Servlet+Mybatis小练习Demo——用户登录注册

项目结构

 

数据表结构

  pom文件

    4.0.0

    org.example
    MavenWeb3
    1.0-SNAPSHOT
    war

    
        
            javax.servlet
            javax.servlet-api
            3.0.1
            
            provided
        
        
            commons-io
            commons-io
            2.4
        
        
            org.projectlombok
            lombok
            1.18.12
        
        
            org.mybatis
            mybatis
            3.5.6
        
        
            mysql
            mysql-connector-java
            5.1.8
        
    

    
        
            
                org.apache.tomcat.maven
                tomcat7-maven-plugin
                2.2
                
                    8080
                    
                    /MavenWeb3
                
            
        
    

 pojo

@Data//包括get、set、equals、hashCode、canEqual、toString、无参构造，没有有参构造
@NoArgsConstructor
public class User {
    private Integer id;
    private String name;
    private String password;
    private String email;
    private Date birthday;
    private String infoId;
    private String englishTeacher;

    public User(Integer id, String name, String password, String email, Date birthday, String infoId, String englishTeacher) {
        this.id = id;
        this.name = name;
        this.password = password;
        this.email = email;
        this.birthday = birthday;
        this.infoId = infoId;
        this.englishTeacher = englishTeacher;
    }
}

mybatis核心配置mybatis-config.xml 

mapper接口

public interface UserMapper {
    @Select("select * from users where name = #{name} and password = #{password}")
    User selectByNameAndPwd(@Param("name")String name,@Param("password")String password);

    @Select("select * from users where name = #{name}")
    User selectByName(@Param("name") String name);

    @Insert("insert into users(name,password,email,birthday,infoId,english_teacher)" +
            " values(#{name},#{password},#{email},#{birthday},#{infoId},#{englishTeacher});")
    int insert(User user);
}

sql映射文件UserMapper.xml

登录界面html

    
    



    
登录
    
用户名：


    
密  码：

    
    
    点击注册

注册界面html

    
    



    

        

            
用户名：
            

                

                用户名不太受欢迎
            
        
        

            
密码：
            

        
        

            
邮箱：
            

        
        

            
生日：
            

        
        

            
infoId
            

        
        

            
英语老师：
            

        
        

            

            
        
    

 登录的servlet

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("UTF-8");
        String name = req.getParameter("name");
        String password = req.getParameter("password");
        SqlSessionFactory sqlSessionFactory = SqlSessionFactoryUtils.getSqlSessionFactory();
        //2.获取SqlSession对象，用它来执行sql
        SqlSession sqlSession = sqlSessionFactory.openSession();
        //3.执行sql
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        User user = mapper.selectByNameAndPwd(name,password);
        resp.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=utf-8");
        PrintWriter writer = resp.getWriter();
        if (user != null){
            writer.write("login success!");
        }else{
            writer.write("login fail!");
        }
        //4.释放资源
        sqlSession.close();
    }
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

注册的servlet

@WebServlet("/registerServlet")
public class RegisterServlet extends HttpServlet {
    @SneakyThrows
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("UTF-8");
        String name = req.getParameter("name");
        String password = req.getParameter("password");
        String email = req.getParameter("email");
        String birthday = req.getParameter("birthday");
        String infoId = req.getParameter("infoId");
        String englishTeacher = req.getParameter("englishTeacher");
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Date birthdayDate = sdf.parse(birthday);
        User user = new User(null, name, password, email, birthdayDate, infoId, englishTeacher);
        //1.加载mybatis核心配置，获取SqlSessionFactory
        SqlSessionFactory sqlSessionFactory = SqlSessionFactoryUtils.getSqlSessionFactory();
        //2.获取SqlSession对象，用它来执行sql
        SqlSession sqlSession = sqlSessionFactory.openSession();
        //3.执行sql
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        User existUserName = mapper.selectByName(name);
        resp.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=utf-8");
        PrintWriter writer = resp.getWriter();
        if (existUserName ==null){
            int count = mapper.insert(user);
            sqlSession.commit();
            //4.释放资源
            sqlSession.close();
            writer.write("注册成功");
        }else{
            writer.write("用户名太受欢迎了");
        }
    }
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req,resp);
    }
}

SqlSessionFactoryUtils 

/**
 * 通过静态代码块使得该类再被JVM加载时仅执行唯一一次静态代码块中的内容，生成一个sqlSessionFactory对象保存在该类变量中
 * 后续直接通过public的getSqlSessionFactory方法拿到这个对象即可。避免重复频繁创建sqlSessionFactory对象的问题。
 */
public class SqlSessionFactoryUtils {
    private static SqlSessionFactory sqlSessionFactory;

    static {
        try {
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static SqlSessionFactory getSqlSessionFactory(){
        return sqlSessionFactory;
    }
}