写在前面
之前用 JPA 体验了一下 SpringBoot（这篇），最近也想试试 MyBatis，就在上一个 demo 的基础上改用 MyBatis 实现了一下。
项目结构
主要代码配置
源码同样丢 github 上去了，可以点这里查看
下面列一些主要的代码和配置
0. application.yml
spring:
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://127.0.0.1:3306/SpringBootDemo?autoReconnect=true&useSSL=false&useUnicode=true&characterEncoding=utf-8
username: root
password: mysql
server:
port: 8080
mybatis:
type-aliases-package: com.priesttomb.demo.vo
mapper-locations: classpath:mybatis/mapper/*.xml
这里简单的配置了 MyBatis 的别名包路径，和相关 mapper.xml 文件的路径
稍微测试了一下，如果在 mapper.xml 里把各个实体类的路径写完整的话，这里的 type-aliases-package 可以不用配（比如下面的 BookMapper.xml 中，Book 类的路径都带了完整的包路径）
1. BookMapper.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.priesttomb.demo.mapper.IBookMapper">
<resultMap type="com.priesttomb.demo.vo.Book" id="BaseResultMap">
<result column="id" property="id" />
<result column="name" property="name" />
<result column="price" property="price" />
</resultMap>
<sql id="Base_Column">
id, name, price
</sql>
<select id="findAll" resultMap="BaseResultMap">
select
<include refid="Base_Column" />
from book
</select>
<select id="findById" resultMap="BaseResultMap" parameterType="int">
select
<include refid="Base_Column" />
from book
where id = #{id}
</select>
<select id="findByName" resultMap="BaseResultMap" parameterType="java.lang.String">
select
<include refid="Base_Column" />
from book
where name = #{name}
</select>
<insert id="save" useGeneratedKeys="true" keyProperty="id" parameterType="com.priesttomb.demo.vo.Book">
insert into book (name, price)
values (#{name}, #{price})
</insert>
<delete id="deleteById">
delete from book where id = #{id}
</delete>
<update id="updateBook" parameterType="com.priesttomb.demo.vo.Book">
update book
<set>
<if test="name != null and name != ''">name = #{name},</if>
<if test="price != null">price = #{price}</if>
</set>
where id = #{id}
</update>
</mapper>
mapper.xml 这儿就是配一下 sql 了，<insert> 和 <update> 需要配一下 parameterType，因为到时候接收的参数就是一个实体类对象
2. SpringBootMySqlMyBatisApplication.java
package com.priesttomb.demo;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.priesttomb.demo.mapper")
public class SpringBootMySqlMyBatisApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBootMySqlMyBatisApplication.class, args);
}
}
启动类这里可以加一个 @MapperScan 注解，要么就直接在对应的 Mapper 类上加 @Mapper 注解，都行
3. IBookMapper.java
package com.priesttomb.demo.mapper;
import java.util.List;
import org.apache.ibatis.annotations.Mapper;
import com.priesttomb.demo.vo.Book;
//@Mapper
public interface IBookMapper {
Long save(Book book);
List<Book> findAll();
Book findById(Integer id);
Book findByName(String name);
void deleteById(Integer id);
int updateBook(Book book);
}
正如上面所说，也可以直接在这儿加 @Mapper 注解
4. BookController.java
package com.priesttomb.demo.controller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import com.priesttomb.demo.service.IBookService;
import com.priesttomb.demo.vo.Book;
@RestController
public class BookController {
@Autowired
private IBookService bookService;
/**
* 添加一本书（用form-data传来的各个字段）
* @param name
* @param price
*/
// @PostMapping(value = "/book")
// public void addBook(@RequestParam(value="name") String name,@RequestParam(value="price") Integer price) {
// Book book = new Book(name, price);
// bookService.saveBook(book);
// }
/**
* 添加一本书（使用json格式直接传递一个对象）
*/
@PostMapping(value = "/book", consumes = "application/json")
public void addBook(@RequestBody Book book) {
bookService.saveBook(book);
}
/**
* 获取所有的书
* @return
*/
@GetMapping(value = "/book")
public List<Book> getAllBooks() {
return bookService.getAllBooks();
}
/**
* 根据书的id获取书
* @param id
* @return
*/
@GetMapping(value = "/book/{id}")
public Book getBookById(@PathVariable("id") Integer id) {
return bookService.getBookById(id);
}
/**
* 根据书的id删除书
* @param id
*/
@DeleteMapping(value = "/book/{id}")
public void delBookById(@PathVariable("id") Integer id) {
bookService.delBookById(id);
}
/**
* 根据书名查书
* @param name
* @return
*/
@GetMapping(value = "/book/name/{name}")
public Book findByName(@PathVariable("name") String name) {
return bookService.findByName(name);
}
/**
* 更新一本书（使用json格式直接传递一个对象）
* @param book
* @param id
* @return
*/
@PutMapping(value = "/book/{id}", consumes = "application/json")
public String updateById(@RequestBody Book book, @PathVariable("id") Integer id) {
int result = bookService.updateBook(book);
return result == 1 ? "succ" : "fail";
}
}
新增和更新时传递 Book 对象，这里考虑了下用了 json
运行测试
还是用 Postman 测试，在使用 PUT 或者 POST 时，要使用 json 传递对象，就要设置下 Content-Type：
拼接对象：
测试正常，over