读写锁修饰Map

public class ReadWriteMap<K,V>{
    
    
  private final Map<K,V> map;
  private final ReadWriteLock lock = new ReentrantReadWriteLock();
  private final Lock r = lock.readLock();
  private final Lock w = lock.writeLock();

  public ReadWriteMap(Map<K,V> map){
    
    
    this.map = map;
  }

  public V put(K key,V value){
    
    
    w.lock();
    try{
    
    
      return map.put(key,value);
    }finally{
    
    
      w.unlock();
    }
  }

  public V get(Object key){
    
    
    r.lock();
    try{
    
    
      return map.get(key);
    }finally{
    
    
      r.unlock();
    }
  }
}