BinaryTree/BinaryTree.java

public class BinaryTree {
  private Node rootNode = null;
  
  public BinaryTree() {}

  public BinaryTree(int content) {
    insert(content);
  }

  public void insert(int content) {
    if (rootNode == null) {
      Node newNode = new Node(content);
      rootNode = newNode;
    } else {
      insertRecursiv(rootNode, content);      
    }
  }

  private void insertRecursiv(Node currentNode, int content) {
    int currentContent = currentNode.getContent();

    // has to be inserted left
    if (currentContent <= content) {
      // if node == null -> insert left
      if (currentNode.getLeftNode() == null) {
        Node newNode = new Node(content);
        currentNode.setLeftNode(newNode);
        System.out.println("Inserted Left");
        return;
      } else {
        // traverse -> 1 down
        insertRecursiv(currentNode.getLeftNode(), content);
        return;
      }
    } else /* insert right */ {
      // if node == null -> insert right
      if (currentNode.getRightNode() == null) {
        Node newNode = new Node(content);
        currentNode.setRightNode(newNode);
        System.out.println("Inserted Right");
        return;
      } else {
        // traverse -> 1 down
        insertRecursiv(currentNode.getRightNode(), content);
        return;
      }
    }
  }
}