HashObject之LinkedBaseHashObject

/**
* 该类主要在BaseHashObject类基础上，增加了双向链表的支持。
*
*/
public abstract class LinkedBaseHashObject extends BaseHashObject{
LinkedBaseHashObject before, after;
    @SuppressWarnings("unchecked")
public void recordAccess(HashObjectMap<? extends BaseHashObject> m){
    LinkedHashObjectMap<LinkedBaseHashObject> lm = (LinkedHashObjectMap<LinkedBaseHashObject>)m;
        if (lm.isAccessOrder()) {
            lm.modCount++;
            remove();
            addBefore(lm.getHeader());
        }
}
public void recordRemoval(HashObjectMap<? extends BaseHashObject> m){
remove();
}
public void remove() {
        before.after = after;
        after.before = before;
    }
public void addBefore(LinkedBaseHashObject existingObject) {
        after  = existingObject;
        before = existingObject.before;
        before.after = this;
        after.before = this;
    }
}