javaWeb登录界面（连接数据库）

用户登录 username: password:

数据库连接代码页面

package com.utils;

import java.io.IOException;import java.io.InputStream;import java.sql.*;import java.util.Properties;

/* * jdbc:javadatabasececonnetion * 链接Mysql数据的工具类 *需要添加mysql的驱动包 * */public class DBUtils { private static String driver;//mysql的驱动类com.mysql.jdbc.Driverprivate static String url;//url：我们要访问的数据库地址private static String username;//username：要连接的数据库的用户名private static String password;//password：要连接的数据库的密码private static Connection conn;//mysql数据库的链接对象

static { try { //通过IO流的输入流（InputStream）读取外部的db.properties文件。InputStream is = DBUtils.class.getClassLoader().getResourceAsStream("db.properties"); Properties properties = new Properties(); properties.load(is); driver = properties.getProperty("driver"); url = properties.getProperty("url"); username = properties.getProperty("username"); password = properties.getProperty("password");

} catch (IOException e) { e.printStackTrace(); } }

public static Connection getConntion() { try { Class.forName(driver); conn = DriverManager.getConnection(url, username, password);

} catch (SQLException | ClassNotFoundException e) { e.printStackTrace(); } return conn; } //自定义方法（release）：释放资源{关闭链接}public static void release(Connection conn, Statement st, ResultSet rs){ try{ if (rs!=null) rs.close(); if (rs!=null) st.close(); if (rs!=null) conn.close();

}catch (SQLException e){

e.printStackTrace(); } } public static void main(String[] args) { System.out.println(getConntion()==null); }}

校验界面

package com.servlet;

import com.entiy.User;import serviceImpl.UserServiceImpl;import servuce.UserService;

import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.util.List;

@WebServlet(urlPatterns = "/UserServlet")//注解的使用public class UserServlet extends HttpServlet { UserService userService = new UserServiceImpl(); @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { this.doPost(req,resp);//重点修改！！！！！}

@Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { //处理jsp的也无需求 /* * 接受 denglu.jsp的用户名和密码 （username和password） * * */String username = req.getParameter("username"); String pwd = req.getParameter("pwd"); /** * 获取数据库中user表中的username和pwd * * * */

List list = userService.userList(); boolean flag = true; int count = 0; for (User u:list){ if (flag){ if (count < list.size()){ if (u.getUname().equals(username)&& u.getUname().equals(pwd)) { req.getRequestDispatcher("main2.jsp").forward(req,resp); break; } count++;

} if (count == list.size()){ req.getRequestDispatcher("error.jsp").forward(req,resp); } } }

}}

数据库地址界面

#资源文件夹#地址driver=com.mysql.jdbc.Driverurl=jdbc:mysql://localhost:3306/yx?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=trueusername=rootpassword=root

失败成功页面省略

package com.entiy;

public class User { private Integer id; private String uname; private String pwd; private String nickname; private Integer age; private String sex; private String sdept; public User() {

}

public User(Integer id, String uname, String psd, String nickname, Integer age, String sex, String sdept) { this.id = id; this.uname = uname; this.pwd = pwd; this.nickname = nickname; this.age = age; this.sex = sex; this.sdept = sdept; }

public void setId(Integer id) { this.id = id; }

public void setUname(String uname) { this.uname = uname; }

public void setPsd(String psd) { this.pwd = pwd; }

public void setNickname(String nickname) { this.nickname = nickname; }

public void setAge(Integer age) { this.age = age; }

public void setSex(String sex) { this.sex = sex; }

public void setSdept(String sdept) { this.sdept = sdept; }

public Integer getId() { return id; }

public String getUname() { return uname; }

public String getPsd() { return pwd; }

public String getNickname() { return nickname; }

public Integer getAge() { return age; }

public String getSex() { return sex; }

public String getSdept() { return sdept; }}

package serviceImpl;

import com.entiy.User;import com.servlet.UserServlet;import dao.IUser;import daoImpl.UserImol;import servuce.UserService;

import java.util.List;

public class UserServiceImpl implements UserService {

IUser userDao = new UserImol(); @Override public List userList() {

return userDao.userList(); }}

package serviceImpl;

import com.entiy.User;import com.servlet.UserServlet;import dao.IUser;import daoImpl.UserImol;import servuce.UserService;

import java.util.List;

public class UserServiceImpl implements UserService {

IUser userDao = new UserImol(); @Override public List userList() {

return userDao.userList(); }}

接口类方法

package dao;

import com.entiy.User;

import java.util.List;

public interface IUser { //验证登录接口List userList();//接口的类表方法

}

package servuce;

import com.entiy.User;

import java.util.List;

public interface UserService { List userList();//接口的类表方法}