Implementation of a Binary Search Tree in Java

Bst.java

package jono.structures;

import java.util.stream.Stream;
import jono.structures.Node;

public class Bst {
  public static void main(String args[]) {
    Node root = null;
    int[] numbers = Stream.of(args[0].split(",")).mapToInt(Integer::parseInt).toArray();

    for(int i = 0; i < numbers.length; i++) {
      int number = numbers[i];

      if (root == null) {
        root = new Node(number);
      } else {
        root.insert(number);
      }
    }

    System.out.println("== IN ORDER ==");
    root.inOrder();
    System.out.println("== PRE ORDER ==");
    root.preOrder();
    System.out.println("== POST ORDER ==");
    root.postOrder();

    System.out.println("Contains 3: " + root.contains(3));
    System.out.println("Contains 1000: " + root.contains(1000));

  }
}

Node.java

package jono.structures;

public class Node {

  Node left, right;
  int value;

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

  public void insert(int value) {
    if (this.value > value) {
      if (this.left == null) {
        this.left = new Node(value);
      } else {
        this.left.insert(value);
      }
    } else {
      if (this.right == null) {
        this.right = new Node(value);
      } else {
        this.right.insert(value);
      }
    }
  }

  public boolean contains(int value) {
    if (this.value == value) { return true; }

    if (this.value > value) {
      if (this.left != null) {
        return this.left.contains(value);
      }
    } else {
      if (this.right != null) {
        return this.right.contains(value);
      }
    }

    return false;
  }

  public void inOrder() {
    if (this.left != null) { this.left.inOrder(); }
    System.out.println(this.value);
    if (this.right != null) { this.right.inOrder(); }
  }

  public void preOrder() {
    System.out.println(this.value);
    if (this.left  != null) { this.left.preOrder();  }
    if (this.right != null) { this.right.preOrder(); }
  }

  public void postOrder() {
    if (this.left  != null) { this.left.preOrder();  }
    if (this.right != null) { this.right.preOrder(); }
    System.out.println(this.value);
  }
}