一、新建一个spring-boot项目 demo

项目结构与文件的含义：

二、项目编译入口代码 DemoApplication.java

@SpringBootApplication
//@EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class})
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

三、配置pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>
    <properties>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

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


        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>


        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.30</version>
        </dependency>

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


        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.11</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.2</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>6.0.2</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

四、连接MySQL数据库的配置

spring:
  datasource:
    #url: jdbc:mysql://[ip]:[port]/[name]?useSSL=false&useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true&allowPublicKeyRetrieval=true&serverTimezone=Asia/Shanghai
    url: jdbc:mysql://localhost:3306/exmaple?serverTimezone=UTC&characterEncoding=UTF-8
    username: root
    password:
    driver-class-name: com.mysql.cj.jdbc.Driver

五、使用JdbcTemplate 获取数据库数据

1、exmaple_userinfo表的数据

2、实现查表获取数据

@Repository
public class ClassInfoBean implements UserInfoDao {

    @Autowired
    JdbcTemplate jdbcTemplate ;

    @Override
    public List<Map<String, Object>> userInfo() {
        List<Map<String, Object>> list =new ArrayList<>() ;
        String sql = "select * from exmaple_userinfo";
        List<Map<String, Object>> l = jdbcTemplate.queryForList(sql);
        if (l!=null && l.size()>0){
            list.addAll(l);
        }
        return list;
    }
}

六、定义一个post请求接口 http:localhost:8000/login/pwd2

    /**
     * post 对象
     *
     * @return
     */
    @ResponseBody
    @PostMapping("/pwd2")
    public Map loginByPwd1(@RequestBody PostUserBean postUserBean){
        Map map = new HashMap() ;
        if (postUserBean == null || postUserBean.getName() == null ||!postUserBean.getName().equals("邱工")){
            map.put("msg","请传入{“Name:邱工”}");
        } else {
            map.put("classInfo",classInfoBean.userInfo());
        }
        return map;
    }

七、使用postman测试接口

八、在编译的时候可能出现端口被占用，那么以下是解决办法的一种 ，当然还有其他方法解决此问题，如直接更换端口号就行了。

1.查看该端口的进程（我的是8080）：netstat -ano|findstr 8080

2.kill该进程：taskkill /pid 14376 -f