Java通过递归进行二叉树遍历的代码

写代码过程中，将写代码过程重要的代码片段收藏起来，下面的代码是关于Java通过递归进行二叉树遍历的代码，应该是对各朋友有一些好处。

package com.wzs;

public class TestBinaryTree {
	public static void main(String[] args) {
		Node<String> g = new Node<String>("G", null, null);
		Node<String> e = new Node<String>("E", null, null);
		Node<String> f = new Node<String>("F", null, null);
		Node<String> d = new Node<String>("D", null, g);
		Node<String> b = new Node<String>("B", d, e);
		Node<String> c = new Node<String>("C", null, f);
		Node<String> a = new Node<String>("A", b, c);

		System.out.println("生成的二叉树:");
		System.out.println("            A");
		System.out.println("            |     ");
		System.out.println("       |---------|");
		System.out.println("       B         C");
		System.out.println("       |         |");
		System.out.println("  |---------|     -----|");
		System.out.println("  D         E          F");
		System.out.println("  |");
		System.out.println("   ----|");
		System.out.println("       G");

		System.out.println("二叉树深度：" + BinaryTree.getDepth(a));

		System.out.print("前序遍历：");
		BinaryTree.priorderTraversal(a);
		System.out.println();

		System.out.print("中序遍历：");
		BinaryTree.inorderTraversal(a);
		System.out.println();

		System.out.print("后序遍历：");
		BinaryTree.postorderTraversal(a);
		System.out.println();
	}
}

class BinaryTree {
	static <T> void priorderTraversal(Node<T> node) {
		if (node != null) {
			visitNode(node);
			priorderTraversal(node.getLeftChild());
			priorderTraversal(node.getRightChild());
		}
	}

	static <T> void inorderTraversal(Node<T> node) {
		if (node != null) {
			inorderTraversal(node.getLeftChild());
			visitNode(node);
			inorderTraversal(node.getRightChild());
		}
	}

	static <T> void postorderTraversal(Node<T> node) {
		if (node != null) {
			postorderTraversal(node.getLeftChild());
			postorderTraversal(node.getRightChild());
			visitNode(node);
		}
	}

	static <T> int getDepth(Node<T> node) {
		if (node == null) {
			return 0;
		}
		int leftDepth = 0;
		int rightDepth = 0;
		leftDepth = getDepth(node.getLeftChild());
		rightDepth = getDepth(node.getRightChild());
		return (leftDepth > rightDepth ? leftDepth : rightDepth) + 1;
	}

	static <T> void visitNode(Node<T> node) {
		System.out.print(node.getKey() + " ");
	}
}

class Node<T> {
	private T key;
	private Node<T> leftChild;
	private Node<T> rightChild;

	public Node() {

	}

	public Node(T key, Node<T> leftChild, Node<T> rightChild) {
		super();
		this.key = key;
		this.leftChild = leftChild;
		this.rightChild = rightChild;
	}

	public T getKey() {
		return key;
	}

	public void setKey(T key) {
		this.key = key;
	}

	public Node<T> getLeftChild() {
		return leftChild;
	}

	public void setLeftChild(Node<T> leftChild) {
		this.leftChild = leftChild;
	}

	public Node<T> getRightChild() {
		return rightChild;
	}

	public void setRightChild(Node<T> rightChild) {
		this.rightChild = rightChild;
	}

}

                                
                        
                                
输出结果：
                                
                        
                                


生成的二叉树:  
            A  
            |       
       |---------|  
       B         C  
       |         |  
  |---------|     -----|  
  D         E          F  
  |  
   ----|  
       G  
二叉树深度：4  
前序遍历：A B D G E C F   
中序遍历：D G B E A C F   
后序遍历：G D E B F C A