java用户的登录图片_Java--用户登录（JDBC，MYSQL，Servlet）
Java--用户登录（JDBC，MYSQL，Servlet）
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用户登录案例需求
- 编写login.html登录页面
username & password 两个输入框 - 使用Druid数据库连接池技术,操作mysql，day14数据库中user表
- 使用JdbcTemplate技术封装JDBC
- 登录成功跳转到SuccessServlet展示：登录成功！用户名,欢迎您
- 登录失败跳转到FailServlet展示：登录失败，用户名或密码错误
登录页面
Title
创建数据库
CREATE DATABASE login;
USE login;
CREATE TABLE user(
id INT PRIMARY KEY auto_increment,
username VARCHAR(32) UNIQUE NOT NULL,
password VARCHAR(32) NOT NULL
)配置文件
driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql:///login
username=root
password=root
initialSize=5
maxActive=10
maxWait=3000项目依赖
创建用户实体类
创建包cn.guizimo.domain,创建类User
package cn.guizimo.domain;
/**
* @author tanglei
* @date 2020/6/22 10:28 上午
*/
public class User {
private int id;
private String username;
private String password;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + ''' +
", password='" + password + ''' +
'}';
}
}
创建工具类
创建包cn.guizimo.util,编写工具类JDBCUtils
package cn.guizimo.util;
import com.alibaba.druid.pool.DruidDataSourceFactory;
import javax.sql.DataSource;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;
/**
* @author tanglei
* @date 2020/6/22 10:38 上午
*/
public class JDBCUtils {
private static DataSource ds ;
static {
try {
//1.加载配置文件
Properties pro = new Properties();
//使用ClassLoader加载配置文件，获取字节输入流
InputStream is = JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties");
pro.load(is);
//2.初始化连接池对象
ds = DruidDataSourceFactory.createDataSource(pro);
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 获取连接池对象
*/
public static DataSource getDataSource(){
return ds;
}
/**
* 获取连接Connection对象
*/
public static Connection getConnection() throws SQLException {
return ds.getConnection();
}
}
创建数据操作类
创建包cn.guizimo.dao,创建类UserDao,提供login方法
package cn.guizimo.dao;
import cn.guizimo.domain.User;
import cn.guizimo.util.JDBCUtils;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
/**
* @author tanglei
* @date 2020/6/22 10:34 上午
*/
public class UserDao {
private JdbcTemplate template = new JdbcTemplate(JDBCUtils.getDataSource());
public User login(User loginUser) {
try {
String sql = "select * from user where username = ? and password = ?";
User user = template.queryForObject(sql,
new BeanPropertyRowMapper(User.class),
loginUser.getUsername(), loginUser.getPassword());
return user;
} catch (DataAccessException e) {
e.printStackTrace();
return null;
}
}
}
创建servlet类
cn.guizimo.web.servlet.LoginServlet类
package cn.guizimo.web.servlet;
import cn.guizimo.dao.UserDao;
import cn.guizimo.domain.User;
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;
/**
* @author tanglei
* @date 2020/6/22 11:15 上午
*/
@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1.设置编码
req.setCharacterEncoding("utf-8");
//2.获取请求参数
String username = req.getParameter("username");
String password = req.getParameter("password");
//3.封装user对象
User loginUser = new User();
loginUser.setUsername(username);
loginUser.setPassword(password);
//4.调用UserDao的login方法
UserDao dao = new UserDao();
User user = dao.login(loginUser);
//5.判断user
if(user == null){
//登录失败
req.getRequestDispatcher("/failServlet").forward(req,resp);
}else{
//登录成功
//存储数据
req.setAttribute("user",user);
//转发
req.getRequestDispatcher("/successServlet").forward(req,resp);
}
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doGet(req,resp);
}
}
cn.guizimo.web.servlet.FailServlet类
package cn.guizimo.web.servlet;
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;
/**
* @author tanglei
* @date 2020/6/22 11:26 上午
*/
@WebServlet("/failServlet")
public class FailServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//设置编码
resp.setContentType("text/html;charset=utf-8");
//输出
resp.getWriter().write("登录失败，用户名或密码错误");
}
}
cn.guizimo.web.servlet.SuccessServlet类
package cn.guizimo.web.servlet;
import cn.guizimo.domain.User;
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;
/**
* @author tanglei
* @date 2020/6/22 11:31 上午
*/
@WebServlet("/successServlet")
public class SuccessServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//获取request域中共享的user对象
User user = (User) req.getAttribute("user");
if(user != null){
//设置编码
resp.setContentType("text/html;charset=utf-8");
//输出
resp.getWriter().write("登录成功！"+user.getUsername()+",欢迎您");
}
}
}
运行
在浏览器中打开http://localhost:8080/login_test/login.html
登录成功
登录失败
感谢
万能的网络
以及勤劳的自己