Java的LongAccumulator getThenReset() 方法和示例

Java的.LongAccumulator.getThenReset（）是在Java（）一个内置的方法，该方法等效于效果得到（），随后复位。首先，它获取当前值，然后重置该值。

句法：

public long getThenReset()

参数：此方法不接受任何参数。

返回值：此方法返回重置前的值。

下面的程序说明了上述方法：

程序一：

// Program to demonstrate the getThenReset() method
  
import java.lang.*;
import java.util.concurrent.atomic.LongAccumulator;
  
public class GFG {
    public static void main(String args[])
    {
        LongAccumulator num = new LongAccumulator(Long::sum, 0L);
  
        // accumulate operation on num
        num.accumulate(42);
        num.accumulate(10);
  
        num.get();
        // before getThenReset the value is
        System.out.println(" the old value is: " + num);
        ;
  
        // getThenResets current value
        num.getThenReset();
  
        // Print after getThenReset operation
        System.out.println(" the current value is: " + num);
    }
}

输出：

the old value is: 52
 the current value is: 0

方案二：

// Program to demonstrate the getThenReset() method
  
import java.lang.*;
import java.util.concurrent.atomic.LongAccumulator;
  
public class GFG {
    public static void main(String args[])
    {
        LongAccumulator num = new LongAccumulator(Long::sum, 0L);
  
        // accumulate operation on num
        num.accumulate(2);
        num.accumulate(1);
  
        num.get();
        // before getThenReset the value is
        System.out.println(" the old value is: " + num);
          
  
        // getThenResets current value
        num.getThenReset();
  
        // Print after getThenReset operation
        System.out.println(" the current value is: " + num);
    }
}

输出：

the old value is: 3
the current value is: 0

参考：https://docs.oracle.com/javase/8/docs/api/的Java/util/concurrent/atomic/LongAccumulator.html#getThenReset-