自定义 Spring 数据存储库 bean 名称以用于多个数据源

Question

我有一个项目利用 Spring 数据（在本例中为 MongoDB）与具有相同架构的多个数据库进行交互。这意味着每个数据库都使用相同的实体和存储库类。所以，例如：

public class Thing {
    private String id;
    private String name;
    private String type;
    // etc...  
}

public interface ThingRepository extends PagingAndSortingRepository<Thing, String> {
    List<Thing> findByName(String name);
}

@Configuration
@EnableMongoRepositories(basePackageClasses = { ThingRepository.class })
public MongoConfig extends AbstractMongoConfiguration {
    // Standard mongo config
}

如果我连接到单个数据库，这很好用，但是当我想同时连接到多个数据库时，事情就变得复杂了：

@Configuration
@EnableMongoRepositories(basePackageClasses = { ThingRepository.class },
    mongoTemplateRef = "mongoTemplateOne")
public MongoConfigOne extends AbstractMongoConfiguration {

    @Override
    @Bean(name = "mongoTemplateOne")
    public MongoTemplate mongoTemplate() throws Exception {
        return new MongoTemplate(this.mongo(), "db_one");
    }

    // Remaining standard mongo config

}

@Configuration
@EnableMongoRepositories(basePackageClasses = { ThingRepository.class },
    mongoTemplateRef = "mongoTemplateTwo")
public MongoConfigTwo extends AbstractMongoConfiguration {

    @Override
    @Bean(name = "mongoTemplateTwo")
    public MongoTemplate mongoTemplate() throws Exception {
        return new MongoTemplate(this.mongo(), "db_two");
    }

    // Remaining standard mongo config

}

我可以使用不同的 MongoTemplate 实例创建同一个存储库的多个实例，但我不知道引用和注入它们的正确方法。我希望能够将各个存储库实例注入不同的控制器，如下所示：

@Controller
@RequestMapping("/things/one/")
public class ThingOneController {
    @Resource private ThingRepository thingRepositoryOne;
    ...
}

@Controller
@RequestMapping("/things/two/")
public class ThingTwoController {
    @Resource private ThingRepository thingRepositoryTwo;
    ...
}

这样的配置可行吗？我能否以某种方式控制实例化接口的 bean 名称，以便我可以使用 @Resource 或 @Autowired 引用它们？

奖金问题：这也可以通过自定义存储库工厂来完成吗？

Answer 1

对于一般的 @Repository 你可以只添加 (value="someDao") 来命名创建的 Bean，如果 MongoRepository 扩展 Repository 这应该有效。

Answer 2

使用 @NoRepositoryBean 创建您的存储库接口，我们将自己连接它：

@NoRepositoryBean
public interface ModelMongoRepository extends MongoRepository<Model, String> {
}

然后，在 @Configuration class 中，使用 MongoRepositoryFactoryBean 实例化 2 个存储库 bean。两个存储库将 return 相同的 Spring Data Repository 接口，但我们将为它们分配不同的 MongoOperations（即：数据库详细信息）：

@Configuration
@EnableMongoRepositories
public class MongoConfiguration {

    @Bean
    @Qualifier("one")
    public ModelMongoRepository modelMongoRepositoryOne() throws DataAccessException, Exception {
        MongoRepositoryFactoryBean<ModelMongoRepository, Model, String> myFactory = new MongoRepositoryFactoryBean<ModelMongoRepository, Model, String>();
        myFactory.setRepositoryInterface(ModelMongoRepository.class);
        myFactory.setMongoOperations(createMongoOperations("hostname1", 21979, "dbName1", "username1", "password1"));
        myFactory.afterPropertiesSet();
        return myFactory.getObject();
    }

