问题
I'm using MongoDB and Spring over Kotlin and i want my application to populate a MongoDB collection upon startup. (and clean it every time it starts)
My question is, how can i populate the data one by one in order to be fault tolerant in case some of the data I'm populating with is problematic?
my code:
@Configuration
class IndicatorPopulator {
@Value("classpath:indicatorData.json")
private lateinit var data: Resource
@Autowired
private lateinit var indicatorRepository: IndicatorRepository
@Bean
@Autowired
fun repositoryPopulator(objectMapper: ObjectMapper): Jackson2RepositoryPopulatorFactoryBean {
val factory = Jackson2RepositoryPopulatorFactoryBean()
indicatorRepository.deleteAll()
factory.setMapper(objectMapper)
factory.setResources(arrayOf(data))
return factory
}
What I am looking for is something like:
@Bean
@Autowired
fun repositoryPopulator(objectMapper: ObjectMapper): Jackson2RepositoryPopulatorFactoryBean {
val factory = Jackson2RepositoryPopulatorFactoryBean()
indicatorRepository.deleteAll()
factory.setMapper(objectMapper)
val arrayOfResources: Array<Resource> = arrayOf(data)
for (resource in arrayOfResources){
try{
factory.setResources(resource)
} catch(e: Exception){
logger.log(e.message)
}
}
return factory
}
Any idea on how to do something like that would be helpful... Thanks in advance.
回答1:
There is no built in support for your ask but you can easily provide by tweaking few classes.
Add Custom Jackson 2 Reader
public class CustomJackson2ResourceReader implements ResourceReader {
private static final Logger logger = LoggerFactory.getLogger(CustomJackson2ResourceReader.class);
private final Jackson2ResourceReader resourceReader = new Jackson2ResourceReader();
@Override
public Object readFrom(Resource resource, ClassLoader classLoader) throws Exception {
Object result;
try {
result = resourceReader.readFrom(resource, classLoader);
} catch(Exception e) {
logger.warn("Can't read from resource", e);
return Collections.EMPTY_LIST;
}
return result;
}
}
Add Custom Jackson 2 Populator
public class CustomJackson2RepositoryPopulatorFactoryBean extends Jackson2RepositoryPopulatorFactoryBean {
@Override
protected ResourceReader getResourceReader() {
return new CustomJackson2ResourceReader();
}
}
Configuration
@SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
@Bean
public AbstractRepositoryPopulatorFactoryBean repositoryPopulator(ObjectMapper objectMapper, KeyValueRepository keyValueRepository) {
Jackson2RepositoryPopulatorFactoryBean factory = new CustomJackson2RepositoryPopulatorFactoryBean();
keyValueRepository.deleteAll();
factory.setMapper(objectMapper);
factory.setResources(new Resource[]{new ClassPathResource("badclassname.json"), new ClassPathResource("good.json"), new ClassPathResource("malformatted.json")});
return factory;
}
}
I've uploading a working example here
来源：https://stackoverflow.com/questions/60711819/spring-mongo-populator-one-by-one