BigDecimal去掉小数点后无用的0

如题:BigDecimal去掉小数点后无用的0

比如:数据库存储的是Decimal(5,2)类型保留两位数。
如果展示数据5.00,5.10等字样感觉很不爽,如何做呢?
只战术5和5.1

解决:BigDecimal,有方法解决stripTrailingZeros()

看源码:



/**
     * Returns a string representation of this {@code BigDecimal}
     * without an exponent field.  For values with a positive scale,
     * the number of digits to the right of the decimal point is used
     * to indicate scale.  For values with a zero or negative scale,
     * the resulting string is generated as if the value were
     * converted to a numerically equal value with zero scale and as
     * if all the trailing zeros of the zero scale value were present
     * in the result.
     *
     * The entire string is prefixed by a minus sign character '-'
     * ('\u002D') if the unscaled value is less than
     * zero. No sign character is prefixed if the unscaled value is
     * zero or positive.
     *
     * Note that if the result of this method is passed to the
     * {@linkplain #BigDecimal(String) string constructor}, only the
     * numerical value of this {@code BigDecimal} will necessarily be
     * recovered; the representation of the new {@code BigDecimal}
     * may have a different scale.  In particular, if this
     * {@code BigDecimal} has a negative scale, the string resulting
     * from this method will have a scale of zero when processed by
     * the string constructor.
     *
     * (This method behaves analogously to the {@code toString}
     * method in 1.4 and earlier releases.)
     *
     * @return a string representation of this {@code BigDecimal}
     * without an exponent field.
     * @since 1.5
     * @see #toString()
     * @see #toEngineeringString()
     */
    public String toPlainString() {
        if(scale==0) {
            if(intCompact!=INFLATED) {
                return Long.toString(intCompact);
            } else {
                return intVal.toString();
            }
        }
        if(this.scale<0) { // No decimal point
            if(signum()==0) {
                return "0";
            }
            int tailingZeros = checkScaleNonZero((-(long)scale));
            StringBuilder buf;
            if(intCompact!=INFLATED) {
                buf = new StringBuilder(20+tailingZeros);
                buf.append(intCompact);
            } else {
                String str = intVal.toString();
                buf = new StringBuilder(str.length()+tailingZeros);
                buf.append(str);
            }
            for (int i = 0; i < tailingZeros; i++)
                buf.append('0');
            return buf.toString();
        }
        String str ;
        if(intCompact!=INFLATED) {
            str = Long.toString(Math.abs(intCompact));
        } else {
            str = intVal.abs().toString();
        }
        return getValueString(signum(), str, scale);
    }
 /**
     * Returns a {@code BigDecimal} which is numerically equal to
     * this one but with any trailing zeros removed from the
     * representation.  For example, stripping the trailing zeros from
     * the {@code BigDecimal} value {@code 600.0}, which has
     * [{@code BigInteger}, {@code scale}] components equals to
     * [6000, 1], yields {@code 6E2} with [{@code BigInteger},
     * {@code scale}] components equals to [6, -2].  If
     * this BigDecimal is numerically equal to zero, then
     * {@code BigDecimal.ZERO} is returned.
     *
     * @return a numerically equal {@code BigDecimal} with any
     * trailing zeros removed.
     * @since 1.5
     */
    public BigDecimal stripTrailingZeros() {
        if (intCompact == 0 || (intVal != null && intVal.signum() == 0)) {
            return BigDecimal.ZERO;
        } else if (intCompact != INFLATED) {
            return createAndStripZerosToMatchScale(intCompact, scale, Long.MIN_VALUE);
        } else {
            return createAndStripZerosToMatchScale(intVal, scale, Long.MIN_VALUE);
        }
    }

demo

public class StringUtils {

    public static void main(String[] args) {
        System.out.println(BigDecimal.ZERO);
        System.out.println(new BigDecimal("2.0"));
        System.out.println(new Double("0"));
        System.out.println(new BigDecimal("2.00"));
        String d = new BigDecimal("100.10").stripTrailingZeros().toPlainString();
        System.out.println(d);
        System.out.println(new BigDecimal("100.10").stripTrailingZeros().toPlainString());
    }
}

结果:
BigDecimal去掉小数点后无用的0_第1张图片

方法二:

 private static final DecimalFormat decimalFormat = new DecimalFormat("###################.###########");

    public static void main(String[] args) throws Exception{
        System.out.print( "格式化结果:");
        System.out.println(decimalFormat.format(new BigDecimal("10.10")));
    }

结果:
BigDecimal去掉小数点后无用的0_第2张图片

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