Guava – IntMath.checkedMultiply()方法及实例

checkedMultiply(int a, int b)是Guava的IntMath类的一个方法，接受两个参数 a and b ，并退回他们的产品。

语法:

public static int checkedMultiply(int a, int b)

参数: 该方法接受两个int值a和b并计算它们的乘积。

返回值: 该方法返回传递给它的int值的乘积，只要它不溢出。

异常情况: CheckedMultiply(int a, int b)方法在乘积（即(a – b)）溢出的情况下会抛出ArithmeticException。

下面的例子说明了上述方法的实现。

例1:

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

例2:

// Java code to show implementation of
// checkedMultiply(int a, int b) method
// of Guava's IntMath class
  
import java.math.RoundingMode;
import com.google.common.math.IntMath;
  
class GFG {
  
    static int findDiff(int a, int b)
    {
        try {
  
            // Using checkedMultiply(int a, int b) method
            // of Guava's IntMath class
            // This should throw "ArithmeticException"
            // as the product overflows in signed
            // int arithmetic
            int ans = IntMath.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[])
    {
        int a = Integer.MIN_VALUE;
        int b = 452;
  
        try {
  
            // Function calling
            findDiff(a, b);
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}