递归算法代码实例

//获取数据方法
    public List<TreeVo> tree(List<ListVo> list, String id, String state,
            String[] str, GetTreeVoInterface getTree) {
        ArrayList<TreeVo> listTree = new ArrayList<TreeVo>();
        //遍历原始数据
        for (int i = list.size(); i > 0; i--) {
            ListVo vo = list.get(i - 1);
            String pid = vo.getPid();
            //清除已处理数据
            if (check(pid, id)) {
                list.remove(vo);
                TreeVo tree = getTree.getTreeVo(vo, str);
                listTree.add(tree);
            }
        }

        // 遍历子节点
        for (TreeVo tree : listTree) {
            //判断是否有数据,没有数据返回上一级
            if (tree.getId() != null) {
                
                String id2 = tree.getId();
                int lastIndexOf = id2.lastIndexOf('/');
                String substring = id2.substring(lastIndexOf+1);
                //运用递归
                //难点在于递归应用的地方以及递归的返回数据
                //如果递归无终止条件,程序将会运行为死循环,无限循环,最终程序会跑死
                List<TreeVo> listTreeChildren = tree(list, substring, state,
                        str, getTree);
                tree.setChildren(listTreeChildren);
            }
        }
        return listTree;
    }