(b)).intValue();
	}
	public static BigDecimal newBigDecimal(Object a) {
	if (a instanceof String) {
	return new BigDecimal((String) a);
	}
	if (a instanceof Long) {
	return new BigDecimal((Long) a);
	}
	if (a instanceof Integer) {
	return new BigDecimal((Integer) a);
	}
	if (a instanceof Float) {
	return new BigDecimal((Float) a);
	}
	if (a instanceof Double) {
	return new BigDecimal((Double) a);
	}
	throw new RuntimeException(a.getClass().getName() + " is not supported.");
	}
	/**
	* 직각 삼각형 아랫변 길이 구하기
	*
	* @param slope 기울기
	* @param hypotenuse 빗변길이
	* @return
	*/
	public static Double getTriangleBaseWidth(Double slope, Double hypotenuse) {
	return Math.abs(CalUtil.divideD(hypotenuse, Math.sqrt(Math.pow(slope, 2) + 1), 8));
	}
	/**
	* 직각 삼각형 높이 길이 구하기
	*
	* @param slope 기울기
	* @param hypotenuse 빗변길이
	* @return
	*/
	public static Double getTriangleHeight(Double slope, Double hypotenuse) {
	return Math.abs(CalUtil.divideD(hypotenuse * slope, Math.sqrt(Math.pow(slope, 2) + 1), 8));
	}
	}

view raw CalUtil.java hosted with ❤ by GitHub