DFS in Java

Main.java

public class Main {

    public static void main(String[] args) {
        Tree tree = initiateTree();

        tree.printTree();

        int searchValue = 10;

        Node resultNode = tree.dfs(searchValue);

        if (resultNode == null) {
            System.out.print("No node found with value " + searchValue);
        } else {
            System.out.print("Found node with value " + searchValue);
        }
    }

    private static Tree initiateTree() {
        Tree tree = new Tree(1);

        tree.addNode(1, 2);
        tree.addNode(1, 3);
        tree.addNode(1, 4);
        tree.addNode(2, 5);
        tree.addNode(2, 6);
        tree.addNode(3, 7);
        tree.addNode(3, 8);

        return tree;
    }

}

Node.java

class Node {

    final int value;

    final List<Node> nodes = new ArrayList<>();

    Node(int value) {
        this.value = value;
    }

    void addChild(Node node) {
        nodes.add(node);
    }
    
}

Tree.java

class Tree {

    private final Node head;

    Tree(int headNodeValue) {
        this.head = new Node(headNodeValue);
    }

    Node dfs(int value) {
        Deque<Node> stack = new LinkedList<>();

        stack.addFirst(head);

        while (!stack.isEmpty()) {
            Node node = stack.removeFirst();

            if (node.value == value) {
                return node;
            }

            for (Node child : node.nodes) {
                stack.addFirst(child);
            }
        }

        return null;
    }

    void addNode(int parentValue, int childValue) {
        Node parentNode = dfs(parentValue);

        if (parentNode != null) {
            parentNode.addChild(new Node(childValue));
        }
    }

    void printTree() {
        Deque<Node> queue = new LinkedList<>();

        queue.addFirst(head);

        while (!queue.isEmpty()) {
            Node node = queue.removeLast();

            for (Node child : node.nodes) {
                queue.addFirst(child);
            }

            System.out.println(node.value);
        }

    }

}