1新建项目

2选择jdk版本，和包名

3选择添加依赖

4查看pom文件，并添加resouces插件

	<!--resources插件-->
		<resources>
			<resource>
				<directory>src/main/resources</directory>
				<includes>
					<include>**/*.*</include>
				</includes>
			</resource>

最终文件

<?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>2.6.1</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.hry</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-jdbc</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>2.2.0</version>
		</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>
	</dependencies>

	<build>

		<!--resources插件-->
		<resources>
			<resource>
				<directory>src/main/resources</directory>
				<includes>
					<include>**/*.*</include>
				</includes>
			</resource>
		</resources>
		
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

5配置application.properties文件

#设置端口号
server.port=8080
#设置访问应用上下文路径， contextpath
server.servlet.context-path=/

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=admin
spring.datasource.url=jdbc:mysql://localhost:3306/ssmbuild?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=UTC&allowMultiQueries=true

#druid配置
#spring.datasource.type=com.alibaba.druid.pool.DruidDataSource

#mybaits配置
#指定mapper文件的位置
mybatis.mapper-locations=classpath:mapper/*.xml
mybatis.type-aliases-package=com/hry/pojo
#指定mybatis的日志
mybatis.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl

备注此文件可改成yml文件

6创建项目结构

7然后在启动行中添加@MapperScan(basePackages ="com.hry.mapper")扫描包

package com.hry;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan(basePackages ="com.hry.mapper")
public class DemoApplication {

	public static void main(String[] args) {
		SpringApplication.run(DemoApplication.class, args);
	}

}

8启动运行

备注：项目结构中的各类的代码，注意要创建在对应的包下

BooksController

package com.hry.controller;

import com.hry.pojo.Books;
import com.hry.service.BooksService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("books")
public class BooksController {
    @Autowired
    BooksService booksService;

    @RequestMapping("selectByid")
    public Books selectById(@RequestParam("cid") Integer id){
        return booksService.selectById(id);
    }

}

BooksMapper

package com.hry.mapper;

import com.hry.pojo.Books;


public interface BooksMapper {
    int deleteByPrimaryKey(Integer bookid);

    int insert(Books record);

    int insertSelective(Books record);

    Books selectByPrimaryKey(Integer bookid);

    int updateByPrimaryKeySelective(Books record);

    int updateByPrimaryKey(Books record);
}

Books

package com.hry.pojo;

public class Books {
    private Integer bookid;

    private String bookname;

    private Integer bookcounts;

    private String detail;

    public Integer getBookid() {
        return bookid;
    }

    public void setBookid(Integer bookid) {
        this.bookid = bookid;
    }

    public String getBookname() {
        return bookname;
    }

    public void setBookname(String bookname) {
        this.bookname = bookname == null ? null : bookname.trim();
    }

    public Integer getBookcounts() {
        return bookcounts;
    }

    public void setBookcounts(Integer bookcounts) {
        this.bookcounts = bookcounts;
    }

    public String getDetail() {
        return detail;
    }

    public void setDetail(String detail) {
        this.detail = detail == null ? null : detail.trim();
    }
}

BooksService

package com.hry.service;

import com.hry.pojo.Books;

public interface BooksService {
    Books selectById(Integer id);
}

BooksServiceimpl

package com.hry.service.impl;

import com.hry.mapper.BooksMapper;
import com.hry.pojo.Books;
import com.hry.service.BooksService;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

@Service
public class BooksServiceImpl implements BooksService {
    @Resource
    BooksMapper booksMapper;

    @Override
    public Books selectById(Integer id) {
        return booksMapper.selectByPrimaryKey(id);
    }
}

数据库代码，建立ssmbuild的数据库，运行下面代码

-- ----------------------------
-- Table structure for `books`
-- ----------------------------
DROP TABLE IF EXISTS `books`;
CREATE TABLE `books` (
  `bookID` int(10) NOT NULL AUTO_INCREMENT COMMENT '书id',
  `bookName` varchar(100) NOT NULL COMMENT '书名',
  `bookCounts` int(11) NOT NULL COMMENT '数量',
  `detail` varchar(200) NOT NULL COMMENT '描述',
  PRIMARY KEY (`bookID`),
  KEY `bookID` (`bookID`)
) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of books
-- ----------------------------
INSERT INTO `books` VALUES ('1', 'Java', '1', '从入门到放弃');
INSERT INTO `books` VALUES ('2', 'MySQL', '10', '从删库到跑路');
INSERT INTO `books` VALUES ('3', 'Linux', '5', '从进门到进牢');
INSERT INTO `books` VALUES ('6', 'hjfhfg', '123', '东方闪');