Guava – LongMath.checkedAdd方法与实例

CheckedAdd(long a, long b)是Guava的LongMath类的一个方法，它接受两个参数 a 和b ，并返回它们的和。

语法:

public static long checkedAdd(long a, long b)

参数： 该方法接受两个长值a和b并计算它们的总和。

返回值： 该方法返回传递给它的长值的总和，只要它不溢出。

异常情况： 如果总和即(a – b)在有符号长运算中溢出，方法checkedAdd(long a, long b)会抛出ArithmeticException。

下面的例子说明了上述方法的实现。

示例1:

// Java code to show implementation of// checkedAdd(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 checkedAdd(long a, long b)        // method of Guava's LongMath class        long ans1 = LongMath.checkedAdd(a1, b1);          System.out.println("Sum of " + a1 + " and "                           + b1 + " is: " + ans1);          long a2 = 150;        long b2 = 667;          // Using checkedAdd(long a, long b)        // method of Guava's LongMath class        long ans2 = LongMath.checkedAdd(a2, b2);          System.out.println("Sum of " + a2 + " and "                           + b2 + " is: " + ans2);    }}

输出:

Sum of 25 and 36 is: 61Sum of 150 and 667 is: 817

示例2:

// Java code to show implementation of// checkedAdd(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 checkedAdd(long a, long b) method            // of Guava's LongMath class            // This should throw "ArithmeticException"            // as the sum overflows in signed            // long arithmetic            long ans = LongMath.checkedAdd(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:

参考资料：

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