java.lang.NumberFormatException，仿BBS小程序出错，进来帮忙看看。。
文件一：
ShowAtricltTree.jsp
<%@ page language="java" contentType="text/html; charset=gbk" pageEncoding="gbk"%><%@ page import="java.sql.*"%><%!String str = ""; private void tree(Connection conn, int id, int level) { Statement stmt = null; ResultSet rs = null; String preStr = ""; for (int i = 0; i < level; i++) { preStr += "----"; } try { stmt = conn.createStatement(); String sql = "select * from article where pid = " + id; rs = stmt.executeQuery(sql); while (rs.next()) { str += "<tr><td>" + rs.getInt("id") + "</td><td>" + preStr+ "<a href='ShowArticleDetail.jsp?ID="+ rs.getInt("id") + "'>" + rs.getString("title") + "</a>" + "</td></tr>"; if (rs.getInt("isleaf") != 0) { tree(conn, rs.getInt("id"), level + 1); } } } catch (SQLException e) { e.printStackTrace(); } finally { try { if (rs != null) { rs.close(); rs = null; } if (stmt != null) { stmt.close(); stmt = null; } } catch (SQLException e) { e.printStackTrace(); } } }%><% Class.forName("com.mysql.jdbc.Driver"); String url = "jdbc:mysql://localhost/bbs?user=root&password=root"; Connection conn = DriverManager.getConnection(url); Statement stmt = conn.createStatement(); ResultSet rs = stmt .executeQuery("select * from article where pid =0"); while (rs.next()) { str += "<tr><td>" + rs.getInt("id") + "</td><td>" + "<a href='ShowArticleDetail.jsp?ID="+rs.getInt("id") + "'>" + rs.getString("title") + "</a>" + "</td></tr>"; if (rs.getInt("isleaf") != 0) { tree(conn, rs.getInt("id"), 1); } } rs.close(); stmt.close(); conn.close();%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=gbk"><title>Insert title here</title></head><body><table border ="1"><%= str %></table></body></html><%@ page language="java" contentType="text/html; charset=GBK" pageEncoding="GBK"%><%@ page import="java.sql.*"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><% String strId = request.getParameter("id"); int id = Integer.parseInt(strId); Class.forName("com.mysql.jdbc.Driver"); String url = "jdbc:mysql://localhost/bbs?user=root&password=root"; Connection conn = DriverManager.getConnection(url); Statement stmt = conn.createStatement(); ResultSet rs = stmt.executeQuery("select * from article where id =" + id);%><html><head><meta http-equiv="Content-Type" content="text/html; charset=GBK"><title>Insert title here</title></head><body><% if(rs.next()) {%><table border="1"> <tr> <td>ID</td> <td><%=rs.getInt("id")%></td> </tr> <tr> <td>Title</td> <td><%=rs.getString("title")%></td> </tr> <tr> <td>Content</td> <td><%=rs.getString("cont")%></td> </tr></table><% } rs.close(); stmt.close(); conn.close();%></body></html>
create database bbs;
use bbs;
create table article
(
id int primary key auto_increment,
pid int,
rootid int,
title varchar(255),
cont text,
pdate datetime,
isleaf int
);
insert into article values (null, 0, 1, '蚂蚁大战大象', '蚂蚁大战大象', now(), 1);
insert into article values (null, 1, 1, '大象被打趴下了', '大象被打趴下了',now(), 1);
insert into article values (null, 2, 1, '蚂蚁也不好过','蚂蚁也不好过', now(), 0);
insert into article values (null, 2, 1, '瞎说', '瞎说', now(), 1);
insert into article values (null, 4, 1, '没有瞎说', '没有瞎说', now(), 0);
insert into article values (null, 1, 1, '怎么可能', '怎么可能', now(), 1);
insert into article values (null, 6, 1, '怎么没有可能', '怎么没有可能', now(), 0);
insert into article values (null, 6, 1, '可能性是很大的', '可能性是很大的', now(), 0);
insert into article values (null, 2, 1, '大象进医院了', '大象进医院了', now(), 1);
insert into article values (null, 9, 1, '护士是蚂蚁', '护士是蚂蚁', now(), 0);