本文出自：http://blog.csdn.net/svitter

资源下载：

github:

git clone https://github.com/Svtter/JSP-tomcat-mysql

使用了servlet:

web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">
  <display-name>JSP_servlet_javabean</display-name>
	<servlet>
		<description>配置用於用戶登錄的Servlet</description>
		<display-name>LoginServlet</display-name>
		<servlet-name>LoginServlet</servlet-name>
		<servlet-class>LoginServlet</servlet-class>
	</servlet>  
	<servlet-mapping>
		<servlet-name>LoginServlet</servlet-name>
		<url-pattern>/LoginServlet</url-pattern>
	</servlet-mapping>
	<welcome-file-list>
    	<welcome-file>login.html</welcome-file>
  	</welcome-file-list>
</web-app>

LoginServlet.java://用于验证：

import java.io.*;

import javax.servlet.*;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import bean.ConnectionBean;
import bean.userBean;

/**
 * @author Svitter
 *
 */
@SuppressWarnings("serial")
public class  LoginServlet extends HttpServlet {
	userBean user =  new userBean();
	ConnectionBean connBean = new ConnectionBean();
	public void doPost(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
		String checkLogin;
		String username = request.getParameter("login");
		String password = request.getParameter("password");
		checkLogin = connBean.checkUser(username, password);
		if(checkLogin.equals("Success")) {
			user.setUserName(username);
			request.setAttribute("user", user);
			getServletConfig().getServletContext().getRequestDispatcher("/loginsuccess.jsp").forward(request, response);
		} else {
			request.setAttribute("checkLogin", checkLogin);
			getServletConfig().getServletContext().getRequestDispatcher("/loginCheck.jsp").forward(request, response);
		}
	}
	public void doGet(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException{
		String username = request.getParameter("login");
		String password = request.getParameter("password");
		connBean.addUser(username, password);
		getServletConfig().getServletContext().getRequestDispatcher("/login.html").forward(request, response);
	}
}

package bean;
import java.io.*;
import java.util.Properties;
import java.sql.*;
public class GetConnection {
	private static Properties p;
	static{
		try{
			p = new Properties();
			InputStream is = GetConnection.class.getResourceAsStream("property.conf");
			p.load(is);
			is.close();
		} catch(Exception e) {
			e.printStackTrace();
		}
	}
	public static String getProperty(String key){
		return p.getProperty(key);
	}
	static String driver = GetConnection.getProperty("driver");
	static String url = GetConnection.getProperty("url");
	static  String name = GetConnection.getProperty("user");
	static String pass = GetConnection.getProperty("password");
	static{
		try{
			Class.forName(driver);
		}catch(ClassNotFoundException e){
			e.printStackTrace();
		}
	}
	public static Connection getConnection() throws SQLException {
		return DriverManager.getConnection(url, name, pass);
	}
}

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/users
user=root
password=root

package bean;

import java.sql.*;

public class ConnectionBean {
	private Connection con;
	public ConnectionBean() {
		try{
			con = GetConnection.getConnection();
		} catch (Exception e){
			e.printStackTrace();
		}
	}
	//向数据库添加信息
	public boolean addUser(String name, String password){
		try{
			PreparedStatement pstmt = con.prepareStatement("insert into ur(name, passwd) values(?,?)");
			pstmt.setString(1, name);
			pstmt.setString(2, password);
			pstmt.execute();
			return true;
		} catch (Exception e){
			e.printStackTrace();
			return false;
		}
	}
	public ResultSet getUser(String name){
		try {
			Statement stm = con.createStatement();
			ResultSet result = stm.executeQuery("select * from ur where name='"+name+"'");
			return result;
		} catch (Exception e){
			e.printStackTrace();
			return null;
		}
	}
	public String checkUser(String name, String passwd){
		String checkUser=null;
		try{
			Statement stm = con.createStatement();
			ResultSet result = stm.executeQuery("select * from ur where name='"+name+"'");
			if(result.next()==false){
				checkUser = "No user";
			}
			else{
				if(result.getString("passwd").equals(passwd)){
					checkUser = "Success";
				}
				else{
					checkUser = "Wrong passwd";
				}
			}
		}catch (Exception e){
			e.printStackTrace();
		}
		return checkUser;
	}
}