Java LongMath.checkedMultiply(int a, int b)用法及代码示例

CheckedMultiply(long a，long b)是Guava LongMath类的方法，该方法接受两个参数a和b并返回其乘积。

用法:

public static long checkedMultiply(long a, long b)

参数：该方法接受两个long值a和b并计算其乘积。

返回值：该方法返回传递给它的long值的乘积，前提是它不会溢出。

异常：如果乘积(a-b)在有符号的long算术中溢出，则checkedMultiply(long a，long b)方法将引发ArithmeticException。

以下示例说明了上述方法的实现：

范例1：

// Java code to show implementation of 
// checkedMultiply(long a, long b) method 
// of Guava's LongMath class 
  
import java.math.RoundingMode; 
import com.google.common.math.LongMath; 
  
class GFG { 
  
    // Driver code 
    public static void main(String args[]) 
    { 
        long a1 = 25; 
        long b1 = 36; 
  
        // Using checkedMultiply(long a, long b) 
        // method of Guava's LongMath class 
        long ans1 = LongMath.checkedMultiply(a1, b1); 
  
        System.out.println("Product of " + a1 + " and "
                           + b1 + " is:" + ans1); 
  
        long a2 = 150; 
        long b2 = 667; 
  
        // Using checkedMultiply(long a, long b) 
        // method of Guava's LongMath class 
        long ans2 = LongMath.checkedMultiply(a2, b2); 
  
        System.out.println("Product of " + a2 + " and "
                           + b2 + " is:" + ans2); 
    } 
}

输出：

Product of 25 and 36 is:900
Product of 150 and 667 is:100050

范例2：

// Java code to show implementation of 
// checkedMultiply(long a, long b) method 
// of Guava's LongMath class 
  
import java.math.RoundingMode; 
import com.google.common.math.LongMath; 
  
class GFG { 
  
    static long findDiff(long a, long b) 
    { 
        try { 
  
            // Using checkedMultiply(long a, long b) method 
            // of Guava's LongMath class 
            // This should throw "ArithmeticException" 
            // as the product overflows in signed 
            // long arithmetic 
            long ans = LongMath.checkedMultiply(a, b); 
  
            // Return the answer 
            return ans; 
        } 
        catch (Exception e) { 
            System.out.println(e); 
            return -1; 
        } 
    } 
  
    // Driver code 
    public static void main(String args[]) 
    { 
        long a = Long.MIN_VALUE; 
        long b = 452; 
  
        try { 
  
            // Function calling 
            findDiff(a, b); 
        } 
        catch (Exception e) { 
            System.out.println(e); 
        } 
    } 
}

输出：

java.lang.ArithmeticException:overflow

参考：
https://google.github.io/guava/releases/20.0/api/docs/com/google/common/math/LongMath.html#checkedMultiply-long-long-

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注：本文由纯净天空筛选整理自Sahil_Bansall大神的英文原创作品 Java Guava | LongMath.checkedMultiply(int a, int b) method with Examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。