我试图加载或你可以说使用ServletConfig接口注册我的sql jdbc驱动程序 [英] I am trying to load or u can say register my sql jdbc driver with the use of ServletConfig interface
问题描述
我可以通过其他方式加载我的mysql jdbc驱动程序，但是当我尝试使用servletconfig接口注册它时会出现异常
I am able to load my mysql jdbc driver from the other ways but when I am trying to register it with the use of servletconfig interface it gives an exception
java.lang.ClassNotFoundException：drive
java.lang.ClassNotFoundException: drive
虽然我知道servletconfig接口的概念并试图通过遵循这个概念却失败了。
这是我的代码和我用过的其他东西。
Though I know the concept of servletconfig interface and trying to do it by following the concept but failed. Here's my code and other stuff I used.
这里是我的java类
package com.pi.org;
import java.io.IOException;
import javax.sql.*;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class Validation
*/
public class Validation extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public Validation() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
Boolean valid= false;
PrintWriter out = response.getWriter();
String username= request.getParameter("user");
String password= request.getParameter("pass");
try{
ServletConfig config = getServletConfig();
String driver = config.getInitParameter("driver");
Class.forName("driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/newdata","root","annie1993");
PreparedStatement ps= conn.prepareStatement("select * from emp ");
ResultSet rs = ps.executeQuery();
while(rs.next()){
if(username.equals(rs.getString(1))&& password.equals(rs.getString(2)))
{
valid= true;
}
}
if(valid)
{
request.setAttribute("user", username);
RequestDispatcher rd = request.getRequestDispatcher("inbox");
rd.forward(request, response);
}
else{
RequestDispatcher rd = request.getRequestDispatcher("/index");
rd.include(request, response);
out.print("<html><body>either username or password is incorrect<body><html>");
}
}catch(Exception e){e.printStackTrace();}
}
}
推荐答案
错误是因为没有课driver正确的句子是：
The error it's because there is no class "driver" the correct sentence is :
Class.forName("com.mysql.jdbc.Driver");
或
Class.forName( config.getInitParameter("driver") );
但实际上这不是访问servlet中数据库的正确方法，请参阅：的Class.forName（QUOT; com.mysql.jdbc.Driver"）。的newInstance（）
But actually this isn't a correct way to access a database in a servlet see : Class.forName("com.mysql.jdbc.Driver").newInstance()
这篇关于我试图加载或你可以说使用ServletConfig接口注册我的sql jdbc驱动程序的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
