解决方法
Java 8中的变化的本质：
来自您的链接Performance Improvement for HashMap in Java 8
Buckets containing a large number of colliding keys will store their entries in a balanced tree instead of a linked list after certain threshold is reached.
您可以通过改进hashCode实现来减少冲突键的数量来实现等效.
如果没有hashCode计算的详细信息或值的模式,则很难进一步建议.
