普通方式

新建spring模块时引入如下内容：

启用devtools插件（热部署插件）

idea需要做如下配置

settings-build-compiler->勾选build project autoxxx选项

shift+alt+ctrl+/ ->registry->勾选compiler.automake.allow.when.app.running

在springboot插件里做如下配置

<build>
      <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <!--必须配置devtools-->
                    <fork>true</fork>
                </configuration>
            </plugin>
        </plugins>
    </build>

启用lombok（通过注解生成get/set等方法）

settings-plugins-搜索lombok-安装lombok插件

结构：

使用lombok插件的实体类

package com.example.bootssm1.domain;

import lombok.*;

import java.math.BigDecimal;
import java.util.Date;
//使用了lombok插件
@Data //自动生成get/set/toString等方法
@AllArgsConstructor//生成包含所有变量的构造方法
@NoArgsConstructor//生成无参的构造方法
public class BookInfo {
    private Integer bookId;
    private String bookName;
    private String bookAuthor;
    private BigDecimal bookPrice;
    private Date bookDate;
}

Mapper类

package com.example.bootssm1.mapper;

import com.example.bootssm1.domain.BookInfo;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

@Mapper // 把该接口生成的代理类的实例交给spring容器控制
public interface BookMapper {
    BookInfo getBookById(Integer bookId);
    int saveBook(BookInfo bookInfo);
    int batchBook(List<BookInfo> books);
}

Mapper配置xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC
        "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.bootssm1.mapper.BookMapper">
    <select id="getBookById" resultType="bookInfo">
        select book_id, book_name, book_author, book_price, book_date
          from t_book where book_id = #{id}
    </select>

    <insert id="saveBook" parameterType="bookInfo">
         insert into t_book(book_name, book_author, book_price, book_date)
          values(#{bookName}, #{bookAuthor}, #{bookPrice}, #{bookDate})
    </insert>
    
    <insert id="batchBook" parameterType="list">
        insert into t_book(book_name, book_author, book_price, book_date) 
          values 
          <foreach collection="books" item="val" open="(" close=")" separator=",">
              #{val.bookName}, #{val.bookAuthor}, #{val.bookPrice},#{val.bookDate}
          </foreach>
    </insert>
</mapper>

application.yml

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql:///testdb?useSSL=true
    username: root
    password: 123
mybatis:
  configuration:
    map-underscore-to-camel-case: true # book_id => bookId,book_name=> bookName 映射字段名到实体类的属性
  mapper-locations: classpath:mapper/*Mapper.xml  #指定mapper.xml的路径
  type-aliases-package: com.example.bootssm1.domain # 定义别名名称 默认为实体类类名首字母小写

测试类：

package com.example.bootssm1;

import com.example.bootssm1.domain.BookInfo;
import com.example.bootssm1.mapper.BookMapper;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import javax.annotation.Resource;

@RunWith(SpringRunner.class)
@SpringBootTest
public class BootSsm1ApplicationTests {

    @Resource
    private BookMapper bookMapper;

    @Test
    public void selectOne() {
        BookInfo book = bookMapper.getBookById(2);
        System.out.println(book);
    }

    @Test
    public void save() {
        BookInfo book = bookMapper.getBookById(2);
        book.setBookName("新书");
        int row = bookMapper.saveBook(book);
        Assert.assertEquals(1, row);
    }

}

整合tk.mybatis

结构：

pom引入依赖

        <dependency>
            <groupId>tk.mybatis</groupId>
            <artifactId>mapper-spring-boot-starter</artifactId>
            <version>2.0.4</version>
        </dependency>

BaseMapper

package com.example.bootssm2.common;

import tk.mybatis.mapper.common.Mapper;
import tk.mybatis.mapper.common.MySqlMapper;

/**
 * 项目中所有Mapper类的父类
 * @param <T>
 */
public interface BaseMapper<T> extends Mapper<T>, MySqlMapper<T> {
}

实体类：

package com.example.bootssm2.domain;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import javax.persistence.Id;
import javax.persistence.Table;
import java.math.BigDecimal;
import java.util.Date;

@Data
@AllArgsConstructor
@NoArgsConstructor
@Table(name = "t_book")//设定表名
public class BookInfo {
    @Id // 设定为主键
    private Integer bookId;
    private String bookName;
    private String bookAuthor;
    private BigDecimal bookPrice;
    private Date bookDate;
}

具体Mapper（只要继承BaseMapper即可）

package com.example.bootssm2.mapper;

import com.example.bootssm2.common.BaseMapper;
import com.example.bootssm2.domain.BookInfo;

public interface BookInfoMapper extends BaseMapper<BookInfo> {

}