I have a Ternary Search Tree (Trie) and I want to print out all of the words in it.

How do I go about this using this current implementation that I have below? I have a standard put method to add new words to the tree. I was attempting to print the words using an in-order traversal, but I'm unsure how exactly to complete the function.

class TST {
    private Node root;

    public void put(String key, int value) {
        root = put(root, key, value, 0);
    }

    private Node put(Node node, String key, int value, int index) {
        char c = key.charAt(index);

        if( node == null ){
            node = new Node(c);
        }

        if( c < node.character ){
            node.left = put(node.left, key, value, index);
        }else if( c > node.character ){
            node.right = put(node.right, key, value, index);
        }else if( index < key.length()-1 ){
            node.middle = put(node.middle, key, value, index+1);
        }else{
            node.value = value;
        }

        return node;
    }

    public Integer get(String key) {
        Node node = get(root, key, 0);

        if (node == null) {
            return null;
        }

        return node.value;
    }

    public Node get(Node node, String key, int index) {
        if(node == null) {
            return null;
        }

        char c = key.charAt(index);

        if (c < node.character) {
            return get(node.left, key, index);
        } else if (c > node.character) {
            return get(node.right, key, index);
        } else if(index < key.length() -1) {
            return get(node.middle, key, index);
        } else {
            return node;
        }
    }

    public void inorderTraversal(Node node) {
        System.out.print(node.character + ":" + node.value + " ");

        if(node.left != null) {
            inorderTraversal(node.left);
        }
        if(node.middle != null) {
            inorderTraversal(node.middle);
        }

        if(node.right != null) {
            inorderTraversal(node.right);
        }
    }

    public void traverse() {
        inorderTraversal(root);
    }
}

public class Main {
    public static void main(String[] args) {
        TST tst = new TST();
        tst.put("This",3);
        tst.put("There",4);
        tst.put("Them",5);
        tst.put("High",6);
        System.out.println(tst.get("T"));
        tst.traverse();
    }
}

class Node {
    public char character;
    public Node left, right, middle;
    public int value;

    public Node(char character) {
        this.character = character;
    }
}