求一个二叉树的深度以及如何判断一个二叉树是一个平衡二叉树

/** * Created by Administrator on 2015/10/10. */public class TreeNode {    //树节点的值    private char data;    //节点的左子树    private TreeNode leftTree;    //节点的右子树    private TreeNode rightTree;    public TreeNode(char data,TreeNode leftTree,TreeNode rightTree){        this.data=data;        this.leftTree=leftTree;        this.rightTree=rightTree;    }    public int getData() {        return data;    }    public void setData(char data) {        this.data = data;    }    public TreeNode getLeftTree() {        return leftTree;    }    public void setLeftTree(TreeNode leftTree) {        this.leftTree = leftTree;    }    public TreeNode getRightTree() {        return rightTree;    }    public void setRightTree(TreeNode rightTree) {        this.rightTree = rightTree;    }    public static int getDepth(TreeNode pNode){        if(pNode==null){            return -1;        }        TreeNode leftTree=pNode.getLeftTree();        TreeNode rightTree=pNode.getRightTree();        if(leftTree==null||rightTree==null){            return 0;        }        int leftDepth=getDepth(leftTree);        int rightDepth=getDepth(rightTree);        int depth=leftDepth>rightDepth?leftDepth:rightDepth;        return depth+1;    }    //判断二叉树是否为一个平衡二叉树    public static boolean isBalance(TreeNode pNode){        if (pNode==null){            return true;        }        TreeNode leftTree=pNode.getLeftTree();        TreeNode rightTree=pNode.getRightTree();        int leftDepth=getDepth(leftTree);        int rightDepth=getDepth(rightTree);        if(leftDepth-rightDepth>1||rightDepth-leftDepth>1){            return false;        }        if(isBalance(leftTree)){            return isBalance(rightTree);        }else{            return false;        }    }    //测试    public static void main(String[] args){        //TreeNode D=new TreeNode(‘D‘,null,null);        TreeNode E=new TreeNode(‘E‘,null,null);        TreeNode F=new TreeNode(‘F‘,null,null);        TreeNode C=new TreeNode(‘C‘,E,F);        //TreeNode B=new TreeNode(‘B‘,D,null);        TreeNode A=new TreeNode(‘A‘,null,C);        System.out.println(isBalance(A));        //System.out.println(getDepth(A));    }}