二叉树遍历 前序 中序 后序

package com.pay.test;

import java.util.LinkedList;

public class Node {

    private Integer data;
    private  Node left;
    private  Node right;

    public Integer getData() {
        return data;
    }

    public void setData(Integer data) {
        this.data = data;
    }

    public Node getLeft() {
        return left;
    }

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

    public Node getRight() {
        return right;
    }

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

    public Node(Integer data) {
        this.data = data;
    }
    public static  Node createNode(LinkedList<Integer> list){
        if(list==null || list.isEmpty()){

            return null;
        }
       Integer data= list.removeFirst();
        Node node;
        if(data!=null ){
            node=new Node(data);

        }
        return null;
    }

    //前序遍历
    public void preOrderPrint(Node root){
        if(root==null){
            return;
        }else {
        System.out.println(root.data+"");
            preOrderPrint(root.left);
            preOrderPrint(root.right);
        }
    }
    //中序遍历
    public void inOrderPrint(Node node){
        if(node==null){
            return;
        }else {
            inOrderPrint(node.left);
            System.out.println(node.data);
            inOrderPrint(node.right);
        }
    }
    //后续遍历
    public void postOrderPrint(Node node){
        if(node==null){
            return;
        }else {
            postOrderPrint(node.left);
            postOrderPrint(node.right);
            System.out.println(node.data);
        }

    }

}

　　测试类

package com.pay.test;

public class Test {

    public static void main(String[] args) {

    Node root=new Node(1);
        Node left=new Node(22);
        Node left1=new Node(44);
        Node left2=new Node(44);

        Node right=new Node(55);
        Node right1=new Node(6);
        Node right2=new Node(7);
        left1.setLeft(left2);
        left.setLeft(left1);
        root.setLeft(left);

        right1.setRight(right2);
        right.setRight(right1);
        root.setRight(right);

        System.out.println("前序遍历");
        root.preOrderPrint(root);

        System.out.println("中序遍历");
        root.inOrderPrint(root);

        System.out.println("后序遍历");
        root.postOrderPrint(root);


    }
}