java基于ConcurrentHashMap设计细粒度实现代码

Map locks = new Map();
 List lockKeys = new List();
for (int number : 1 - 10000) {
	Object lockKey = new Object();
	lockKeys.add(lockKey);
	locks.put(lockKey, new Object());
}
public void doSomeThing(String uid) {
	Object lockKey = lockKeys.get(uid.hash() % lockKeys.size());
	Object lock = locks.get(lockKey);
	synchronized(lock) {
		// do something
	}
}

public class LockPool {
	//用户map
	private static ConcurrentHashMap userMap=new ConcurrentHashMap();
	//用户金额map
	private static ConcurrentHashMap moneyMap=new ConcurrentHashMap();
	public static void main(String[] args) {
		LockPool lockPool=new LockPool();
		ExecutorService service = Executors.newCachedThreadPool();
		service.execute(lockPool.new Boss("u2"));
		service.execute(lockPool.new Boss("u1"));
		service.execute(lockPool.new Boss("u1"));
		service.execute(lockPool.new Boss("u3"));
		service.execute(lockPool.new Boss("u2"));
		service.execute(lockPool.new Boss("u2"));
		service.execute(lockPool.new Boss("u3"));
		service.execute(lockPool.new Boss("u2"));
		service.execute(lockPool.new Boss("u2"));
		service.execute(lockPool.new Boss("u4"));
		service.execute(lockPool.new Boss("u2"));
		service.shutdown();
	}
	class Boss implements Runnable{
		private String userId;
		Boss(String userId){
			this.userId=userId;
		}
		@Override
		    public void run() {
			addMoney(userId);
		}
	}
	public static void addMoney(String userId){
		Object obj=userMap.get(userId);
		if(obj==null){
			obj=new Object();
			userMap.put(userId,obj);
		}
		//obj是与具体某个用户绑定，这里应用了synchronized(obj)的小技巧，而不是同步当前整个对象
		synchronized (obj) {
			try {
				System.out.println("-------sleep4s--------"+userId);
				Thread.sleep(4000);
				System.out.println("-------awake----------"+userId);
			}
			catch (InterruptedException e) {
				e.printStackTrace();
			}
			if(moneyMap.get(userId)==null){
				moneyMap.put(userId,1);
			} else{
				moneyMap.put(userId, moneyMap.get(userId)+1);
			}
			System.out.println(userId+"-------moneny----------"+moneyMap.get(userId));
		}
	}
}

-------sleep4s--------u2
-------sleep4s--------u1
-------sleep4s--------u3
-------sleep4s--------u4
-------awake----------u2
-------awake----------u3
-------awake----------u1
u2-------moneny----------1
u1-------moneny----------1
-------sleep4s--------u1
u3-------moneny----------1
-------sleep4s--------u2
-------sleep4s--------u3
-------awake----------u4
u4-------moneny----------1
-------awake----------u1
u1-------moneny----------2
-------awake----------u3
u3-------moneny----------2
-------awake----------u2
u2-------moneny----------2
-------sleep4s--------u2
-------awake----------u2
u2-------moneny----------3
-------sleep4s--------u2
-------awake----------u2
u2-------moneny----------4
-------sleep4s--------u2
-------awake----------u2
u2-------moneny----------5
-------sleep4s--------u2
-------awake----------u2
u2-------moneny----------6