将BigDecimal转成字符串为科学计数法的踩坑记录将BigDecimal转成字符串为科学计

BigDecimal转字符串为科学计数法踩坑

场景
解决
案例演示

BigDecimal变科学计数法

BigDecimal转字符串为科学计数法踩坑
场景
在开发工程中，在金额方面都会定义bigdecimal类型，当然有时候也需要将金额转成字符串。我们可能会很自然的写成金额.toString()方法如：

costBudgetEntity.getInitTotalAmount().toString()//获取初始预算金额的字符串

当然当金额过小时，转成字符串，是没有任何问题的，但当金额数值较大时，转成的字符串时科学计数法格式，这往往不是我们想要的格式。

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因此

costBudgetEntity.getInitTotalAmount().toString()//金额为12000000输出的结果为1.2E+7这种的字符串

然后根据这种字符串，无法做一些想要的业务处理

解决
查看BigDecimal的API后，得知有个toPlainString()方法，此方法的返回类型为String ，它返回此BigDecimal对象的字符串表示形式，不需要任何指数。

/*** 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 pointif(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); }

此时，我们在debug查看：

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costBudgetEntity.getInitTotalAmount().toPlainString() //金额为12000000输出的结果为12000000字符串

【将BigDecimal转成字符串为科学计数法的踩坑记录】
案例演示

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BigDecimal变科学计数法阿里OTS存储BigDecimal
当BigDecimal数据大于9,999,999时
后就变成科学计数法了。
如10,000,000 就变为1.0E7
接收端应该注意
也需要用BigDecimal，要是使用Integer接收，就可能出现异常
以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。