Java开发网 - 各位大虾帮帮忙

Topic: 各位大虾帮帮忙

1.各位大虾帮帮忙

Posted by: J2EE1982
Posted on: 2005-08-18 17:57

<%@ page language = "java" contentType = "text/html;charset=gb2312" errorPage="error.jsp"%>
<%@ page import = "java.sql.*" %>
<%@ page import = "com.Mysql" %>
<%

  Mysql mysql = new Mysql();
  int intPage;
  int currentPage = 1;
  int PageNumbers = 10;
  if(request.getParameter("page")!=null && request.getParameter("page")!="")
    intPage = Integer.parseInt(request.getParameter("page"));
  else
    intPage = 1;
  int totalRecord = 0;
  ResultSet counters = mysql.executeQuery("select count Start

as cnt from stsNews");
  if(counters.next())
  {
    totalRecord = counters.getInt("cnt");
  }
%>
<html>
<head><title>新闻发布系统1.0版</title>
<LINK href="css/sts.css" rel=stylesheet type=text/css>
</head>
<body>
<div align="center" style="width: 901; height: 21">
<%@ include file="inc/top.jsp" %>
<br>
<table border = 0 width="505" cellspacing="0" cellpadding="2" style="border-collapse: collapse" bordercolor="#111111">
<tr bgcolor="#00ff00"><td width="505" colspan=2><img src="pic\qq.gif">新闻标题</td></tr>
<%
  if(session.getValue("name")==null || session.getValue("name")=="")
  {
    %>
<%

  String strSQL = "select id,title from stsNews order by id desc";
  ResultSet rs = mysql.executeQuery(strSQL);
  int i=0;
  while(rs.next())
  {

    if(i >= (intPage-1)*PageNumbers && i < intPage*PageNumbers)
    {
      String id = rs.getString("id");
      String title = rs.getString("title");
      out.print("<tr bgcolor = \"#00dc45\"><td width=300 valign=\"top\"><img src=\"pic\\gb.gif\"><a href=\"view.jsp?id="+id+"\">"+ title +"</a></td><td></td></tr>");
    }
    i++;
  }
%>
</table>
</div>
<%

rs.close();
}
else
{
%>
<%
  String strSQL = "select id,title from stsNews order by id desc";
  ResultSet rs = mysql.executeQuery(strSQL);
  int i=0;
  while(rs.next())
  {

    if(i >= (intPage-1)*PageNumbers && i < intPage*PageNumbers)
    {
      String id = rs.getString("id");
      String title = rs.getString("title");
      out.print("<tr bgcolor = \"#00dc45\"><td valign=\"top\" width=\"90%\"><img src=\"pic\\gb.gif\"><a href=\"view.jsp?id="+id+"\">"+ title +"</a></td><td width=\"10%\"><a href=\"delete.jsp?id="+id+"\">删除</a></td></tr>");
    }
    i++;
  }
%>
</table>

<%
rs.close();
  }
%>
<br>
<div align="center" >新闻总数：<%= totalRecord %> 当前页数：<%=currentPage%> 每页显示<%=PageNumbers%>条共<%=(totalRecord+PageNumbers)/PageNumbers%>页 <a href="index.jsp?page=1">首页</a>

<%
  if(intPage>1 && intPage<((totalRecord+PageNumbers)/PageNumbers))
  {
    out.print("<a href='index.jsp?page=" + (intPage-1) + "'>上一页  </a>");
    out.print("<a href='index.jsp?page=" + (intPage+1) +"'>下一页  </a>");
    out.print("<a href='index.jsp?page=" + ((totalRecord+PageNumbers)/PageNumbers) + "'>最后一页</a>");
  }
  if(intPage ==((totalRecord+PageNumbers)/PageNumbers))
    out.print("<a href='index.jsp?page=" + (intPage-1) + "'>上一页  </a>");
  if(intPage == 1)
  {
    out.print("<a href='index.jsp?page=" + (intPage+1) +"'>下一页  </a>");
    out.print("<a href='index.jsp?page=" + ((totalRecord+PageNumbers)/PageNumbers) + "'>最后一页</a>");
  }
%>
</div>
<%
  counters.close();
%>
<div align="center"><a href="manager.jsp" >进入管理</a> <a href="manager.jsp">发布文章</a> <a href="admin.jsp">登录</a><br>
<%@ include file="inc/bottom.jsp" %></div>
</body>
</html>

一个新闻发布系统的主页面,Mysql.java是相关的 mysql jdbc操作.

运行出错:

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException
  org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:372)
  org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
  org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

root cause

java.lang.NullPointerException
  org.apache.jsp.index_jsp._jspService(index_jsp.java:72)
  org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
  org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
  org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
  org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

note The full stack trace of the root cause is available in the Apache Tomcat/5.0.28 logs.

2.Re:各位大虾帮帮忙 [Re: J2EE1982]	Copy to clipboard
Posted by: chengbd Posted on: 2005-08-19 02:17 不知您的Mysql 是如何定义的？既然是“java.lang.NullPointerException”，建议你单步执行，或是一句句的通过输出调试信息来判断是哪个对象为null吧。对你这样简单的问问题，却不多做介绍，觉得不妥，少了些诚意。

3.Re:各位大虾帮帮忙 [Re: J2EE1982]	Copy to clipboard
Posted by: chengbd Posted on: 2005-08-19 02:24 http://www.cjsdn.net/post/view?bid=51&id=153300 重复发帖，扣分，希望您能在希望获取的同时先付出些精力！