使用AtomicInteger原子类代替i++线程安全操作
public class Count {
private static AtomicInteger counter = new AtomicInteger(0);
public static String getCount(){
//线程安全,以原子方式将当前值加1
counter.getAndIncrement();
//线程安全,以原子方式将当前值减1
counter.getAndDecrement();
return counter.toString();
}
}