代码

import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicIntegerArray;
import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.IntUnaryOperator;

public class Sequence {

    private AtomicInteger value = new AtomicInteger();
    private int s[]={2,1,4,5,6};
    AtomicIntegerArray a = new AtomicIntegerArray(s);
    AtomicReference<User> user = new AtomicReference<User>();
    AtomicIntegerFieldUpdater<User> old = AtomicIntegerFieldUpdater.newUpdater(User.class, "old");
    /*
     *  public final int getAndUpdate(IntUnaryOperator updateFunction) {
        int prev, next;
        do {
            prev = get();
            next = updateFunction.applyAsInt(prev);
        } while (!compareAndSet(prev, next));
        return prev;
    }底层采用cas操作，获取当前值和预期的下个值，cas比较，为真则返回
     * 
     */
    public int getNext(){
        return value.getAndIncrement();             
    }
    
    public void getArrayNexy(){
        
        old.getAndIncrement(new User());
//      数组第二个位置的元素加10
        a.addAndGet(1, 10);
        a.getAndIncrement(1);
    }
    
    public static void main(String[] args) {
        Sequence s = new Sequence();
        
        
        new Thread(new Runnable() {
            
            @Override
            public void run() {
                // TODO Auto-generated method stub
                while (true) {
                    System.out.println(Thread.currentThread().getName() + " "+s.getNext());
                    try {
                        Thread.sleep(100);
                    } catch (Exception e) {
                        // TODO: handle exception
                    }
                }
            }
        }).start();
        
        new Thread(new Runnable() { 
            @Override
            public void run() {
                // TODO Auto-generated method stub
                while (true) {
                    System.out.println(Thread.currentThread().getName() + " "+s.getNext());
                    try {
                        Thread.sleep(100);
                    } catch (Exception e) {
                        // TODO: handle exception
                    }
                }
            }
        }).start();
        
    }
}