举个例子吧，如下方：
在下面的例子中跑出异常的就是alYN = pru.getAllLM(Integer.parseInt(cnlife_user_userid));这条语句，那么在jsp文件里如何正确的运用ArrayList这个类呢？
jsp.jsp(jsp文件)
<%@ page language="java" contentType="text/html;charset=gb2312"%>
<%@ page import="java.io.*" %>
<%@ page import="java.util.*" %>

<%@ page import="javaclass.javabean.purview.purview" %>
<%!

purview pru = new purview();
ArrayList alYN;
int no;//栏目标识
int YN7 = 0;//删除权限
String QX_a = "";//根据userid,user_lm传出本栏目权限
%>
<%

String dt = request.getParameter("delTag2");

String cnlife_user_userid = (String)session.getAttribute("cnlife_logon_userid");
if(cnlife_user_userid == null || cnlife_user_userid.length()<8){
response.sendRedirect("../../logon.jsp");
}

%>
<%
alYN = pru.getAllLM(Integer.parseInt(cnlife_user_userid));//得到该用户是否是管理员
%>


purview.java(再次我只写其中的一个方法)
public ArrayList getAllLM(int userid)
{
String sql = "select user_lm from rwm where userid = "+userid+"";

ArrayList al = new ArrayList();
purview pru = new purview();
try{
RS= Stmt.executeQuery(sql);
while(RS.next())
{

pru.setLmTag(RS.getInt("user_lm"));
pru.setLmName(pru.getLMname(RS.getInt("user_lm")));
al.add(pru);
}
}catch(SQLException e)
{
System.out.print(e.getMessage());
}
return al;
}