Method containsKey

lib/java/util/TreeMap.java:1110–1150

Returns whether this map contains the specified key. @param key the key to search for. @return true if this map contains the specified key, false otherwise. @throws ClassCastException if the specified key cannot be compared with the keys in this

(Object key)

     *             cannot handle {@code null} keys.
     */
    @Override
    public boolean containsKey(Object key) {
        Comparable<K> object = comparator == null ? toComparable((K) key) : null;
        K keyK = (K) key;
        Node<K, V> node = root;
        while (node != null) {
            K[] keys = node.keys;
            int left_idx = node.left_idx;
            int result = cmp(object, keyK, keys[left_idx]);
            if (result < 0) {
                node = node.left;
            } else if (result == 0) {
                return true;
            } else {
                int right_idx = node.right_idx;
                if (left_idx != right_idx) {
                    result = cmp(object, keyK, keys[right_idx]);
                }
                if (result > 0) {
                    node = node.right;
                } else if (result == 0) {
                    return true;
                } else { /*search in node*/
                    int low = left_idx + 1, mid = 0, high = right_idx - 1;
                    while (low <= high) {
                        mid = (low + high) >>> 1;
                        result = cmp(object, keyK, keys[mid]);
                        if (result > 0) {
                            low = mid + 1;
                        } else if (result == 0) {
                            return true;
                        } else {
                            high = mid - 1;
                        }
                    }
                    return false;
                }
            }
        }
        return false;
    }

    /**
     * Returns whether this map contains the specified value.