【Mybatis】mybatis登录实例

pom.xml

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>javax.servlet.jsp-api</artifactId>
            <version>2.3.1</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>

登录的JSP页面：

<%--
  Created by IntelliJ IDEA.
  User: Super
  Date: 2019/8/11
  Time: 21:07
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>主页-登录页面</title>
</head>
<body>
<form action="login" method="post">
    姓名：<input type="text" name="username" id="username"><br>
    密码：<input type="password" name="userpass" id="userpass"><br>
    <input type="submit" value="登录">
</form>
</body>
</html>

web.xml中的servlet配置:

    <servlet>
        <servlet-name>Login</servlet-name>
        <servlet-class>com.hj.servlet.LoginServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>Login</servlet-name>
        <url-pattern>/login</url-pattern>
    </servlet-mapping>

LoginServlet类：

package com.hj.servlet;

import com.hj.bean.Users;
import com.hj.dao.UserDao;

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;

// @WebServlet(name = "LoginServlet")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Users user = new Users();
        user.setUsername(request.getParameter("username"));
        user.setUserpass(request.getParameter("userpass"));
        UserDao userDao = new UserDao();
        Users loginUser = userDao.loginCheck(user);
        if (loginUser != null) {
            request.getRequestDispatcher("success.jsp").forward(request, response);
        }else {
            request.getRequestDispatcher("fail.jsp").forward(request, response);
        }

    }

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

User类：

package com.hj.bean;

public class Users {
    private int id;
    private String username;
    private String userpass;
    private String nickname;

    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 getUserpass() {
        return userpass;
    }

    public void setUserpass(String userpass) {
        this.userpass = userpass;
    }

    public String getNickname() {
        return nickname;
    }

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

UserDao

package com.hj.dao;

import com.hj.bean.Users;
import com.hj.utils.SqlSessionFactoryUtils;
import org.apache.ibatis.session.SqlSession;

import java.util.List;

public class UserDao {
    private SqlSession sqlSession;
    private List<Users> list;
    private Users users;

    private SqlSession getSession(){
        sqlSession = SqlSessionFactoryUtils.getSqlSessionFactory().openSession();
        return sqlSession;
    }

    public Users loginCheck(Users user){
        try {
            System.out.println("登录查询中...");
             this.users = getSession().selectOne("loginCheck", user);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            sqlSession.close();
        }
        return this.users;
    }

}

-------------------------工具类和Listener---------------------

工具类，用于获取SqlSession，启动和关闭SqlSessionFactory：

package com.hj.utils;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

public class SqlSessionFactoryUtils {
    private static String RESOURCE = "mybatis.xml";
    private static SqlSessionFactory sqlSessionFactory;
    private static ThreadLocal<SqlSession> threadLocal = new ThreadLocal<SqlSession>();

    /**
     * 初始化时候新建工厂
     */
    public static void initSqlSessionFactory(){
        try {
            InputStream is = Resources.getResourceAsStream(RESOURCE);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);

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

    /**
     * 获取SqlSessionFactory的方法
     * @return
     */
    public static SqlSessionFactory getSqlSessionFactory(){
        return sqlSessionFactory;
    }

    /**
     * 关闭session
     */
    public static void close(){
        SqlSession session = threadLocal.get();
        if (session != null) {
            threadLocal.set(null);

        }
    }


}

Listener：

package com.hj.listener;


import com.hj.utils.SqlSessionFactoryUtils;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;

@WebListener
public class InitSqlSessionListener implements ServletContextListener {
    public void contextInitialized(ServletContextEvent servletContextEvent) {
        System.out.println("容器加载中,初始化SqlSessionFactory...");
        SqlSessionFactoryUtils.initSqlSessionFactory();
    }

    public void contextDestroyed(ServletContextEvent servletContextEvent) {
        System.out.println("容器销毁中，关闭SqlSession对象...");
        SqlSessionFactoryUtils.close();
    }
}

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原文地址：https://www.cnblogs.com/to-red/p/11337298.html