Just Code It一、搭建SpringBoot项目1.1、file ——> new ——> project——> Spring Initializr——> next——> next——> next——> finish注意选择包依赖关系Web下的Spring Web。Template Engines下的Thymeleaf。SQL下的JDBC API、Spring Data JDBC、MySQL Driver。二、springboot整合mybatis.mysql2.1、整体结构2.2、设置所需要的依赖即pom.xml文件<?xml version="1.0" encoding="UTF-8"?><project xmlns="/POM/4.0.0" xmlns:xsi="/2001/XMLSchema-instance" xsi:schemaLocation="/POM/4.0.0 /xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.4.2</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>springboot-web04</groupId> <artifactId>demo</artifactId> <version>0.0.1-SNAPSHOT</version> <name>demo</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jdbc</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency><dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency><!--下面的都是我加的--> <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId> </dependency><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>2.1.3</version> </dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId> </dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.12</version><scope>provided</scope> </dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.2.1</version> </dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope><exclusions><exclusion> <groupId>org.junit.vintage</groupId> <artifactId>junit-vintage-engine</artifactId></exclusion></exclusions> </dependency> <dependency><groupId>org.xmlunit</groupId><artifactId>xmlunit-core</artifactId> </dependency> <dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.4.6</version> </dependency> </dependencies><build> <plugins> <plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build></project>2.3、设置application.yml文件与pplication.properties文件在resources目录下新建yml文件，用于存放数据库连接需要的一些数据spring: datasource: driver-class-name: com.mysql.cj.jdbc.Driver url: jdbc:mysql://localhost:3306/mybatis?serverTimezone=GMT%2B8&useSSL=true username: root #数据库password:sm1208#密码在application.properties文件中加入#端口号server.port=8080#druid数据库连接池type=com.alibaba.druid.pool.DruidDataSource#清除缓存spring.thymeleaf.cache=false#配置mappermybatis.mapper-locations=classpath:mapper/*.xml2.4、在pojo下的新建类UserLoginpackage springbootweb04.demo.pojo;import lombok.AllArgsConstructor;import lombok.Data;import lombok.NoArgsConstructor;@Data@AllArgsConstructor@NoArgsConstructorpublic class UserLogin { private String username; private String password;public String getUsername() { return username; }}2.5、新建数据库，名为mybatis，创建用户表，名为userLogin，创建username、password字段2.5.1、数据库名可以随意，不过要与application.yml文件中的一致2.5.2、IDEA中连接数据库Database——> +——> Data Source——> Mysql2.6、mapper层新建UserLoginMapper接口package springbootweb04.demo.mapper;import org.apache.ibatis.annotations.Mapper;import org.springframework.stereotype.Repository;import springbootweb04.demo.pojo.UserLogin;import java.util.List;@Mapper@Repositorypublic interface UserLoginMapper { //查询 public List<UserLogin> queryAll(); //添加数据 public int add(UserLogin userLogin); //根据用户名查询数据 public UserLogin queryByName(String username);}2.7、resources目录下的mapper目录在resources目录下新建mapper目录，并在这个目录下新建UserLoginMapper.xml文件<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE mapper PUBLIC "-////DTD Mapper 3.0//EN" "/dtd/mybatis-3-mapper.dtd"><mapper namespace="springbootweb04.demo.mapper.UserLoginMapper"> <select id="queryAll" resultType="springbootweb04.demo.pojo.UserLogin"> select * from userLogin </select><insert id="add" parameterType="springbootweb04.demo.pojo.UserLogin"> insert into userLogin values (#{username},#{password}) </insert><select id="queryByName" resultType="springbootweb04.demo.pojo.UserLogin"> select * from userLogin where username = #{username} </select></mapper>2.8、测试在test.Java.springbootweb04.demo类中，测试是否能联通数据库，没有报错说明成功。