class tree {
cn conn=new cn();
public void init(javax.servlet.jsp.JspWriter out,javax.servlet.http.HttpServletRequest request) throws Exception {
out.println("<title>用jsp种树</title>");
dowith(request);
buildTree(out,0,0);//初始调用
}
private void dowith(javax.servlet.http.HttpServletRequest request) {
if(request.getParameter("parentid")==null||request.getParameter("parentid").equals(""))return;
String action=request.getParameter("action");
if(action.equals("add"))
conn.executeUpdate("insert into tree(parentid,message) values('"+request.getParameter("parentid")+"','"+request.getParameter("message")+"')");
else if(action.equals("delete"))
conn.executeUpdate("delete from tree where id="+request.getParameter("parentid")+" or parentid="+request.getParameter("parentid"));
}
private boolean has_child(int parentid) throws Exception {
ResultSet rs=conn.executeQuery("select * from tree where parentid="+parentid+" order by id");
return rs.next();
}