Java中的TreeMap底层源码分析

TreeMap<Integer, String> map = new TreeMap<>();
map.put(2, "张三");
map.put(1, "李四");
map.put(3, "王五");
map.put(4, "赵六");

Map<Integer, String> map = new TreeMap<Integer, String>(new Comparator<Integer> () {
	@Override
	public int compare(Integer o1, Integer o2) {
		return o2 - o1;
	}
}) {};

Entry<K,V> t = root;
if (t == null) {
	compare(key, key); // type (and possibly null) check
	root = new Entry<>(key, value, null);
	size = 1;
	modCount++;
	return null;
}

Comparator<? super K> cpr = comparator;
if (cpr != null) {
	do {
		parent = t;
		cmp = cpr.compare(key, t.key);
		if (cmp < 0)
			t = t.left;
		else if (cmp > 0)
			t = t.right;
		else
			return t.setValue(value);
	} while (t != null);
}
else {
	if (key == null)
		throw new NullPointerException();
	@SuppressWarnings("unchecked")
		Comparable<? super K> k = (Comparable<? super K>) key;
	do {
		parent = t;
		cmp = k.compareTo(t.key);
		if (cmp < 0)
			t = t.left;
		else if (cmp > 0)
			t = t.right;
		else
			return t.setValue(value);
	} while (t != null);
}

if (cmp < 0)
	parent.left = e;
else
	parent.right = e;

fixAfterInsertion(e);

K key;
V value;
Entry<K,V> left;
Entry<K,V> right;
Entry<K,V> parent;
boolean color = BLACK;