Web登录验证功能

封装用户对象

package itcast.domain;
public class User {
    private int id;
    private String username;
    private String password;
    private String gender;
    
    public void setHehe(String gender){
        this.gender=gender;
    }
    public String getHehe(){
       return gender;
    }
    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 + '\'' +
                ", gender='" + gender + '\'' +
                '}';
    }
}

连接数据库进行查询

package itcast.dao;
import itcast.domain.User;
import itcast.util.JDBCUtils;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
public class UserDao {
    //声明JDBCTemplate对象公用
    private JdbcTemplate template=new JdbcTemplate(JDBCUtils.getDataSource());
    //登录方法
    public User login(User loginUser){
        try {
            //1.编写sql
            String sql="select *from user where username=?and password=?";
            //2.调用query方法
            User user=template.queryForObject(sql,
                    new BeanPropertyRowMapper<User>(User.class),
                    loginUser.getUsername(),loginUser.getPassword());
            return user;
        } catch (DataAccessException e) {
            //返回user包含用户全部数据，没有查询到，返回null
            return null;
        }
    }
}

**创建Loginservlet,判断数据库是否有信息，再进行转发**

package itcast.servlet;
import itcast.dao.UserDao;
import itcast.domain.User;
import org.apache.commons.beanutils.BeanUtils;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
@WebServlet("/loginServlet")
public class LoginServlet 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 {
        //1.设置编码
        req.setCharacterEncoding("utf-8");
        //2.获取所有请求参数，使用beanUtil.jar
        Map<String ,String[]> map=req.getParameterMap();
        //3.创建User对象
        User loginUser=new User();
        //3.2使用BeanUtil封装
        try {
            BeanUtils.populate(loginUser,map);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        //4.调用USerDao的login方法
        UserDao dao=new UserDao();
        User user=dao.login(loginUser);
        //5.判断user
        if(user==null){
            req.getRequestDispatcher("/fail.html").forward(req,resp);
        }else{
            //登录成功，存储数据
            req.setAttribute("user",user);
            //转发
            req.getRequestDispatcher("/success.html").forward(req,resp);
        }
    }
}

druid.properties文件加载数据库

driverClassName = com.mysql.jdbc.Driver
url= jdbc:mysql://localhost:3306/yang?useSSL=false
username= root
password= 123456
initialSize=5
maxActive=10
maxWait=1000