BigDecimail 转为负数

 BigDecimail 转负数negate()

new BigDecimail().negate()     返回负数

 

源码：

 /**
     * Returns a {@code BigDecimal} whose value is {@code (-this)},
     * and whose scale is {@code this.scale()}.
     *
     * @return {@code -this}.
     */
    public BigDecimal negate() {
        if (intCompact == INFLATED) {
            return new BigDecimal(intVal.negate(), INFLATED, scale, precision);
        } else {
            return valueOf(-intCompact, scale, precision);
        }
    }
 

 /**
     * Trusted package private constructor.
     * Trusted simply means if val is INFLATED, intVal could not be null and
     * if intVal is null, val could not be INFLATED.
     */
    BigDecimal(BigInteger intVal, long val, int scale, int prec) {
        this.scale = scale;
        this.precision = prec;
        this.intCompact = val;
        this.intVal = intVal;
    }

/**
     * Translates a {@code long} value into a {@code BigDecimal}
     * with a scale of zero.  This {@literal "static factory method"}
     * is provided in preference to a ({@code long}) constructor
     * because it allows for reuse of frequently used
     * {@code BigDecimal} values.
     *
     * @param val value of the {@code BigDecimal}.
     * @return a {@code BigDecimal} whose value is {@code val}.
     */
 static BigDecimal valueOf(long unscaledVal, int scale, int prec) {
        if (scale == 0 && unscaledVal >= 0 && unscaledVal < zeroThroughTen.length) {
            return zeroThroughTen[(int) unscaledVal];
        } else if (unscaledVal == 0) {
            return zeroValueOf(scale);
        }
        return new BigDecimal(unscaledVal == INFLATED ? INFLATED_BIGINT : null,
                unscaledVal, scale, prec);
    }

 /**
     * Sentinel value for {@link #intCompact} indicating the
     * significand information is only available from {@code intVal}.
     */
    static final long INFLATED = Long.MIN_VALUE;

/**
     * A constant holding the minimum value a {@code long} can
     * have, -263.
     */
    @Native public static final long MIN_VALUE = 0x8000000000000000L;