public static void main(String[] args) { User user = new User("张三", 20); atomicReference.set(user); User updateUser = new User("李四",25); atomicReference.compareAndSet(user,updateUser); System.out.println(atomicReference.get()); } static class User{ private String name; private int...
//AtomicIntegerFieldUpdater 是一个抽象类,具体是由子类 AtomicIntegerFieldUpdaterImpl 实现的 public static <U> AtomicIntegerFieldUpdater<U> newUpdater(Class<U> tclass, String fieldName) { return new AtomicIntegerFieldUpdaterImpl<U> (tclass, fieldName, Reflection.getCallerClass()); } AtomicIntegerFieldUpdater...
importjava.util.concurrent.ConcurrentHashMap;importjava.util.concurrent.atomic.AtomicInteger;publicclassConcurrentHashMapWithAtomicDemo{privatefinal ConcurrentHashMap<String,AtomicInteger>concurrentHashMap=newConcurrentHashMap<>();publicvoidincrement(String key){AtomicInteger value=concurrentHashMap.get(key);if(val...
Uses of AtomicLongFieldUpdater in java.util.concurrent.atomic Methods in java.util.concurrent.atomic that return AtomicLongFieldUpdater Modifier and Type Method Description static <U> AtomicLongFieldUpdater<U> AtomicLongFieldUpdater.newUpdater(Class<U> tclass, String fieldName) Creates and return...
public class AtomicIntegerArrayDemo { static AtomicIntegerArray arr = new AtomicIntegerArray(10); public static void main(String[] args) throws InterruptedException { Thread[] ts = new Thread[10]; for (int k = 0; k < 10; k++) { ts[k] = new Thread(new AddThread()); ...
}publicstaticvoidmain(String[] args) { Entity entity =newEntity(); Unsafe unsafe =UnsafeFactory.getUnsafe();long offset = UnsafeFactory.getFieldOffset(unsafe, Entity.class, "x");booleansuccessful;//4个参数分别是:对象实例、字段的内存偏移量、字段期望值、字段更新值,返回值为布尔值,成功为true,失...
一、Java原子操作类概述 1、什么是原子操作类 Java从JDK1.5开始提供了java.util.concurrent.atomic包,这个包中的原子操作类提供了一种用法简单,性能高效,线程安全地更新一个变量的方式。 2、为什么要用原子操作类 《阿里巴巴Java开发手册中》: 【参考】 volatile 解决多线程内存不可见问题。对于一写多读,是可以解决...
import java.util.concurrent.atomic.AtomicInteger; public class AtomicIntegerTest { public static void main(String[] args) { int temvalue = 0; AtomicInteger i = new AtomicInteger(0); temvalue = i.getAndSet(3); System.out.println("temvalue:" + temvalue + "; i:" + i); //temvalue:0...
使用10个线程, 同时尝试修改AtomicReference中的String, 最终只有一个线程可以成功。 importjava.util.concurrent.atomic.AtomicReference;publicclassAtomicReferenceTest{publicfinalstaticAtomicReference<String> attxnicStr =newAtomicReference<String>("abc");publicstaticvoidmain(String[] args){for(inti=0; i <10; i...
import java.util.concurrent.atomic.LongAdder;public class HighConcurrencyCounter {private LongAdder counter = new LongAdder();public void increment() {counter.increment();}public long getCount() {return counter.sum();}public static void main(String[] args) {HighConcurrencyCounter highConcurrencyCoun...