Tree - Methods

In addition to Set Methods, the class Tree has the following methods.

containsKey This method determines if a key resides in the tree.
getKey This method searches the tree for a given key.
higherKey This method finds an element above a given key.
keyComparator This method gets the key comparator of the tree.
lowerKey This method finds an element below a given key.
readObject This method reads a tree from a stream.
removeKey This method removes the entry with the specified key.
writeObject This method writes a tree to a stream.