用户登录 验证数据库

 login.html

    
    
    



    

            
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JDBCUtils.java

public class JDBCUtils {
    private static DataSource dataSource;
    static {

        try {
            //加载配置文件
            Properties properties = new Properties();
            InputStream resourceAsStream = JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties");
            properties.load(resourceAsStream);
            //初始化连接池对象
//            ds=DruidDataSourceFactory.createDataSource(properties);
            dataSource = DruidDataSourceFactory.createDataSource(properties);
        } catch (IOException e) {

            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public static DataSource getDataSource() {
        return dataSource;
    }

    public static Connection getConnection() throws SQLException{
       return dataSource.getConnection();
    }
}

User.java

public class User {
    private int id;
    private  String username;
    private  String password;
    private String permissions;

    public String getPermissions() {
        return permissions;
    }

    public void setPermissions(String permissions) {
        this.permissions = permissions;
    }

    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 + ''' +
                ", permissions='" + permissions + ''' +
                '}';
    }
}

UserDao.java

public class UserDao {
    private JdbcTemplate jdbcTemplate = new JdbcTemplate(JDBCUtils.getDataSource());

    public User login(User loginUser) {
    //ctrl+alt+t
        try {
            System.out.println(loginUser.getPermissions());
            String sql = "select * from user where username=? and password=? and permissions=?";
            User user = jdbcTemplate.queryForObject(sql,
                    new BeanPropertyRowMapper(User.class), loginUser.getUsername(),loginUser.getPassword(),loginUser.getPermissions());
            return user;
        } catch (DataAccessException e) {
//            e.printStackTrace();
            return null;
        }

    }

}

LoginServlet.java

@WebServlet( "/loginServlet")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request,response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
         //设置编码
        request.setCharacterEncoding("utf-8");
        //获取请求参数
//        String username = request.getParameter("username");
//        String password = request.getParameter("password");
//        //封装user对象
//        User loginUser = new User();
//        loginUser.setUsername(username);
//        loginUser.setPassword(password);

        Map parameterMap = request.getParameterMap();
        //创建User对象
        User loginUser = new User();
        try {
            BeanUtils.populate(loginUser,parameterMap);
            System.out.println(loginUser);
        } catch (IllegalAccessException | InvocationTargetException e) {
            e.printStackTrace();
        }
        //调用UserDao方法
        UserDao userDao = new UserDao();
        User user = userDao.login(loginUser);
        if(user==null)
        {
            request.getRequestDispatcher("/failServlet").forward(request,response);
        }
        else {
            //存储数据
            request.setAttribute("user",user);
            request.getRequestDispatcher("/successServlet").forward(request,response);
        }
    }
}

SuccessServlet.java

@WebServlet("/successServlet")
public class SuccessServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //获取request域中共享的user对象
        User user = (User) request.getAttribute("user");
        if(user!=null) {
            response.setContentType("text/html;charset=utf-8");
            response.getWriter().write("登陆成功"+user.getUsername()+"欢迎您");
        }
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request,response);
    }
}

FailServlet.java

@WebServlet( "/failServlet")
public class FailServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html;charset=utf-8");
        response.getWriter().write("登陆失败，用户名或者密码错误");
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request,response);
    }
}

数据库环境

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