一个简单的分段锁hashmap

public class MyConcurrentHashMap<K,V> {
  private HashMap<K,V> map=new HashMap<K,V>();
  private Object[] locks=null;
  private int lockSize;
  
  
  public MyConcurrentHashMap(int lockSize){
    this.lockSize=lockSize;
    locks=new Object[lockSize];
    for(int i=0;i<lockSize;i++){
      locks[i]=new Object();
    }
  }
  
  private Object getLock(K key){
    return locks[key.hashCode()%lockSize];
  }
  
  public void put(K key,V value){
    synchronized (getLock(key)) {
      this.map.put(key, value);
    }
  }
  
  public V get(K key){
    synchronized (getLock(key)) {
      return this.map.get(key);
    }
  }
}