    @Bean
    @Qualifier("two")
    public ModelMongoRepository modelMongoRepositoryTwo() throws DataAccessException, Exception {
        MongoRepositoryFactoryBean<ModelMongoRepository, Model, String> myFactory = new MongoRepositoryFactoryBean<ModelMongoRepository, Model, String>();
        myFactory.setRepositoryInterface(ModelMongoRepository.class);
        myFactory.setMongoOperations(createMongoOperations("hostname2", 21990, "dbName2", "username2", "password2"));
        myFactory.afterPropertiesSet();
        return myFactory.getObject();
    }

    private MongoOperations createMongoOperations(String hostname, int port, String dbName, String user, String pwd) throws DataAccessException, Exception {
        MongoCredential mongoCredentials = MongoCredential.createScramSha1Credential(user, dbName, pwd.toCharArray());
        MongoClient mongoClient = new MongoClient(new ServerAddress(hostname, port), Arrays.asList(mongoCredentials));
        Mongo mongo = new SimpleMongoDbFactory(mongoClient, dbName).getDb().getMongo();
        return new MongoTemplate(mongo, dbName);
    }
    //or this one if you have a connection string
    private MongoOperations createMongoOperations(String dbConnection) throws DataAccessException, Exception {
        MongoClientURI mongoClientURI = new MongoClientURI(dbConnection);
        MongoClient mongoClient = new MongoClient(mongoClientURI);
        Mongo mongo = new SimpleMongoDbFactory(mongoClient, mongoClientURI.getDatabase()).getDb().getMongo();
        return new MongoTemplate(mongo, mongoClientURI.getDatabase());
    }
}

您现在有 2 个具有不同 @Qualifier 名称的 bean，每个 bean 配置为不同的数据库，并使用相同的模型。

您可以使用 @Qualifier 注入它们：

@Autowired
@Qualifier("one")
private ModelMongoRepository mongoRepositoryOne;

@Autowired
@Qualifier("two")
private ModelMongoRepository mongoRepositoryTwo;

为简单起见，我在配置 class 中对值进行了硬编码，但您可以从应用程序的属性中注入它们。properties/yml。

EDIT to answer comments:

如果您想在不失去 spring 数据接口存储库的优势的情况下创建自定义实现，请进行修改。规格是这样说的：

Often it is necessary to provide a custom implementation for a few repository methods. Spring Data repositories easily allow you to provide custom repository code and integrate it with generic CRUD abstraction and query method functionality. To enrich a repository with custom functionality you first define an interface and an implementation for the custom functionality. Use the repository interface you provided to extend the custom interface. The most important bit for the class to be found is the Impl postfix of the name on it compared to the core repository interface (see below).

创建一个新界面，技术上与spring数据无关，老界面不错：

public interface CustomMethodsRepository {
    public void getById(Model model){
}

让您的存储库接口扩展这个新接口：

@NoRepositoryBean
public interface ModelMongoRepository extends MongoRepository<Model, String>, CustomMethodsRepository {
}

然后，创建您的实现 class，它仅实现您的非 spring 数据接口：

public class ModelMongoRepositoryImpl  implements CustomModelMongoRepository {
    private MongoOperations mongoOperations;

    public ModelMongoRepositoryImpl(MongoOperations mongoOperations) {
        this.mongoOperations = mongoOperations;
    }
    public void getById(Model model){
        System.out.println("test");
    }
}

更改 Java 配置以添加 myFactory.setCustomImplementation(new ModelMongoRepositoryImpl()); :

@Bean
@Qualifier("one")
public ModelMongoRepository modelMongoRepositoryOne() throws DataAccessException, Exception {
    MongoRepositoryFactoryBean<ModelMongoRepository, Model, String> myFactory = new MongoRepositoryFactoryBean<ModelMongoRepository, Model, String>();
    MongoOperations mongoOperations = createMongoOperations("hostname1", 21979, "dbName1", "usdername1", "password1");
    myFactory.setCustomImplementation(new ModelMongoRepositoryImpl(mongoOperations));
    myFactory.setRepositoryInterface(ModelMongoRepository.class);
    myFactory.setMongoOperations(mongoOperations);

    myFactory.afterPropertiesSet();
    return myFactory.getObject();
}

如果您没有通过 Java 配置手动连接存储库，则此实现必须命名为 ModelMongoRepositoryImpl 以匹配接口 ModelMongoRepository +"Impl"。它将由 spring.

自动处理

自定义 Spring 数据存储库 bean 名称以用于多个数据源

Customizing Spring Data repository bean names for use with multiple data sources

java

spring

mongodb

spring-data

spring-data-mongodb