Java Guava | LongMath.checkedMultiply(int a, int b) method with Examples

Last Updated : 31 Jan, 2019

The checkedMultiply(long a, long b) is a method of Guava’s LongMath Class which accepts two parameters a and b, and returns their product.

Syntax:

public static long checkedMultiply(long a, long b)

Parameters: The method accepts two long values a and b and computes their product.

Return Value: The method returns the product of long values passed to it, provided it does not overflow.

Exceptions: The method checkedMultiply(long a, long b) throws ArithmeticException if the product i.e, (a – b) overflows in signed long arithmetic.

Below examples illustrate the implementation of above method:

Example 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); 
    } 
} 

Output:

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

Example 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); 
        } 
    } 
} 