java - 如何在spring-boot中使用具有多个数据库的Mongodb单实例

Question

我有一种情况，我有多个客户端连接到我的应用程序，我想在同一个 Mongo 服务器中为每个客户端提供自己的“模式/数据库”。

我的配置类:

@Configuration
public class MongoDbConfiguration {

@Bean
@Primary
public MongoDbFactory mongoDbFactory() throws UnknownHostException {
    return new MultiTenantMongoDbFactory();
}

@Bean
@Primary
public MongoTemplate mongoTemplate() throws UnknownHostException {
    return new MongoTemplate(mongoDbFactory());
}
}

Multi-Tenancy 数据库工厂

public class MultiTenantMongoDbFactory extends SimpleMongoDbFactory {

public MultiTenantMongoDbFactory() throws UnknownHostException {
    super(getMongoClient(), TenantContext.getTenant());
}

@Override
public DB getDb() throws DataAccessException {
    String tenant = TenantContext.getTenant();
    return getDb(tenant);

}

private static MongoClient getMongoClient() {
    String tenant = TenantContext.getTenant();
    System.out.println("Database name in factory class :"+tenant);
    if (tenant.equalsIgnoreCase("ncet")) {
        MongoCredential mongoCredential = MongoCredential.createCredential("user1", "db1",
                "pwd1".toCharArray());
        ServerAddress serverAddress = new ServerAddress("localhost", 27017);
        MongoClient mongoClient = new MongoClient(serverAddress, Arrays.asList(mongoCredential));
        return mongoClient;
    }else{
        MongoCredential mongoCredential = MongoCredential.createCredential("user1", "db2",
                "pwd2".toCharArray());
        ServerAddress serverAddress = new ServerAddress("localhost", 27017);
        MongoClient mongoClient = new MongoClient(serverAddress, Arrays.asList(mongoCredential));
        return mongoClient;
    }

}

每个数据库都有凭据

Answer 1

您的示例不起作用，因为 getMongoClient() 在启动期间仅调用一次，但您需要在运行时根据 Activity 租户进行更改。以 spring SimpleMongoDbFactory 为例，为 Multi-Tenancy 实现专用的 MongoDbFactory 非常简单。如果需要，您可以为其添加更多逻辑(对于 writeConcern 等)。此样本中有两个租户(东部和西部)。每个租户都有自己的 MongoClient，并在 MongoConfig 中配置相应的数据库名称和凭据。 TenantDataFactory 根据TenantContext 中的当前Tenant 返回租户相关信息。 DB 对象是使用 MongoClient 和 TenantData 中的数据库名称创建的，由 TenantDataFactory 返回。

public class MultiTenantMongoDbFactory implements MongoDbFactory {

  private PersistenceExceptionTranslator exceptionTranslator;
  private TenantDataFactory tenantDataFactory;

  public MultiTenantMongoDbFactory(TenantDataFactory tenantDataFactory) {
    this.exceptionTranslator = new MongoExceptionTranslator();
    this.tenantDataFactory = tenantDataFactory;
  }

  @Override
  public DB getDb(String dbName) throws DataAccessException {
    return getDb();
  }

  @Override
  public DB getDb() throws DataAccessException {
    Tenant tenant = TenantContext.getCurrentTenant();
    TenantData tenantData = tenantDataFactory.getTenantData(tenant);
    return MongoDbUtils.getDB(tenantData.getClient(), tenantData.getDbName());
  }

  @Override
  public PersistenceExceptionTranslator getExceptionTranslator() {
    return exceptionTranslator;
  }
}

public class TenantDataFactory {

  private Map<Tenant, TenantData> tenantDataMap;

  public TenantDataFactory(Map<Tenant, TenantData> tenantDataMap) {
    this.tenantDataMap = Collections.unmodifiableMap(tenantDataMap);
  }

  public TenantData getTenantData(Tenant tenant) {
    TenantData tenantData = tenantDataMap.get(tenant);
    if (tenantData == null) {
      // or return default tenant
      throw new IllegalArgumentException("Unsupported tenant " + tenant);
    }
    return tenantData;
  }
}

public enum Tenant {
  EAST, WEST
}

public class TenantData {

  private final String dbName;
  private final MongoClient client;

  public TenantData(String dbName, MongoClient client) {
    this.dbName = dbName;
    this.client = client;
  }

  public String getDbName() {
    return dbName;
  }

  public MongoClient getClient() {
    return client;
  }
}

public class TenantContext {

  private static ThreadLocal<Tenant> currentTenant = new ThreadLocal<>();

  public static void setCurrentTenant(Tenant tenant) {
    currentTenant.set(tenant);
  }

  public static Tenant getCurrentTenant() {
    return currentTenant.get();
  }
}

@Configuration
public class MongoConfig {

  @Bean(name = "eastMongoClient", destroyMethod = "close")
  public MongoClient eastMongoClient() {
    return new MongoClient(new ServerAddress("127.0.0.1", 27017),
        Collections.singletonList(MongoCredential.createCredential("user1", "east", "password1".toCharArray())));
  }

  @Bean(name = "westMongoClient", destroyMethod = "close")
  public MongoClient westMongoClient() {
    return new MongoClient(new ServerAddress("127.0.0.1", 27017),
        Collections.singletonList(MongoCredential.createCredential("user2", "west", "password2".toCharArray())));
  }

  @Bean
  public TenantDataFactory tenantDataFactory(@Qualifier("eastMongoClient") MongoClient eastMongoClient,
                                             @Qualifier("westMongoClient") MongoClient westMongoClient) {
    Map<Tenant, TenantData> tenantDataMap = new HashMap<>();
    tenantDataMap.put(Tenant.EAST, new TenantData("east", eastMongoClient));
    tenantDataMap.put(Tenant.WEST, new TenantData("west", westMongoClient));
    return new TenantDataFactory(tenantDataMap);
  }

  @Bean
  public MongoDbFactory mongoDbFactory(@Autowired TenantDataFactory tenantDataFactory) {
    return new MultiTenantMongoDbFactory(tenantDataFactory);
  }

  @Bean
  public MongoTemplate mongoTemplate(@Autowired MongoDbFactory mongoDbFactory) {
    return new MongoTemplate(mongoDbFactory);
  }
}