Java中的 AtomicReference getAndAccumulate() 方法及示例
AtomicReference类的getAndAccumulate()方法用于使用将给定 accumulatorFunction 应用于当前值和给定值的结果以原子方式更新 AtomicReference 的当前值,并返回前一个值。 accumulatorFunction 应该没有副作用,因为当尝试更新由于线程之间的争用而失败时,它可能会被重新应用。该函数应用当前值作为其第一个参数,并将给定的更新作为第二个参数。
句法:
public final E getAndAccumulate(E x,
BinaryOperator accumulatorFunction)
参数:此方法接受:
- x是更新后的值,并且
- accumulatorFunction是两个参数的无副作用函数。
返回值:该方法返回前一个值。
下面的程序说明了 getAndAccumulate() 方法:
方案一:
Java
// Java program to demonstrate
// AtomicReference.getAndAccumulate() method
import java.util.concurrent.atomic.*;
import java.util.function.BinaryOperator;
public class GFG {
public static void main(String args[])
{
// AtomicReference with value
AtomicReference ref
= new AtomicReference<>(3456);
// Value to apply getAndAccumulate
int x = 45654;
// Declaring the accumulatorFunction
// applying function to add value as string
BinaryOperator add
= (u, v) -> u.toString() + v.toString();
// apply getAndAccumulate()
int value = ref.getAndAccumulate(x, add);
// print AtomicReference
System.out.println(
"The AtomicReference previous value: "
+ value);
System.out.println(
"The AtomicReference new value: "
+ ref.get());
}
}
Java
// Java program to demonstrate
// AtomicReference.getAndAccumulate() method
import java.util.concurrent.atomic.*;
import java.util.function.BinaryOperator;
public class GFG {
public static void main(String args[])
{
// AtomicReference with value
AtomicReference ref
= new AtomicReference("GFG ");
// Value to apply getAndAccumulate
String x = "Welcome";
// Declaring the accumulatorFunction
// applying function to add value as string
BinaryOperator add
= (u, v) -> v + " to " + u;
// apply getAndAccumulate()
String previousValue
= ref.getAndAccumulate(x, add);
// print AtomicReference
System.out.println(
"The AtomicReference previous value: "
+ previousValue);
}
}
输出:
方案二:
Java
// Java program to demonstrate
// AtomicReference.getAndAccumulate() method
import java.util.concurrent.atomic.*;
import java.util.function.BinaryOperator;
public class GFG {
public static void main(String args[])
{
// AtomicReference with value
AtomicReference ref
= new AtomicReference("GFG ");
// Value to apply getAndAccumulate
String x = "Welcome";
// Declaring the accumulatorFunction
// applying function to add value as string
BinaryOperator add
= (u, v) -> v + " to " + u;
// apply getAndAccumulate()
String previousValue
= ref.getAndAccumulate(x, add);
// print AtomicReference
System.out.println(
"The AtomicReference previous value: "
+ previousValue);
}
}
输出:
参考资料: https: Java Java )