用Java构造二叉树

我认为这是您要寻找的：

public class Binarytree{    private static Node root;    public Binarytree(int data)    {        root = new Node(data);    }    public void add(Node parent, Node child, String orientation)    {        if (orientation.equals("left"))        {parent.setLeft(child);        }        else        { parent.setRight(child);        }    }    public static void main(String args[])    {        Node n1 = new Node(1);        Node n2 = new Node(4);        Node n3 = new Node(2);        Node n4 = new Node(5);        Binarytree tree = new Binarytree(3); //  3        tree.add(root, n1, "left"); //         1/         tree.add(root, n2, "right"); // 4        tree.add(n2, n3, "left"); //  2/         tree.add(n2, n4, "right"); //     5    }}class Node {    private int key;    private Node left;    private Node right;    Node (int key) {        this.key = key;        right = null;        left = null;    }    public void setKey(int key) {        this.key = key;    }    public int getKey() {        return key;    }    public void setLeft(Node left) {        this.left = left;    }    public Node getLeft() {        return left;    }    public void setRight(Node right ) {        this.right = right;    }    public Node getRight() {        return right;    }}