Binary Tree Traversal

 public class TreeNode {

    Integer value;
    TreeNode left;
    TreeNode right;

    public TreeNode(Integer value) {
        this.value = value;
    }

    public Integer getValue() {
        return value;
    }

    public void setValue(Integer value) {
        this.value = value;
    }

    public TreeNode getLeft() {
        return left;
    }

    public void setLeft(TreeNode left) {
        this.left = left;
    }

    public TreeNode getRight() {
        return right;
    }

    public void setRight(TreeNode right) {
        this.right = right;
    }
}

public class TreeTraversal {

    public static TreeNode createTree()
    {
        TreeNode rootNode = new TreeNode(9);
        TreeNode node1 = new TreeNode(7);
        TreeNode node2 = new TreeNode(10);
        TreeNode node3 = new TreeNode(3);
        TreeNode node4 = new TreeNode(8);

        rootNode.setLeft(node1);
        rootNode.setRight(node2);
        node1.setLeft(node3);
        node1.setRight(node4);


        return rootNode;
    }

    public static void preOrder(TreeNode rootNode)
    {
        if(rootNode==null) return;
        System.out.println("Value-->"+rootNode.getValue());
        preOrder(rootNode.left);
        preOrder(rootNode.right);

    }

    public static void postOrder(TreeNode rootNode)
    {
        if(rootNode==null) return;
        postOrder(rootNode.left);
        postOrder(rootNode.right);
        System.out.println("Value-->"+rootNode.getValue());
    }

    public static void inOrder(TreeNode rootNode)
    {
        if(rootNode==null) return;
        inOrder(rootNode.left);
        System.out.println("Value-->"+rootNode.getValue());
        inOrder(rootNode.right);
    }

    public static void main(String args[])
    {
       TreeNode rootNode =  createTree();

       System.out.println("PRE ORDER");
       preOrder(rootNode);
       System.out.println("POST ORDER");
       postOrder(rootNode);
       System.out.println("IN ORDER");
       inOrder(rootNode);
       System.out.println("Find Even Numbers");
       findEvenNumbers(rootNode);
    }

    public static void findEvenNumbers(TreeNode node)
    {
        if(node==null) return;
        if(node.getValue()%2==0) System.out.println(node.getValue());
        findEvenNumbers(node.left);
        findEvenNumbers(node.right);
    }
}

Output
PRE ORDER
Value-->9
Value-->7
Value-->3
Value-->8
Value-->10
POST ORDER
Value-->3
Value-->8
Value-->7
Value-->10
Value-->9
IN ORDER
Value-->3
Value-->7
Value-->8
Value-->9
Value-->10
Find Even Numbers
8
10