Question

我正在尝试将servlet连接到netbeans 8和jdk 8以及glassfish服务器中的mysql数据库。我还在库中包含了mysqlconnector jar文件但是我得到了

Class.forName中未找到类异常（“com.mysql.jdbc.Driver”）

我的代码

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.*;

public class sqltest1 extends HttpServlet {

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        String user = request.getParameter("user");
        String pass = request.getParameter("pass");

            Class.forName("com.mysql.jdbc.Driver");
            Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/demo", "root", "root");
            PreparedStatement pst = conn.prepareStatement("Select user,pass from login where user=? and pass=?");
            pst.setString(1, user);
            pst.setString(2, pass);
            ResultSet rs = pst.executeQuery();
            if (rs.next()) {
                out.println("Correct login credentials");
            } 
            else {
                out.println("Incorrect login credentials");
            }
        } 

        }

Answer 1

尝试将jar文件重新添加到java 构建路径并清理而不是重新编译。

您的代码看起来很好。

Answer 2

检查类路径上的mysql驱动程序jar，并验证正确的mysql驱动程序jar。

Servlet到mysql jdbc连接类未找到异常

2 个答案: