insomsia的博客

关于HashMap，不论是JDK1.7版本还是1.8版本的分析文章网上多如牛毛，今天咱虽然也是聊HashMap,但是稍微有点不同，是聊它在JDK1.7版本put元素时头插法的实现。不说废话了，直接上源码，先聊JDK1.7的元素插入：public V put(K key, V value) { if (table == EMPTY_TABLE) { inflateTabl...

前面聊了HashMap在JDK1.7版本的头插法实现，现在聊HashMap到了JDK1.8版本升级之后的变化。先上代码：public V put(K key, V value) { return putVal(hash(key), key, value, false, true);}平时java代码都是调的这个方法，实际实现是putVal(hash(key), key, valu...

DDpublic HashMap(int initialCapacity, float loadFactor) { if (initialCapacity < 0) throw new IllegalArgumentException("Illegal initial capacity: " +

public V put(K key, V value) { if (table == EMPTY_TABLE) { inflateTable(threshold); } if (key == null) return putForNullKey(value); int hash = hash(key); int i = in...

public class HashMapTest { Map<String, String>map = new HashMap<String, String>(4); CountDownLatch countDownLatch = new CountDownLatch(2); @Test public void test() throws I...