Spring-boot-mybatis

1. sql

   DROP TABLE IF EXISTS `t_menu`;
   CREATE TABLE `t_menu`
   (
       `menu_id`   bigint       NOT NULL AUTO_INCREMENT,
       `parent_id` bigint       NOT NULL COMMENT '父菜单ID，一级菜单为0',
       `name`      varchar(50)  NOT NULL COMMENT '菜单名称',
       `url`       varchar(200) NOT NULL COMMENT '菜单URL',
       `level`     int(2)       NOT NULL,
       `type`      int          NOT NULL COMMENT '类型   0：目录   1：菜单   2：按钮',
       `order` int          NOT NULL COMMENT '排序',
       PRIMARY KEY (`menu_id`)
   ) ENGINE = `InnoDB`
     DEFAULT CHARACTER SET utf8mb4 COMMENT ='菜单管理';
   

2. pom.xml

   <?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <parent>
       <artifactId>springboot</artifactId>
       <groupId>com.shawn</groupId>
       <version>1.0-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
   
     <artifactId>spring-boot-mybatis-demo</artifactId>
   
     <dependencies>
       <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter</artifactId>
       </dependency>
       <dependency>
         <groupId>org.mybatis.spring.boot</groupId>
         <artifactId>mybatis-spring-boot-starter</artifactId>
       </dependency>
       <dependency>
         <groupId>mysql</groupId>
         <artifactId>mysql-connector-java</artifactId>
       </dependency>
       <dependency>
         <groupId>org.projectlombok</groupId>
         <artifactId>lombok</artifactId>
       </dependency>
     </dependencies>
   
     <build>
       <resources>
         <resource>
           <directory>src/main/java</directory>
           <includes>
             <include>
               **/*.xml
             </include>
           </includes>
         </resource>
       </resources>
     </build>
   </project>
   

3. application.yaml

   spring.datasource.url: jdbc:mysql://127.0.0.1:3306/spring-boot-demo?useUnicode=true&characterEncoding=UTF-8&useSSL=false&autoReconnect=true&failOverReadOnly=false&serverTimezone=GMT%2B8
   spring.datasource.username: root
   spring.datasource.password: 11111
   spring.datasource.driver-class-name: com.mysql.cj.jdbc.Driver
   
   mybatis.configuration.map-underscore-to-camel-case: true # 开启驼峰式命名
   mybatis.mapper-locations: classpath:mappers/*.xml # 配置mapper.xml
   mybatis.type-aliases-package: com.shawn.spring.boot.mybatis.entity # 省略实体类的报名
   mybatis.type-handlers-package: com.shawn.spring.boot.mybatis.handle # 添加处理器
   

4. 实体类

   @Data
   @NoArgsConstructor
   @AllArgsConstructor
   @Builder
   public class Menu {
   
     private long menuId;
     private long parentId;
     private String name;
     private String url;
     private int level;
     private MenuTypeEnum type; // 枚举
     private int order;
   }
   

   public interface BaseEnum {
   
     int getCode();
   
     String getName();
   
   }
   

   public enum MenuTypeEnum implements BaseEnum {
     CATALOG_TYPE(0, "目录"),
     MENU_TYPE(1, "菜单"),
     BUTTON_TYPE(2, "按钮");
   
     private int code;
     private String name;
   
     MenuTypeEnum(int code, String name) {
       this.code = code;
       this.name = name;
     }
   
     @Override
     public int getCode() {
       return code;
     }
   
     @Override
     public String getName() {
       return name;
     }
   }
   

5. mapper

   @Mapper
   @Repository
   public interface MenuMapper {
   
     @Insert(
         "insert into t_menu (`parent_id`, `name`, `url`, `level`, `type`, `order`) values "
             + " (#{menu.parentId}, #{menu.name}, #{menu.url}, #{menu.level}, #{menu.type}, #{menu.order})")
     @Options(useGeneratedKeys = true)
     int insert(@Param("menu") Menu menu);
   
     int update(@Param("menu") Menu newMenu);
   
     @Delete("delete from t_menu where menu_id = #{id}")
     int delete(@Param("id") long id);
   
