二叉树最近公共父节点

有一个普通二叉树，AB分别为两个子节点，求AB最近的公共父节点。

import java.util.ArrayList;
import java.util.List;


public class Node {

    Node leftChild;
    Node rightChild;
    int data;
    
    public Node(Node leftChild,Node rightChild,int data){
        this.leftChild = leftChild;
        this.rightChild = rightChild;
        this.data = data;
    }
    
    public boolean getPath(Node root,Node decNode,List<Node> array){
        boolean findResult = false;
        if(null != root){
            if(root == decNode){
                array.add(root);
                findResult = true;
            }
            if(!findResult&& root.leftChild!=null){
                findResult = this.getPath(root.leftChild, decNode, array);
                if(findResult){
                    array.add(root);
                }
            }
            if(!findResult&& root.rightChild!=null){
                findResult = this.getPath(root.rightChild, decNode, array);
                if(findResult){
                    array.add(root);
                }
            }
        }
        return findResult;
    }
    
    static Node getCommonRoot(Node root,Node a,Node b){
        Node common = null;
        List<Node> pathA = new ArrayList<Node>();
        List<Node> pahtB = new ArrayList<Node>();
        a.getPath(root, a, pathA);
        b.getPath(root, b, pahtB);
        for(Node NodeA:pathA){
            for(Node NodeB:pahtB){
                if(NodeA == NodeB){
                    common = NodeA;
                    break;
                }
            }
            if(null!=common){
                break;
            }
        }
        return common;
    }
    
    /**
     * @param args
     */
    public static void main(String[] args) {
        
        Node g = new Node(null,null,7);
        Node f = new Node(null,null,6);
        Node e = new Node(null,null,5);
        Node d = new Node(null,null,4);
        Node c = new Node(f,g,3);
        Node b = new Node(d,e,2);
        Node a = new Node(b,c,1); 
        
        Node test=null;
        test = getCommonRoot(a,b,f);
        if(null!=test){
            System.out.println(test.data);
        }
    }

}