spring 配置 mybatis-plus

1. 添加 mybatis-plus 依赖

<dependency>
    <groupId>com.baomidou.mybatisplus</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.3.2</version>
</dependency>

2. 配置数据源

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatisplus?useSSL=false&useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
    username: root
    password: root

3. 配置 mybatis-plus

@Configuration
@MapperScan("com.example.mapper")
public class MybatisPlusConfig {

    @Autowired
    private DataSource dataSource;

    /**
     * 分页插件
     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        // 设置方言
        paginationInterceptor.setDbType(DbType.MYSQL);
        return paginationInterceptor;
    }

    /**
     * mybatis-plus SQL执行效率插件【生产环境可以关闭】
     */
    @Bean
    @Profile({"dev", "test"}) // 设置 dev test 环境开启
    public PerformanceInterceptor performanceInterceptor() {
        PerformanceInterceptor performanceInterceptor = new PerformanceInterceptor();
        performanceInterceptor.setMaxTime(1000); // SQL执行最大时长，超过自动停止运行，有助于发现问题。
        performanceInterceptor.setFormat(true); // SQL是否格式化，默认false。
        return performanceInterceptor;
    }

    @Bean
    public MybatisSqlSessionFactoryBean mybatisSqlSessionFactoryBean() {
        MybatisSqlSessionFactoryBean sessionFactory = new MybatisSqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSource);
        // 设置mapper文件扫描路径
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/*.xml"));
        // 设置mybatis配置文件路径
        sessionFactory.setConfigLocation(new ClassPathResource("mybatis-config.xml"));
        // 设置分页插件和SQL执行效率插件
        sessionFactory.setPlugins(new Interceptor[]{paginationInterceptor(), performanceInterceptor()});
        return sessionFactory;
    }

}

4. 配置实体类和 Mapper

@Data
public class User {

    private Long id;

    private String name;

    private Integer age;

    private String email;

    private Date createTime;

    private Date updateTime;

}

@Mapper
public interface UserMapper extends BaseMapper<User> {

}

5. 使用示例

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

    @Override
    public List<User> list() {
        return userMapper.selectList(null);
    }

    @Override
    public User getById(Long id) {
        return userMapper.selectById(id);
    }

    @Override
    public boolean save(User user) {
        return userMapper.insert(user) > 0;
    }

    @Override
    public boolean update(User user) {
        return userMapper.updateById(user) > 0;
    }

    @Override
    public boolean removeById(Long id) {
        return userMapper.deleteById(id) > 0;
    }

}