Java中的 AtomicLong getAndIncrement() 方法及示例

Java.util.concurrent.atomic.AtomicLong.getAndIncrement()是Java中的一种内置方法，它将给定值加一并返回数据类型为long的更新前的值。

句法：

public final long getAndIncrement()

参数：该函数不接受单个参数。

返回值：函数将执行递增操作前的值返回到上一个值。

下面的程序说明了上述方法：

方案一：

// Java program that demonstrates
// the getAndIncrement() function
  
import java.util.concurrent.atomic.AtomicLong;
  
public class GFG {
    public static void main(String args[])
    {
  
        // Initially value as 0
        AtomicLong val = new AtomicLong(0);
  
        // Decreases and gets
        // the previous value
        long res
            = val.getAndIncrement();
  
        System.out.println("Previous value: "
                           + res);
  
        // Prints the updated value
        System.out.println("Current value: "
                           + val);
    }
}

输出：

Previous value: 0
Current value: 1

方案二：

// Java program that demonstrates
// the getAndIncrement() function
  
import java.util.concurrent.atomic.AtomicLong;
  
public class GFG {
    public static void main(String args[])
    {
  
        // Initially value as 18
        AtomicLong val = new AtomicLong(18);
  
        // Increases 1 and gets
        // the previous value
        long res = val.getAndIncrement();
  
        System.out.println("Previous value: "
                           + res);
  
        // Prints the updated value
        System.out.println("Current value: "
                           + val);
    }
}

输出：

Previous value: 18
Current value: 19

参考： https: Java/util/concurrent/atomic/AtomicLong.html#getAndIncrement–