用java写的一个简单二叉树的插入和中序遍历

树的节点bean

public class TreeNode {
	
	//节点的内容
	private NodeBean  data ;
	//左节点
	private TreeNode left;
	//右节点
	private TreeNode rigth;
	
	//构造函数
	public TreeNode(){
		data = new NodeBean();
	}
}

二叉树类

public class Tree {
	private TreeNode root;
	
	Tree(){
		root = new TreeNode();
		NodeBean nodeBean = new NodeBean();
		nodeBean.setKey(60);
		root.setData(nodeBean);
	}
	
	public NodeBean find(int key){
		return null;
	}
	
	//给树插入数据	
	public void insert(TreeNode root,TreeNode bean) {
		if (root == null) {
			root = bean;
		} else {
			if (bean.getData().getKey() < root.getData().getKey()) {
				if (root.getLeft() == null) {
					root.setLeft(bean);
				} else{
					insert(root.getLeft(),bean);
				}
			} else {
				if (root.getRigth() == null) {
					root.setRigth(bean);
				} else{
					insert(root.getRigth(),bean);
				}
			}
		}
	}
	
	//中序遍历二叉树
	public  String  middleIterator(TreeNode tree){
		StringBuilder sb = new StringBuilder();
		
		if (tree == null) {
			return sb.toString();
		} else{
			sb.append(tree.getData().getKey()+",");
			
			sb.append(middleIterator(tree.getLeft()));
			
			sb.append(middleIterator(tree.getRigth()));
		}
		
		return sb.toString();
	}
	
	
	public static void main(String[] args) {
		Tree myTree = new Tree();
		TreeNode treeNode = new TreeNode();
		treeNode.getData().setKey(50);
		
		TreeNode treeNode1 = new TreeNode();
		treeNode1.getData().setKey(45);
		
		TreeNode treeNode2 = new TreeNode();
		treeNode2.getData().setKey(30);
		
		TreeNode treeNode3 = new TreeNode();
		treeNode3.getData().setKey(55);
		
		TreeNode treeNode4 = new TreeNode();
		treeNode4.getData().setKey(70);
		
		myTree.insert(myTree.root, treeNode);
		myTree.insert(myTree.root, treeNode1);
		myTree.insert(myTree.root, treeNode2);
		myTree.insert(myTree.root, treeNode3);
		myTree.insert(myTree.root, treeNode4);
		
		String result = myTree.middleIterator(myTree.getRoot());
		System.out.println(result);
	}