Spring Boot整合Mybatis - 笔记

1. 创建数据库表并插入两条语句

   create database testdb default character set utf8;
   use testdb;
   create table book(
       id int(11) not null auto_increment,
       name varchar(128) default null,
       author varchar(64) default null,
       primary key (id)
   )engine=innodb default charset=utf8;
   insert into book values(1,'书1','作者1') (2,'书2','作者2');
   

2. 创建Spring Boot项目，添加Mybatis依赖、数据库驱动依赖、数据库连接池依赖。

   <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>2.1.0</version>
   </dependency>
   
   <dependency>
       <groupId>mysql</groupId>
       <artifactId>mysql-connector-java</artifactId>
   </dependency>
   
   <dependency>
       <groupId>com.alibaba</groupId>
       <artifactId>druid</artifactId>
       <version>1.1.20</version>
   </dependency>
   

3. 在application.properties中配置数据库连接信息，记得url中必须配置时区，否则报错！

   #数据库连接
   spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
   spring.datasource.url=jdbc:mysql://localhost:3306/chapter05?serverTimezone=UTC
   spring.datasource.username=xxxx
   spring.datasource.password=xxxx
   

4. 创建实体类Book

   package cn.cyj.data.entity;
   
   public class Book {
   
       private Integer id;
       private String name;
       private String author;
       
       //省略setters、getters、toString等
   }
   

5. 创建数据库访问层BookMapper

   package cn.cyj.data.mapper;
   
   import cn.cyj.data.entity.Book;
   import org.apache.ibatis.annotations.Mapper;
   
   import java.util.List;
   
   @Mapper
   public interface BookMapper {
       int addBook(Book book);
       int deleteBookById(Integer id);
       int updateBookById(Book book);
       Book getBookById(Integer id);
       List<Book> getAllBooks();
   }
   

6. 创建BookMapper.xml实现BookMapper接口中的方法

   BookMapper.xml与BookMapper同级

   <?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="cn.cyj.data.mapper.BookMapper">
       <insert id="addBook" parameterType="cn.cyj.data.entity.Book">
           INSERT INTO BOOK(NAME,AUTHOR) VALUES(#{name},#{author})
       </insert>
   
       <delete id="deleteBookById" parameterType="int">
           DELETE FROM BOOK WHERE id = #{id}
       </delete>
   
       <update id="updateBookById" parameterType="cn.cyj.data.entity.Book">
           UPDATE book SET name = #{name} , author = #{author} where id=#{id}
       </update>
   
       <select id="getBookById" parameterType="int" resultType="cn.cyj.data.entity.Book">
           SELECT * FROM book WHERE id = #{id}
       </select>
   
       <select id="getAllBooks" resultType="cn.cyj.data.entity.Book">
           SELECT * FROM book
       </select>
   </mapper>
   

   • id对应BookMapper接口中的方法名
   • parameterType对应方法的参数类型
   • resultType对应方法的返回值类型
   • #{}用来代替接口中的参数，实体类中的属性可以直接通过#{实体类属性名}获取

7. 创建BookService

   package cn.cyj.data.service;
   
   import cn.cyj.data.entity.Book;
   import cn.cyj.data.mapper.BookMapper;
   import org.springframework.beans.factory.annotation.Autowired;
   import org.springframework.stereotype.Service;
   
   import java.util.List;
   
   @Service
   public class BookService {
       
       @Autowired
       BookMapper bookMapper;
       
       public int addBook(Book book){
           return bookMapper.addBook(book);
       }
   
       public int updateBook(Book book){
           return bookMapper.updateBookById(book);
       }
   
       public int deleteBookById(Integer id){
           return bookMapper.deleteBookById(id);
       }
   
       public Book getBookById(Integer id){
           return bookMapper.getBookById(id);
       }
   
       public List<Book> getAllBooks(){
           return bookMapper.getAllBooks();
       }
   }
   

8. 创建BookController

   package cn.cyj.data.controller;
   
   import cn.cyj.data.entity.Book;
   import cn.cyj.data.service.BookService;
   import org.springframework.beans.factory.annotation.Autowired;
   import org.springframework.web.bind.annotation.RequestMapping;
   import org.springframework.web.bind.annotation.RestController;
   
   import java.util.List;
   
   @RestController
   @RequestMapping("/book")
   public class BookController {
   
       @Autowired
       BookService bookService;
   
       @RequestMapping("/test")
       public void bookTest(){
           Book book1 = new Book();
           book1.setName("黄金时代");
           book1.setAuthor("王小波");
           int i = bookService.addBook(book1);
           System.out.println("addBook>>>" + i );
   
           Book book2 = new Book();
           book2.setId(1);
           book2.setName("我的新书2");
           book2.setAuthor("我2");
           int j = bookService.updateBook(book2);
           System.out.println("updateBook>>>" + j);
   
           Book book3 = bookService.getBookById(8);
           System.out.println("book:" + book3.toString());
   
           int k = bookService.deleteBookById(8);
           System.out.println("deleteByBookId>>>" + k);
   
           List<Book> books = bookService.getAllBooks();
           System.out.println(books.toString());
       }
   }
   

9. 上面的BookMapper.xml文件在包下，Maven扫描不到，因此要在pom.xml里重新指明资源文件位置。

   <build>
       <resources>
           <resource>
               <directory>src/main/java</directory>
               <includes>
                   <include>**/*.xml</include>
               </includes>
           </resource>
           <resource>
               <directory>src/main/resources</directory>
           </resource>
       </resources>
   </build>
   

------------------------ 完结！撒花 ✿✿ヽ(°▽°)ノ✿ ------------------------