获取BigDecimal数字的千分位表示，同时保留精度
获取BigDecimal数字的千分位表示，同时保留精度
需求：BigDecimal ----> String
两种方法：
- 自己编写逻辑方法
- 使用 java 提供的 API 来转化
/**
* 转化一：自己拼接
*/
private static void formatMoney2(BigDecimal money) {
DecimalFormat decimalFormat = new DecimalFormat("#,###");
String[] parts = money.toString().split("\\.");
String res = "";
if (parts.length == 2) {
res = decimalFormat.format(money.longValue()) + "." + parts[1];
} else {
res = decimalFormat.format(money.longValue());
}
System.out.printf("%d %50s\n", money.scale(), res);
}
/**
* 转化二：使用 API, java.text.NumberFormat
*/
static void formatMoney(BigDecimal money) {
NumberFormat instance = NumberFormat.getInstance();
instance.setMinimumFractionDigits(money.scale());
System.out.printf("%d %50s\n", money.scale(), instance.format(money));
}
/**
* 测试
*/
@Test
public void t3() {
Integer fl = 0;//保留小数位数
for (; fl < 30; fl++) {
formatMoney(gainBigDecimal(new BigDecimal("0.456"), fl));//注：如果传入数字 0.456，则有精度问题！
formatMoney(gainBigDecimal(new BigDecimal("12.456"), fl));
formatMoney(gainBigDecimal(new BigDecimal("123.456"), fl));
formatMoney(gainBigDecimal(new BigDecimal("1234.456"), fl));
formatMoney(gainBigDecimal(new BigDecimal("1234567890.456"), fl));
System.out.println("-------");
}
}
/**
* 创建数值，设置保留小数位数
*/
public BigDecimal gainBigDecimal(BigDecimal value, Integer scale) {
if (scale != null) {
value = value.setScale(scale, RoundingMode.HALF_UP);
}
return value;
}
测试
0 0
0 12
0 123
0 1,234
0 1,234,567,890
-------
1 0.5
1 12.5
1 123.5
1 1,234.5
1 1,234,567,890.5
-------
2 0.46
2 12.46
2 123.46
2 1,234.46
2 1,234,567,890.46
-------
3 0.456
3 12.456
3 123.456
3 1,234.456
3 1,234,567,890.456
-------
4 0.4560
4 12.4560
4 123.4560
4 1,234.4560
4 1,234,567,890.4560
-------
5 0.45600
5 12.45600
5 123.45600
5 1,234.45600
5 1,234,567,890.45600
-------
6 0.456000
6 12.456000
6 123.456000
6 1,234.456000
6 1,234,567,890.456000
-------
7 0.4560000
7 12.4560000
7 123.4560000
7 1,234.4560000
7 1,234,567,890.4560000
-------
8 0.45600000
8 12.45600000
8 123.45600000
8 1,234.45600000
8 1,234,567,890.45600000
-------
9 0.456000000
9 12.456000000
9 123.456000000
9 1,234.456000000
9 1,234,567,890.456000000
-------
10 0.4560000000
10 12.4560000000
10 123.4560000000
10 1,234.4560000000
10 1,234,567,890.4560000000
-------
11 0.45600000000
11 12.45600000000
11 123.45600000000
11 1,234.45600000000
11 1,234,567,890.45600000000
-------
12 0.456000000000
12 12.456000000000
12 123.456000000000
12 1,234.456000000000
12 1,234,567,890.456000000000
-------
13 0.4560000000000
13 12.4560000000000
13 123.4560000000000
13 1,234.4560000000000
13 1,234,567,890.4560000000000
-------
14 0.45600000000000
14 12.45600000000000
14 123.45600000000000
14 1,234.45600000000000
14 1,234,567,890.45600000000000
-------
15 0.456000000000000
15 12.456000000000000
15 123.456000000000000
15 1,234.456000000000000
15 1,234,567,890.456000000000000
-------
16 0.4560000000000000
16 12.4560000000000000
16 123.4560000000000000
16 1,234.4560000000000000
16 1,234,567,890.4560000000000000
-------
17 0.45600000000000000
17 12.45600000000000000
17 123.45600000000000000
17 1,234.45600000000000000
17 1,234,567,890.45600000000000000
-------
18 0.456000000000000000
18 12.456000000000000000
18 123.456000000000000000
18 1,234.456000000000000000
18 1,234,567,890.456000000000000000
-------
19 0.4560000000000000000
19 12.4560000000000000000
19 123.4560000000000000000
19 1,234.4560000000000000000
19 1,234,567,890.4560000000000000000
-------
20 0.45600000000000000000
20 12.45600000000000000000
20 123.45600000000000000000
20 1,234.45600000000000000000
20 1,234,567,890.45600000000000000000
-------
21 0.456000000000000000000
21 12.456000000000000000000
21 123.456000000000000000000
21 1,234.456000000000000000000
21 1,234,567,890.456000000000000000000
-------
22 0.4560000000000000000000
22 12.4560000000000000000000
22 123.4560000000000000000000
22 1,234.4560000000000000000000
22 1,234,567,890.4560000000000000000000
-------
23 0.45600000000000000000000
23 12.45600000000000000000000
23 123.45600000000000000000000
23 1,234.45600000000000000000000
23 1,234,567,890.45600000000000000000000
-------
24 0.456000000000000000000000
24 12.456000000000000000000000
24 123.456000000000000000000000
24 1,234.456000000000000000000000
24 1,234,567,890.456000000000000000000000
-------
25 0.4560000000000000000000000
25 12.4560000000000000000000000
25 123.4560000000000000000000000
25 1,234.4560000000000000000000000
25 1,234,567,890.4560000000000000000000000
-------
26 0.45600000000000000000000000
26 12.45600000000000000000000000
26 123.45600000000000000000000000
26 1,234.45600000000000000000000000
26 1,234,567,890.45600000000000000000000000
-------
27 0.456000000000000000000000000
27 12.456000000000000000000000000
27 123.456000000000000000000000000
27 1,234.456000000000000000000000000
27 1,234,567,890.456000000000000000000000000
-------
28 0.4560000000000000000000000000
28 12.4560000000000000000000000000
28 123.4560000000000000000000000000
28 1,234.4560000000000000000000000000
28 1,234,567,890.4560000000000000000000000000
-------
29 0.45600000000000000000000000000
29 12.45600000000000000000000000000
29 123.45600000000000000000000000000
29 1,234.45600000000000000000000000000
29 1,234,567,890.45600000000000000000000000000
-------
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