MyBatis整合(SpringBoot)

1. 导入依赖

             <dependency>
               <groupId>org.mybatis.spring.boot</groupId>
               <artifactId>mybatis-spring-boot-starter</artifactId>
               <version>2.1.2</version>
           </dependency>
           <dependency>
               <groupId>com.alibaba</groupId>
               <artifactId>druid</artifactId>
               <version>1.1.22</version>
           </dependency>

    

2. 创建数据库访问层(Mapper)

   @Mapper
   public interface BookMapper {
       int addBook(Book book);
       int deleteBookById(Integer id);
       int updateBookById(Book book);
       Book getBookById(Integer id);
       List<Book> getAllBooks();
   }

    

3. 创建对应的Mapper.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.batac.summer.Mapper.BookMapper">
       <insert id="addBook" parameterType="com.batac.summer.bean.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="com.batac.summer.bean.Book">
           update book set name=#{name},author=#{author} where id=#{id}
       </update>
   
       <select id="getBookById" parameterType="int" resultType="com.batac.summer.bean.Book">
           select * from book where id=#{id}
       </select>
       <select id="getAllBooks" resultType="com.batac.summer.bean.Book">
           select * from book
       </select>
   </mapper>

    

4. service与controller测试

   @Service
   public class BookService {
   
   //    @Autowired
   //    BookDao bookDao;
   
       @Autowired
       private  BookMapper bookMapper;
   
       public int addBoot(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();
       }
   
   }

   @RestController
   public class BookController {
       @Autowired
       BookService bookService;
   
      @GetMapping("/bookOps")
       public void  bookOps(){
           Book b1 = new Book();
           b1.setName("西厢记");
           b1.setAuthor("王师傅");
           int i = bookService.addBoot(b1);
          System.out.println("addBoot>>>"+i);
   
          Book b2 = new Book();
          b2.setId(1);
          b2.setName("朝花夕拾");
          b2.setAuthor("鲁迅");
          int i2=bookService.updateBook(b2);
          System.out.println("updateBook>>>"+i2);
   
          Book b3=bookService.getBookByID(1);
          System.out.println("getBookByID>>>"+b3);
   
          List<Book>list = bookService.getAllBooks();
          System.out.println("getAllBooks>>>"+list);
       }
       
   }

    

在Maven工程中, XML配置文件建议卸载resources目录下, 但是上文中的Mapper.xml文件写在了包下, Maven在运行时会忽略包下的XML文件, 因此需要在pom.xml文件中重新指明资源文件位置, 配置如下:

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

 注意: 有两种方式指明该类是一个Mapper: 第一种是如前面的代码所示, 在BookMapper上添加@Mapper注解, 表明该接口是一个MyBatis中的Mapper, 这种方式要在每一个Mapper上都添加注解, 还有一种简单的方式是在配置类上添加MapperScan("com.batac.summer.mapper")注解, 表示扫描com.batac.summer.mapper包下所有的接口作为Mapper, 这样就不用在每个接口上配置@Mapper注解了。