String thirdid=dbo.nextID("7");   // thirdid为11,12,13,14,34,多了一个逗号，下面蓝色的部分是进行处理
 String hqldown="from Source_inf where in ("+thirdid.substring(0,(thirdid.length()-1))+") order by neworders";

DBOperator的一个方法如下
  /**
   * 根据source_type的id判断是下级的id ,现在收录第三级的id
   *
   */
  public String nextID(String id)
  {  
  String myid=id+",";
//  Source_type
//   hql="from Source_type where id="+level;
  String hql="from Source_type where levels="+id;
 // this.setLength(20);
  List secondidL=this.findSQLHibernate(hql, 1);
  Source_type  mytype2=new Source_type();
  Source_type  mytype3=new Source_type();
  for(int q=0;q<secondidL.size();q++)
   {
   mytype2=(Source_type)secondidL.get(q);
  int thisid=mytype2.getId();
  String hql2="from Source_type where levels="+thisid;
  List thirdidL=this.findSQLHibernate(hql2, 1);
   for(int a=0;a<thirdidL.size();a++)
    { mytype3=(Source_type)thirdidL.get(a);
       int thirdid=mytype3.getId();
       myid+=thirdid;
       myid+=",";
    }
   }
 
  return myid;
 
  }