二、jdk1.8 HashMap底层数据结构图
三、源码
1.散列表（Hash table，也叫哈希表）：
/** * The table, initialized on first use, and resized as * necessary. When allocated, length is always a power of two. * (We also tolerate length zero in some operations to allow * bootstrapping mechanics that are currently not needed.) */ transient Node<K,V>[] table;