Javaweb - 实例功能（上） - 用户登录界面实现（mybatis、maven、mysql、tomcat、servlet）
文章目录
- 用户登录
-
- 流程说明
- 准备环境
-
- 1-1.新建Maven web项目
- 1-2.写表单页面
-
- 注意
- 2-1.准备SQL表
- 2-2.创建User实体类
- 3-1.导入MyBatis坐标、MySQL驱动坐标
- 4-1.创建mybatis-config.xml核心配置文件
- 4-2.创建UserMapper接口
- 4-3.resources目录下建立mapper包映射
- 4-4.resources - mapper包下创建UserMapper.xml
- 开始编写代码
-
- 注解实现select语句
-
- 注意
- 编写loginServlet
-
- 注意
- 运行测试
-
- 500报错
- 测试成功
用户登录
流程说明
- 用户填写用户名密码，提交到LoginServlet
- 在LoginServlet使用 MyBatis查询数据库，验证用户名密码是否正确
- 如果正确，响应“登录成功”，如果错误，响应“登录失败”
准备环境
- 写静态页面到webapp目录下
- 创建servlet数据库，创建tb_user表，创建User实体类
- 导入MyBatis坐标，MySQL驱动坐标
- 创建mybatis-config.xml核心配置文件，UserMapper.xml映射文件，UserMapper接口
1-1.新建Maven web项目
手把手教程
Javaweb - tomcat入门简介、安装配置，到idea配置tomcat并使用_鬼鬼骑士的博客-CSDN博客
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0modelVersion>
<groupId>org.examplegroupId>
<artifactId>User_demo1artifactId>
<version>1.0-SNAPSHOTversion>
<packaging>warpackaging>
<build>
<plugins>
<plugin>
<groupId>org.apache.tomcat.mavengroupId>
<artifactId>tomcat7-maven-pluginartifactId>
<version>2.2version>
plugin>
plugins>
build>
project>
1-2.写表单页面
webapp包下
DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Documenttitle>
head>
<style type="text/css">
* {
margin: 0;
padding: 0;
}
div {
width: 400px;
height: 500px;
margin: 300px auto;
}
style>
<body>
<form action="/User_demo1/test1" method="get">
<div>
<span>Username：span>
<input type="text" name="username"/><br /><br>
<span>Password： span>
<input type="text" name="password"/>
<input type="submit" value="submit" />
div>
form>
body>
html>
注意
表单标签一定要用"name"命名，不然怎么识别
2-1.准备SQL表
数据库使名称为mybatis
drop table if exists tb_user;
Create table tb_user(
id int primary key auto_increment,
`username` varchar(20) unique,
password varchar(32)
);
insert into tb_user(username,password) values('zhangsan','123'),('lisi','234');
select * from tb_user;
2-2.创建User实体类
User实体类在com.taotao.pojo下
package com.taotao.pojo;
public class User {
private Integer id;
private String username;
private String password;
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", password='" + password + '\'' +
'}';
}
public Integer getId() {
return id;
}
public void setId(Integer 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;
}
}
3-1.导入MyBatis坐标、MySQL驱动坐标
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0modelVersion>
<groupId>org.examplegroupId>
<artifactId>User_demo1artifactId>
<version>1.0-SNAPSHOTversion>
<packaging>warpackaging>
<build>
<plugins>
<plugin>
<groupId>org.apache.tomcat.mavengroupId>
<artifactId>tomcat7-maven-pluginartifactId>
<version>2.2version>
plugin>
plugins>
build>
<dependencies>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatisartifactId>
<version>3.5.5version>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>5.1.32version>
dependency>
dependencies>
project>
4-1.创建mybatis-config.xml核心配置文件
文件放入到resources目录下
Mybatis - Mybatis简介到完善Idea配置Mybatis、以及idea连接Mysql数据库方法_鬼鬼骑士的博客-CSDN博客
DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql:///mybatis?useSSL=false&useServerPrepStates=true"/>
<property name="username" value="root"/>
<property name="password" value="12345"/>
dataSource>
environment>
environments>
<mappers>
<package name="com.taotao.mapper">package>
mappers>
configuration>
4-2.创建UserMapper接口
package com.taotao.mapper;
public interface UserMapper {
}
4-3.resources目录下建立mapper包映射
注意创建目录使用 /
4-4.resources - mapper包下创建UserMapper.xml
DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.taotao.mapper.UserMapper">
mapper>
开始编写代码
注解实现select语句
编写UserMapper接口方法
package com.taotao.mapper;
import com.taotao.pojo.User;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
public interface UserMapper {
/**
* 根据用户名和密码查询用户对象
* @param username
* @param password
* @return
*/
@Select("select * from tb_user where username = #{username} and password = #{password}")
User select(@Param("username") String username, @Param("password") String password);
}
注意
此步骤要先连接数据库，点右侧dase
编写loginServlet
写在web包下
package com.taotao.web;
import com.taotao.mapper.UserMapper;
import com.taotao.pojo.User;
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 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;
import java.io.InputStream;
import java.io.PrintWriter;
@SuppressWarnings({"all"})
@WebServlet("/test1")
public class LoginServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1.接收用户名和密码
String username = req.getParameter("username");
String password = req.getParameter("password");
//2.调用MyBatis完成查询
//2.1获取SqlSessionFactory对象
String resource = "mybatis.config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.2获取SqlSession对象
SqlSession sqlSession = sqlSessionFactory.openSession();
//2.3获取Mapper
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
//2.4调用方法
User user = userMapper.select(username, password);
//2.5释放资源
sqlSession.close();
//获取字符输出流，并设置content type
resp.setContentType("text/html;charset=utf-8");
PrintWriter writer = resp.getWriter();
//3.判断user释放为null
if(user != null){
//登录成功
writer.write("login successfully肥肥！！
");
}else{
//登录失败
writer.write("login failed..");
}
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doGet(req, resp);
}
}
注意
继承HttpServlet时，需要导入servlet工具类
编写pom.xml
<dependency>
<groupId>javax.servletgroupId>
<artifactId>javax.servlet-apiartifactId>
<version>3.1.0version>
dependency>
运行测试
500报错
看自己javaBug笔记解决
测试成功
