两个文件的相对路径的递归算法

新浪一道面试题：写一个函数，算出两个文件的相对路径的 递归算法

public static void main(String[] args) throws Exception { 

     String pathA = "/a/b/c/d/g/m/1.txt";
     String pathB = "/c/b/c/d/g/h/2.txt";
     System.out.println(pathARelativePathBRecursion(pathA,pathB,""));
 } 

 /**
  * pathA相对于pathB的相对路径 递归算法:
  * 
  * @param pathA
  * @param pathB
  * @param i
  * @return
  */
 public static String pathARelativePathBRecursion(String pathA,String pathB, String tempPath) {
     if (pathA.startsWith(pathB))
         return pathA.replaceFirst(pathB+"/",tempPath.substring(0,tempPath.length()-3));
     else
         return pathARelativePathBRecursion(pathA, pathB.substring(0, pathB.lastIndexOf("/")), "../" + tempPath);
 }