问题描述
- 接手别人的JavaEE项目之前运行正确，添加访问数据库后报tomcat异常
-
我重装了tomcat，重新导入了项目又再将我修改的添加进去，运行时报tomcat异常，所以应当不是环境问题报错截图：
访问数据库按照MVC形式，数据显示在getData.jsp中，servlet为GetDServlet.java,
实现从数据库中取数据的类为getD.java,数据表对应的类为inemo_bean,下面贴代码：
package Servlet;
import java.io.IOException;
import java.util.ArrayList;import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
//import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import com.Bean.inemo_bean;
/**
- Servlet implementation class GetDataServlet
*/
@WebServlet("/GetDataServlet")
public class GetDServlet extends HttpServlet {
private static final long serialVersionUID = 1L;/**
- @see HttpServlet#HttpServlet()
*/
public GetDServlet() {
super();
}
/**
- @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
- response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.getWriter().append("Served at: ").append(request.getContextPath());
GetD gd = new GetD();
ArrayList al = gd.getArrayList();
request.setAttribute("al", al);
System.out.println("GetDataServlet.doGet()");
}
/**
- @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
- response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
System.out.println("GetDataServlet.doPost()");
}
- @see HttpServlet#HttpServlet()
}
package Servlet;
import java.sql.SQLException;
import java.util.ArrayList;import com.Bean.inemo_bean;
import com.mysql.jdbc.Connection;
import com.mysql.jdbc.ResultSet;
import com.mysql.jdbc.Statement;
import com.scut.older.db.DB;/**
- Servlet implementation class getData
- */
public class GetD {private Statement st = null;
private ResultSet rs = null;
private Connection ct = null;public ArrayList getArrayList() {
ArrayList<inemo_bean> al = new ArrayList<inemo_bean>(); String sql = "select * from sensor_data_inemo"; ct = (Connection) new DB().getConn(); st = (Statement) new DB().getStatement(ct); rs = (ResultSet) new DB().getResultSet(st, sql); try { while (rs.next()) { inemo_bean ib = new inemo_bean(); ib.setId_sensor_data_iNEMO(rs.getInt("id_sensor_data_iNEMO")); ib.setDatetime(rs.getInt("datetime")); ib.setAccx(rs.getInt("accx")); ib.setAccy(rs.getInt("accy")); ib.setAccz(rs.getInt("accz")); ib.setGyrox(rs.getInt("gyrox")); ib.setGyroy(rs.getInt("gyroy")); ib.setGyroz(rs.getInt("gyroz")); ib.setMagx(rs.getInt("magx")); ib.setMagy(rs.getInt("magy")); ib.setMagz(rs.getInt("magz")); ib.setPress(rs.getInt("press")); ib.setTemp(rs.getInt("press")); ib.setAltitude(rs.getInt("altitude")); ib.setLongitude(rs.getInt("longitude")); ib.setLatitude(rs.getInt("latitude")); al.add(ib); } } catch (SQLException e) { e.printStackTrace(); System.out.println("getData.getArrayList()"); System.err.println("getdata()出错"); } finally { closeSource(); } return al;}
private void closeSource() {
try {
if (rs != null)
rs.close();
if (st != null)
st.close();
if (ct != null)
ct.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}public GetD() {
super();
}
}
<%@page import="com.Bean.inemo_bean"%>
<%@page import="java.util.ArrayList"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">Data from inemo
Get Data From DataBase -sensor_inemo_data
<%
ArrayList al = (ArrayList)request.getAttribute("al");
%>
id_sensor_data_iNEMO datetime accx accy accz gyrox gyroy gyroz magx magy magz press temp altitude longitude latitude <%
for (int i = 1; i <= al.size(); i++) {
inemo_bean inemo = al.get(i);
%>
<%=inemo.getId_sensor_data_iNEMO()%> <%=inemo.getDatetime()%> <%=inemo.getAccx()%> <%=inemo.getAccy()%> <%=inemo.getAccz()%> <%=inemo.getGyrox()%> <%=inemo.getGyroy()%> <%=inemo.getGyroz()%> <%=inemo.getMagx()%> <%=inemo.getMagy()%> <%=inemo.getMagz()%> <%=inemo.getPress()%> <%=inemo.getTemp()%> <%=inemo.getAltitude()%> <%=inemo.getLongitude()%> <%=inemo.getLatitude()%> </tr> <% } %> </table> - Servlet implementation class GetDataServlet
解决方案
谢谢大家我自己找到bug了，我的两个servlet在配置文件中写重复了
解决方案二：
自己打个断点，F6单步执行。找到报错的地方
解决方案三：
是不是tomcat中配置jndi时没配置正确
解决方案四：
tomcat里面的catalina里面清除下。
解决方案五：
仔细看看配置有没有错误！！
解决方案六：
谢谢大家我自己找到bug了，我的两个servlet在配置文件中写重复了