1. 创建项目：springboot_demo_4

在这里插入图片描述

在这里我们不勾选一些自动导入的依赖，我们通过手动配置pom.xml的依赖即可！

2. 编辑pom.xml文件

1.SpringBoot包(spring) 2.SpringMVC 3.MybatisPlus

<?xml version="1.0" encoding="UTF-8"?>
<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>4.0.0</modelVersion>

    <groupId>com.jt</groupId>
    <artifactId>springboot_demo_4</artifactId>
    <version>1.0-SNAPSHOT</version>

    <!--引入父级工程-->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.5</version>
        <relativePath/>
    </parent>

    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <!--thymeleaf导入模版工具类-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

        <!--SpringMVCjar包文件-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--热部署工具-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <!--lombok插件-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

        <!--测试包-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!--引入jdbc包-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

        <!--引入数据库驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

        <!--spring整合mybatis-plus -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.2</version>
        </dependency>
    </dependencies>

    <!--负责项目打包部署-->
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

3. 编辑yml配置文件

server:
  port: 8090

spring:
  datasource:
    url: jdbc:mysql://127.0.0.1:3306/jtadmin?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true
    username: root
    password: root

  #整合SpringMVC
  thymeleaf:
    #设置页面前缀
    prefix: classpath:/templates/
    #设置页面后缀
    suffix: .html
    #是否使用缓存
    cache: false

mybatis-plus:
  type-aliases-package: com.jt.pojo
  mapper-locations: classpath:/mappers/*.xml
  #开启驼峰映射
  configuration:
    map-underscore-to-camel-case: true

#添加MP日志  打印执行的sql
logging:
  level:
    com.jt.mapper: debug

主要配置如下：

端口号配置
数据库数据源配置
SpringMVC的配置
MP的映射配置
开启MP日志

4. 编辑POJO实体对象

package com.jt.pojo;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;
import lombok.experimental.Accessors;

@TableName("demo_user")
@Data
@Accessors(chain = true)
public class User {
    @TableId(type = IdType.AUTO)
    private Integer id;
    private String name;
    private String sex;
    private Integer age;
}

5. 编辑userList.html页面

<!DOCTYPE html>
<!--导入模板标签!!!!!-->
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>用户列表数据</title>
</head>
<body>
   <!--准备一个表格-->
    <table border="1px" align="center" width="800px">
        <tr align="center">
            <td colspan="4"><h3>用户列表</h3></td>
        </tr>
        <tr align="center">
            <td>ID</td>
            <td>名称</td>
            <td>年龄</td>
            <td>性别</td>
        </tr>
        <!--1.页面通过request对象 动态的获取userList数据 之后tr展现-->
        <tr align="center" th:each="user : ${userList}">
            <td th:text="${user.id}"></td>
            <td th:text="${user.name}"></td>
            <td th:text="${user.age}"></td>
            <td th:text="${user.sex}"></td>
        </tr>
    </table>
</body>
</html>

6. 编辑UserController

/**
 * 查询所有的用户列表数据,在userList.html中展现数据
 */
@RequestMapping("/userList")
public String userList(Model model){
    //1.查询业务层获取数据
    List<User> userList = userService.findAll();
    //2.将数据保存到Model对象中返回给页面
    model.addAttribute("userList",userList);
    return "userList";
}

7. 编辑UserService

@Service
public class UserServiceImpl implements UserService{

    @Autowired
    private UserMapper userMapper;

    @Override
    public List<User> findAll() {

        return userMapper.selectList(null);
    }
}

8. 编辑UserMapper

package com.jt.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.jt.pojo.User;

public interface UserMapper extends BaseMapper<User> {
}