Java 检查 BigDecimal 值是否在范围内
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Check if BigDecimal value is in range
提问by user3127896
I have BiGDecimal priceand i need to check if it is in some range.
For example should be 3 conditions:
我有BiGDecimal price，我需要检查它是否在某个范围内。例如应该是3个条件：
if (price >= 0 and price <=500) {
....
} else if (price >=500 && price <=1000) {
....
} else if (price > 1000) {
....
}
How to do it right using BigDecimal type.
如何正确使用 BigDecimal 类型。
采纳答案by Anders R. Bystrup
That is achievable using the .compareTo()method. For instance:
这可以使用.compareTo()方法实现。例如：
if ( price.compareTo( BigDecimal.valueOf( 500 ) > 0
&& price.compareTo( BigDecimal.valueOf( 1000 ) < 0 ) {
// price is larger than 500 and less than 1000
...
}
Quoting (and paraphrasing) from the JavaDoc:
从 JavaDoc 引用（和释义）：
The suggested idiom for performing these comparisons is: (x.compareTo(y) op0), where opis one of the six comparison operators [(<, ==, >, >=, !=, <=)]
执行这些比较的建议习惯用法是：(x.compareTo(y) op0)，其中op是六个比较运算符之一[(<, ==, >, >=, !=, <=)]
Cheers,
干杯，
回答by Simulant
Use BigDecimal.compareTo(val)to compare if your Number is bigger, smaller or equal.
使用BigDecimal.compareTo(val)比较，如果你的号码是更大，更小或相等。
returns -1, 0, or 1 as this BigDecimal is numerically less than, equal to, or greater than val.
返回 -1、0 或 1，因为此 BigDecimal 在数字上小于、等于或大于 val。
if (price.compareTo(BigDecimal.ZERO) >= 0 &&
price.compareTo(new BigDecimal(500)) <= 0) {
....
} else if (price.compareTo(new BigDecimal(500)) >= 0 &&
price.compareTo(new BigDecimal(1000)) <= 0) {
....
} else if (price.compareTo(price.compareTo(new BigDecimal(1000)) < 0) {
....
}
回答by Prabhu R.D
use compareTo method
使用 compareTo 方法
java.math.BigDecimal.compareTo(BigDecimal val)
java.math.BigDecimal.compareTo(BigDecimal val)
This method returns -1 if the BigDecimal is less than val, 1 if the BigDecimal is greater than val and 0 if the BigDecimal is equal to val
如果 BigDecimal 小于 val，则此方法返回 -1；如果 BigDecimal 大于 val，则返回 1；如果 BigDecimal 等于 val，则返回 0
回答by Beri
There is no workaround to this i think. Eventually you could wrap it into a nice design pattern, but BigDecimal has only one method for comparing.
我认为没有解决方法。最终，您可以将其包装成一个不错的设计模式，但 BigDecimal 只有一种比较方法。
My idea is to extract a method for range:
我的想法是提取范围的方法：
boolean isBetween(BigDecimal price, BigDecimal start, BigDecimal end){
return price.compareTo(start) > 0 && price.compareTo(end) < 0;
}
回答by Semih Eker
You can do sthg like this;
你可以这样做；
public class BigDecimalDemo {
public static void main(String[] args) {
// create 2 BigDecimal objects
BigDecimal bg1, bg2;
bg1 = new BigDecimal("10");
bg2 = new BigDecimal("20");
//create int object
int res;
res = bg1.compareTo(bg2); // compare bg1 with bg2
String str1 = "Both values are equal ";
String str2 = "First Value is greater ";
String str3 = "Second value is greater";
if( res == 0 )
System.out.println( str1 );
else if( res == 1 )
System.out.println( str2 );
else if( res == -1 )
System.out.println( str3 );
}
}
resource : http://www.tutorialspoint.com/java/math/bigdecimal_compareto.htm
资源：http: //www.tutorialspoint.com/java/math/bigdecimal_compareto.htm
回答by dani77
Use signum method from BigDecimal class:
使用 BigDecimal 类中的 signum 方法：
private static boolean isBetween(BigDecimal amount, BigDecimal init, BigDecimal end) {
return amount.subtract(init).signum() >= 0 && amount.subtract(end).signum() <= 0;
}
回答by Kirill Karandin
Lets make it generic:
让我们让它通用：
public static <T extends Comparable<T>> boolean isBetween(T value, T start, T end) {
return value.compareTo(start) >= 0 && value.compareTo(end) <= 0;
}
回答by Luigi Scognamiglio
As said by Kirill Karandin, you can write a generic method:
正如 Kirill Karandin 所说，您可以编写一个泛型方法：
public static <T extends Comparable<T>> boolean isBetween(T x, T lowerBound, T upperBound) {
return (x.compareTo(lowerBound) + upperBound.compareTo(x)) > 0;
}
The difference is that the inner sum will return:
不同之处在于内部总和将返回：
- 0, if x is either less than of min or greater than of max;
- 1, if x is equal to either min or max;
- 2, if x belong to the interval, but it's not equal to either min or max.
- 0，如果 x 小于 min 或大于 max；
- 1，如果 x 等于 min 或 max；
- 2、如果x属于区间，但既不等于min也不等于max。
Consequently, if the sum is greater than of 0 (or simply not equal to 0) the x variable will belong to the interval.
因此，如果总和大于 0（或简单地不等于 0），则 x 变量将属于该区间。
回答by beat
If you already use Apache commons lang, one option is to use the Rangeclass instead of writing your own utility method:
如果您已经使用 Apache commons lang，一种选择是使用Range类而不是编写您自己的实用程序方法：
@Test
public void bigDecimalInRange() {
Range<BigDecimal> myRange = Range.between(BigDecimal.TEN, BigDecimal.valueOf(300));
BigDecimal tooSmallAmount = new BigDecimal("2.50");
assertFalse(myRange.contains(tooSmallAmount));
BigDecimal rightAmount = new BigDecimal("10.01");
assertTrue(myRange.contains(rightAmount));
}
回答by Johan Sebastian Navarro Cano
BigDecimal value = BigDecimal.valueOf(2);
BigDecimal zero = BigDecimal.valueOf(0);
BigDecimal one = BigDecimal.valueOf(1);
// When it is greater than 0 it returns 1 or if it is equal to 0 it returns 0
System.out.println(value.compareTo(BigDecimal.ZERO)>=0);
// When it is greater than 1 it returns -1 or if it is equal to 1 it returns 0
System.out.println(value.compareTo(BigDecimal.ONE)<=0);
boolean condition = value.compareTo(BigDecimal.ZERO) >= 0 && value.compareTo(BigDecimal.ONE) <= 0;
System.out.println(condition);
