SpringBoot下实现MongoDB字段类型转换器

1 目的

String

LocalDateTime

2 实现

• 先定义实体类

@Data // lombok

@Accessors(chain = true)

@Document(collection = "UserEntity")

public class User implements Serializable {

    @Id

    private String id;

    private String username;

    private String password;

    // java中为LocalDateTime，根据Spring Data MongoDB的介绍:

    // LocalDateTime -> MongoDB的{"date" : ISODate("2019-11-12T23:00:00.809Z")}

    private LocalDateTime birthDay;

}

• 定义Repository

public interface UserRepository extends MongoRepository<UserEntity, String>{

}

• 定义转换器

// Direction: Java -> MongoDB

@WritingConverter

public class DateToString implements Converter<LocalDateTime, String> {

    @Override

    public String convert(LocalDateTime source) {

        return source.toString() + 'Z';

    }

}

// Direction: MongoDB -> Java

@ReadingConverter

public class StringToDate implements Converter<String, LocalDateTime> {

    @Override

    public LocalDateTime convert(String source) {

        return LocalDateTime.parse(source,DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"));

    }

}

• 注册转换器

@Configuration

public class MongoConfig {

    @Bean

    public CustomConversions customConversions() {

        List<Converter<?, ?>> converterList = new ArrayList<Converter<?, ?>>();

        converterList.add(new DateToString());

        converterList.add(new StringToDate());

        return new CustomConversions(converterList);

    }

}

• 最后测试

@RunWith(SpringRunner.class)

@SpringBootTest

public class UserDaoTest {

    @Autowired

    private UserRepository userRepository;

    @Test

    public void testSaveUser() {

        UserEntity user = new UserEntity();

        user.setUserName("test");

        user.setPassWord("test");

        user.setBirthDay(LocalDateTime.now());

        userRepository.saveUser(user);

    }

}

3 字符串的日期怎么区间查询？

public interface UserRepository extends MongoRepository<UserEntity, String>{

	List<UserEntity> findByBirthDayBetween(LocalDateTime start, LocalDateTime end);

}