     @Select("select * from t_menu")
     List<Menu> selectAll();
   
     @Select("SELECT * FROM t_menu WHERE menu_id = #{id}")
     Menu selectById(@Param("id") Long id);
   }
   

   <!-- 在resources/mappers 目录下创建一个xml文件 -->
   <?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.shawn.spring.boot.mybatis.mapper.MenuMapper">
   
     <update id="update" parameterType="Menu">
       update `t_menu` set `name` = #{menu.name},
       `url` = #{menu.url},
       `level` = #{menu.level},
       `type` = #{menu.type},
       `order` = #{menu.order}
       where `menu_id` = #{menu.menuId}
     </update>
   
   </mapper>
   

6. service

   @Service
   public class MenuServiceImpl implements MenuService {
   
     @Autowired private MenuMapper mapper;
   
     @Override
     public void insert(Menu menu) {
       mapper.insert(menu);
     }
   
     @Override
     public void update(Menu menu) {
       mapper.update(menu);
     }
   
     @Override
     public void delete(long id) {
       mapper.delete(id);
     }
   
     @Override
     public List<Menu> findAll() {
       return mapper.selectAll();
     }
   
     @Override
     public Menu findById(long id) {
       return mapper.selectById(id);
     }
   }
   

7. handle

   // enum类型处理器（暂时不通用）
   public class EnumTypeHandler<E extends Enum<?> & BaseEnum> extends BaseTypeHandler<BaseEnum> {
   
     @Override
     public void setNonNullParameter(
         PreparedStatement ps, int i, BaseEnum parameter, JdbcType jdbcType) throws SQLException {
       ps.setInt(i, parameter.getCode());
     }
   
     @Override
     public BaseEnum getNullableResult(ResultSet rs, String columnName) throws SQLException {
       int code = rs.getInt(columnName);
       return rs.wasNull() ? null : EnumUtil.codeOf(MenuTypeEnum.class, code);
     }
   
     @Override
     public BaseEnum getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
       int code = rs.getInt(columnIndex);
       return rs.wasNull() ? null : EnumUtil.codeOf(MenuTypeEnum.class, code);
     }
   
     @Override
     public BaseEnum getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
       int code = cs.getInt(columnIndex);
       return cs.wasNull() ? null : EnumUtil.codeOf(MenuTypeEnum.class, code);
     }
   }
   

8. runner

   @Component
   @Slf4j
   public class MybatisRunner implements ApplicationRunner {
   
     @Autowired private MenuService service;
   
     @Override
     public void run(ApplicationArguments args) throws Exception {
       log.info("test insert");
       testInsert();
       log.info("test update");
       testUpdate();
       log.info("test find all");
       testFindAll();
       log.info("test find by id");
       testFindById();
       log.info("test delete");
       testDelete();
       log.info("test find by id");
       testFindById();
     }
   
     private void testInsert() {
       Menu menu =
           Menu.builder()
               .parentId(0)
               .name("test")
               .level(1)
               .type(MenuTypeEnum.CATALOG_TYPE)
               .url("/test")
               .order(1)
               .build();
       service.insert(menu);
     }
   
     private void testUpdate() {
       Menu newMenu =
           Menu.builder()
               .menuId(1)
               .name("test2")
               .level(2)
               .type(MenuTypeEnum.CATALOG_TYPE)
               .url("/test2")
               .order(2)
               .build();
       service.update(newMenu);
     }
   
     private void testDelete() {
       service.delete(1);
     }
   
     private void testFindAll() {
       service.findAll().forEach(menu -> log.info(menu.toString()));
     }
   
     private void testFindById() {
       Menu menu = service.findById(3);
       if (menu == null) {
         log.warn("not found, id: {}", 3);
       } else {
         log.info(menu.toString());
       }
     }
   }
   

9. main class

   @SpringBootApplication
   @MapperScan("com.shawn.spring.boot.mybatis.mapper")
   public class MybatisApplication {
   
     public static void main(String[] args) {
       SpringApplication.run(MybatisApplication.class, args);
     }
   }