/**
  * tree
  */
 @RequestMapping(value = "/tree.do")
 public void mytree(HttpServletResponse response, String id) {
  this.writeJson(response, bookService.getChildrenTree(id));
 }

 @Transactional
 @Override
 public List<Tree> getChildrenTree(String pid) {
  try {
   List<Tree> result = new ArrayList<Tree>();
   //獲得兒子節點的列表
   List<TBookType> childrenList = this.getChildrenType(pid);
   if (childrenList != null && childrenList.size() > 0) {
    for (TBookType child : childrenList) {
     // 獲取孫子的個數
     long count = bookDao.getChildrenCount(String.valueOf(child.getId()));
     Tree node = new Tree();
     node.setId(String.valueOf(child.getId()));
     node.setPid(String.valueOf(child.getPid()));
     node.setText(child.getName());
     node.setChildren(null);
     node.setState(count > 0 ? "closed" : "open");
     //將兒子列表childrenList數據逐個存到樹當中
     result.add(node);
    }
   }
    return result;
  } catch (Exception e) {
   throw new BusinessException("獲取圖書類型數據出現錯誤！", e);
  }
 }

 @Override
 public List<TBookType> getChildrenType(String pid) {
 //這個的pid就是當前展開節點的id , 通過父節點的 id 來獲得子節點
 StringBuilder sqlstr = new StringBuilder();
  if (StringUtils.isBlank(pid))
   sqlstr.append("select * from booktype bt where bt.pid=0");
  else
   sqlstr.append("select * from booktype bt where bt.pid=" + pid );
  return this.search2(TBookType.class, sqlstr.toString());
 }

 @Override
 public long getChildrenCount(String pid) {
 //這個的pid就是當前展開節點的id , 通過父節點的 id 來獲得子節點的個數
  StringBuilder sqlstr = new StringBuilder();
  if (StringUtils.isBlank(pid))
   sqlstr.append("select count(*) from booktype tb where tb.pid='0'");
  else
   sqlstr.append("select count(*) from booktype tb where tb.pid='" + pid + "'");
  return this.count(sqlstr.toString());
 }