Mongodb 的 Spring Boot 和数据库默认数据

Question

I have a Spring Boot project that use Mongodb. So, in my pom i have that dependence:

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>

So i'm able to access to the database with this repository class:

package it.de.marini.server.dal;

import org.springframework.data.mongodb.repository.MongoRepository;

import it.de.marini.server.model.Role;

public interface RoleRepository extends MongoRepository<Role, String> {

}

I need to inizialize my data in Mongodb database putting default Role for example. What is the best way in Spring Boot framework?

Answer 1

There are several ways to do this, I will suggest you with CommandlineRunner

try:

@Bean
public CommandLineRunner initConfig(MyRepo repo) {
  if (data not exist) {
      repo.save(...);
  }

}

Otherwise you can use @PostConstruct to initiate it..

if you need something like liquibase for RDBMS, checkout mongobee: https://github.com/mongobee/mongobee

Answer 2

As @Jaiwo99 say i understand that there is not a standard for do that. So i decided to make the work with Spring Batch. I realized a batch for load from CSV files Roles and Permissions of my application.

@Configuration
@EnableBatchProcessing
public class BatchConfiguration {

@Autowired
public JobBuilderFactory jobBuilderFactory;

@Autowired
public StepBuilderFactory stepBuilderFactory;

@Autowired
public MongoTemplate mongoTemplate;

@Bean
public PlatformTransactionManager transactionManager() {
    return new ResourcelessTransactionManager();
}

@Bean
public Tasklet defaultRolePermissionTasklet() {
    return new DefaultRolePermissionTasklet();
}


public <T> FlatFileItemReader<T> readerFile(String fileName,String[] fields,Class<T> type)  {

    FlatFileItemReader<T> reader = new FlatFileItemReader<T>();
    reader.setStrict(false);
    reader.setResource(new ClassPathResource(fileName));
    reader.setLineMapper(new DefaultLineMapper<T>() {
        {
            setLineTokenizer(new DelimitedLineTokenizer() {
                {
                    setNames(fields);
                    setStrict(false);
                }
            });
            setFieldSetMapper(new BeanWrapperFieldSetMapper<T>() {
                {
                    setTargetType(type);
                }
            });
        }
    });
    return reader;

}

@Bean
public PermissionItemProcessor permissionProcessor() {
    return new PermissionItemProcessor();
}

@Bean
public RoleItemProcessor roleProcessor() {
    return new RoleItemProcessor();
}

@Bean
public Job initAuthenticationData(JobCompletionNotificationListener listener) {
    return jobBuilderFactory.get("initAuthenticationData").incrementer(new RunIdIncrementer()).listener(listener)
            .start(stepPermission())
            .next(stepRole())
            .next(stepDefaultRolePermissions())
            .build();
}

@Bean
public Step stepDefaultRolePermissions() {
    return stepBuilderFactory.get("stepDefaultRolePermissions").tasklet(defaultRolePermissionTasklet()).build();
}


@Bean
public Step stepPermission() {

    MongoItemWriter<Permission> writer = new MongoItemWriter<Permission>();
    writer.setTemplate(mongoTemplate);




    return stepBuilderFactory.get("stepPermission").<Permission, Permission>chunk(20)
            .reader(readerFile("permission-data.csv",new String[] {"name","description"},Permission.class))
            .processor(permissionProcessor())
            .writer(writer)
            .build();
}

@Bean
public Step stepRole() {
    MongoItemWriter<Role> writer = new MongoItemWriter<Role>();
    writer.setTemplate(mongoTemplate);

    return stepBuilderFactory.get("stepRole").<Role, Role>chunk(20)
            .reader(readerFile("role-data.csv",new String[] {"name","description"},Role.class))
            .processor(roleProcessor())
            .writer(writer)
            .build();
    }
}

Answer 3

At least, there is one more way how to initialize data in Mongodb using Spring Boot. You can create in your configuration like this:

@Configuration
public class AppConfiguration {

    @Autowired
    public void prepare(ReactiveMongoOperations mongoOperations,
                        UserRepository userRepository) {
        mongoOperations.createCollection("users",
                CollectionOptions.empty()
                        .maxDocuments(1_000)
                        .size(1024 * 8)
                        .capped()).block();
        userRepository
                .insert(List.of(
                        User.builder()
                                .name("Joe Doe")
                                .build()
                ))
                .blockLast();
    }
}

And of course, you must make a check that collection doesn't exist, in order to not create a collection if the database has already been created.