Simple implementation of binary serach tree data structure with ints.

BSTree.java

import java.util.Scanner;
public class BSTree {
	private TreeNode root;
	public BSTree() {
		this.root = null;
	}
	public TreeNode getTreeRoot() {
		return this.root;
	}
	public void insert(int val) {
		this.root = insertRecursive(this.root, val);
	}
	public void delete(int val) {
		this.root = deleteRecursive(this.root, val);
	}
	public boolean contains(int key) {
		return containsRecursive(this.root, key);
	}
	private boolean containsRecursive(TreeNode root, int val) {
		if(root == null)
			return false;
		else if(val < root.val)
			return containsRecursive(root.left, val);
		else if(val > root.val)
			return containsRecursive(root.right, val);
		else 
			return true;
	}
	private TreeNode deleteRecursive(TreeNode root, int val) {
		if(root == null)
			return null;
		else if(val < root.val)
			root.left = deleteRecursive(root.left, val);
		else if(val > root.val)
			root.right = deleteRecursive(root.right, val);
		else {
			if(root.left == null) {
				TreeNode temp = root.right;
				root = null;
				return temp;
			}
			else if(root.right == null) {
				TreeNode temp = root.left;
				root = null;
				return temp;
			}
			else {
				int key = minValue(root.right);
				root.val = key;
				deleteRecursive(root.right, key);
			}
		}
		return root;
	}
	private int minValue(TreeNode root) {
		while(root.left != null)
			root = root.left;
		return root.val;
	}
	private TreeNode insertRecursive(TreeNode root, int val) {
		if(root == null)
			root = new TreeNode(val); 
		else if(val < root.val) 
			root.left = insertRecursive(root.left , val);
		else
			root.right = insertRecursive(root.right, val);
		return root;
	}
	public void traverseInorder() {
		inorder(this.root);
	}
	public void traversePreorder() {
		preorder(this.root);
	}
	public void traversePostorder() {
		postorder(this.root);
	}
	private void postorder(TreeNode root) {
		if(root == null)
			return;
		else {
			postorder(root.left);
			postorder(root.right);
			System.out.print(root.val + " ");
		}
	}
	private void preorder(TreeNode root) {
		if(root == null)
			return;
		else {
			System.out.print(root.val + " ");
			preorder(root.left);
			preorder(root.right);
		}
	}
	private void inorder(TreeNode root) {
		if(root == null)
			return;
		else {
			inorder(root.left);
			System.out.print(root.val + " ");
			inorder(root.right);
		}
	}
	private static class TreeNode {
		int val;
		TreeNode left;
		TreeNode right;
		public TreeNode() {
			this.val = 0;
			this.left = this.right = null;
		}
		public TreeNode(int val) {
			this.val = val;
			this.left = this.right = null;
		}
		public boolean isLeaf() {
			if(this.left == null && this.right == null)
				return true;
			return false;
		}
	}
}
class Test {
	public static void main(String[] args) {
		BSTree bsTree = new BSTree();
		int choice;
		Scanner sc = new Scanner(System.in);
		outer:while(true) {
			System.out.println("Enter 1> Insertion 2> Delete 3> Traverse 4> Quit");
			choice = sc.nextInt();
			switch(choice) {
				case 1: System.out.print("Num> ");
						bsTree.insert(sc.nextInt());
						break;
				case 2: System.out.print("Num> ");
						bsTree.delete(sc.nextInt());
						break;
				case 3: bsTree.traverseInorder();
						System.out.println();
						break;
				case 4: break outer;
			}
		}
	}
}
// iterative version
// public void insert(int val) {
	// 	TreeNode cur = this.root;
	// 	if(cur == null) {
	// 		cur = new TreeNode(val);
	// 		this.root = cur;
	// 	}
	// 	else {
	// 		TreeNode prev = cur;
	// 		while(cur != null) {
	// 			prev = cur;
	// 			if(val < cur.val)
	// 				cur = cur.left;
	// 			else
	// 				cur = cur.right;
	// 		}
	// 		if(val < prev.val)
	// 			prev.left = new TreeNode(val);
	// 		else
	// 			prev.right = new TreeNode(val);
	// 	}
		
	// }