package springbootweb04.demo;import org.junit.jupiter.api.Test;import org.springframework.boot.test.context.SpringBootTest;import springbootweb04.demo.mapper.UserLoginMapper;import springbootweb04.demo.pojo.UserLogin;import org.springframework.beans.factory.annotation.Autowired;import javax.sql.DataSource;import java.sql.Connection;import java.sql.SQLException;import java.util.List;@SpringBootTestclass DemoApplicationTests { @Autowired DataSource dataSource; @Test void contextLoads() throws SQLException { System.out.println(dataSource.getClass()); Connection connection = dataSource.getConnection(); System.out.println(connection);//template模板，拿来即用 connection.close(); } @Autowired UserLoginMapper userLoginMapper; @Test public void toTest(){ List<UserLogin> userLogins = userLoginMapper.queryAll(); userLogins.forEach(e-> System.out.println(e)); }}2.9、services层在services下新建接口UserLoginServicesI和类UserLoginServicesImplUserLoginServicesI接口：package springbootweb04.demo.services;import springbootweb04.demo.pojo.UserLogin;import java.util.List;public interface UserLoginServicesI { //查询 public List<UserLogin> queryAll(); //添加数据 public int add(UserLogin userLogin); //根据用户名查询数据 public UserLogin queryByName(String username);}UserLoginServicesImpl类package springbootweb04.demo.services;import springbootweb04.demo.mapper.UserLoginMapper;import springbootweb04.demo.pojo.UserLogin;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import java.util.List;@Servicepublic class UserLoginServicesImpl implements UserLoginServicesI {@Autowired UserLoginMapper userLoginMapper; @Override public List<UserLogin> queryAll() { return userLoginMapper.queryAll(); }@Override public int add(UserLogin userLogin) { return userLoginMapper.add(userLogin); }@Override public UserLogin queryByName(String username) { return userLoginMapper.queryByName(username); }}2.A、controller层编写MyController类package springbootweb04.demo.controller;import springbootweb04.demo.pojo.UserLogin;import springbootweb04.demo.services.UserLoginServicesImpl;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.ui.Model;import org.springframework.web.bind.annotation.RequestMapping;@Controllerpublic class MyController { @Autowired UserLoginServicesImpl userLoginServicesImpl;@RequestMapping("/toLogin") public String toLogin(){ return "login"; }@RequestMapping("/LoginSuccess") public String LoginSuccess(Model model, UserLogin userLogin){ //先查询看该用户名是否存在 UserLogin userLogin1 = userLoginServicesImpl.queryByName(userLogin.getUsername()); if(userLogin1 != null){ // 如果查询的用户不为空 System.out.println(userLogin1.toString()); return "success"; } else{ //返回到登录页面 model.addAttribute("data","该用户不存在，请先注册"); return "login"; } } //登录界面 @RequestMapping("/toRegister") public String toRegister(){ return "register"; } @RequestMapping("/RegisterSuccess") public String toRegisterSuccess(Model model,UserLogin userLogin){ //将账号密码加入到数据库中 int add = userLoginServicesImpl.add(userLogin); System.out.println("数据插入成功！"); model.addAttribute("data","注册成功，请登录！"); return "login"; }}三、编写前端页面将以下三个页面放在templates下面login.html：登录页面<!DOCTYPE html><html lang="en" xmlns:th=""><head> <meta charset="UTF-8"> <title>Title</title></head><body style="background: aqua"><div align="center"> <br><br><h2>登录界面</h2><br><br> <span th:text="${data}" style="text-color:red;font-size: 10px"></span> <form method="get" action="/LoginSuccess"> 用户名:<input type="text" name="username" placeholder="请输入用户名" required/><br><br> 密码：<input type="text" name="password" placeholder="请输入密码" required/><br><br> <input type="submit" value="登录"> </form> <br> <form method="get" action="/toRegister"> <input type="submit" value="注册"> </form></div></body></html>register.html:注册页面<!DOCTYPE html><html lang="en" xmlns:th=""><head> <meta charset="UTF-8"> <title>Title</title></head><body style="background: aqua"><div align="center"> <br><br>注册界面<br><br> <form method="get" action="/RegisterSuccess"> 用户名:<input type="text" name="username" placeholder="请输入用户名" required/><br><br> 密码：<input type="text" name="password" placeholder="请输入密码" required/><br><br> 确认密码：<input type="text" name="password2" placeholder="请输入密码" required/><br><br> <input type="submit" value="注册"> </form></div></body></html>success.html：成功界面<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <title>Title</title></head><body></body></html>四、运行测试http://localhost:8080/toLogin
