JPA+Mongodb多数据源配置

Tags: /Java/ Date Created:

如何配置SpringBoot下的Mongodb多数据源呢？

1. 配置 application 属性

例如 yml 配置，配置多个数据源，如下面：

spring:
  data:
    db1:
      user: <username>
      password: <password>
      hosts: www.abc.com
      database: demo1
      options: authSource=admin&maxPoolSize=10&minPoolSize=2&connectTimeoutMS=600000&socketTimeoutMS=600000&authMechanism=SCRAM-SHA-256&tls=true
    db2:
      user: <username>
      password: <password>
      hosts: www.abc.com
      database: demo1
      options: authSource=admin&maxPoolSize=10&minPoolSize=2&connectTimeoutMS=600000&socketTimeoutMS=600000&authMechanism=SCRAM-SHA-256&tls=true
    db3:
      user: <username>
      password: <password>
      hosts: www.abc.com
      database: demo1
      options: authSource=admin&maxPoolSize=10&minPoolSize=2&connectTimeoutMS=600000&socketTimeoutMS=600000&authMechanism=SCRAM-SHA-256&tls=true

2. 创建Spring Config配置

例如在项目源代码的 config 目录下，新建三个配置 java 代码文件：

MongoConfiguration.java是主要的配置文件，里面指明了Spring注入时组件用哪个bean，且对应bean用哪个数据源。

MongoConfiguration.java:

import com.mongodb.client.MongoClients;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.data.mongodb.MongoDatabaseFactory;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.SimpleMongoClientDatabaseFactory;

@Configuration
public class MongoConfiguration {
  public static final String MONGODB_URI = "mongodb://%s:%s@%s/%s?%s";
  @Value("${spring.data.db1.username}")
  private String user;
  @Value("${spring.data.db1.password}")
  private String password;
  @Value("${spring.data.db1.hosts}")
  private String hosts;
  @Value("${spring.data.db1.database}")
  private String database;
  @Value("${spring.data.mongodb.options:authSource=admin&tls=true&maxPoolSize=10&minPoolSize=2&connectTimeoutMS=60000&socketTimeoutMS=60000}")
  private String options;

  @Value("${spring.data.db2.username}")
  private String user2;
  @Value("${spring.data.db2.password}")
  private String password2;
  @Value("${spring.data.db2.hosts}")
  private String hosts2;
  @Value("${spring.data.db2.database}")
  private String db2;
  @Value("${spring.data.db2.options:authSource=admin&tls=true&maxPoolSize=10&minPoolSize=2&connectTimeoutMS=60000&socketTimeoutMS=60000}")
  private String options3;

  @Value("${spring.data.db3.username}")
  private String user3;
  @Value("${spring.data.db3.password}")
  private String password3;
  @Value("${spring.data.db3.hosts}")
  private String hosts3;
  @Value("${spring.data.db3.database}")
  private String db3;
  @Value("${spring.data.db3.options:authSource=admin&tls=true&maxPoolSize=10&minPoolSize=2&connectTimeoutMS=60000&socketTimeoutMS=60000}")
  private String options3;

  @Primary
  @Bean(name = PrimaryMongoConfig.MONGO_TEMPLATE)
  public MongoTemplate primaryMongoTemplate() {
    return new MongoTemplate(primaryFactory());
  }

  @Bean
  @Qualifier(SecondaryMongoConfig.MONGO_TEMPLATE)
  public MongoTemplate secondaryMongoTemplate() {
    return new MongoTemplate(secondaryFactory());
  }

  @Bean
  @Qualifier(ThirdConfig.MONGO_TEMPLATE)
  public MongoTemplate thirdMongTempate() {
    return new MongoTemplate(thirdFactory());
  }

  @Bean
  public MongoDatabaseFactory thirdFactory() {
    String uri = String.format(MONGODB_URI, user3, escape(password3), hosts3, database3, options3);
    return new SimpleMongoClientDatabaseFactory(MongoClients.create(uri), database3);
  }

  @Bean
  @Primary
  public MongoDatabaseFactory primaryFactory() {
    String uri = String.format(MONGODB_URI, user, escape(password), hosts, database, options);
    return new SimpleMongoClientDatabaseFactory(MongoClients.create(uri), database);
  }

  @Bean
  public MongoDatabaseFactory secondaryFactory() {
    String uri = String.format(MONGODB_URI, user2, escape(password2), hosts2, database2, options2);
    return new SimpleMongoClientDatabaseFactory(MongoClients.create(uri), database2);
  }

  /**
   * Escape special char of password for MongoDB connection string
   *
   * @param password Raw password string, might from ENV variable
   * @return escaped password
   */
  private String escape(String password) {
    return password.replace("@", "%40")
        .replace("/", "%2F")
        .replace("?", "%3F")
        .replace("[", "%5B")
        .replace("]", "%5D")
        .replace(",", "%2C")
        .replace("#", "%23");
  }
}

新建 PrimaryMongoConfig.java:

import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;

@Configuration
@EnableMongoRepositories(basePackages = "com.abc.xyz.db1",
    mongoTemplateRef = PrimaryMongoConfig.MONGO_TEMPLATE)
public class PrimaryMongoConfig {
  protected static final String MONGO_TEMPLATE = "primaryMongoTemplate";
}

新建SecondaryMongoConfig.java：

import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;

@Configuration
@EnableMongoRepositories(basePackages = "com.abc.xyz.db2",
    mongoTemplateRef = PrimaryMongoConfig.MONGO_TEMPLATE)
public class SecondaryMongoConfig {
  protected static final String MONGO_TEMPLATE = "secondaryMongoTemplate";
}

新建 ThirdMongoConfig.java：

import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;

@Configuration
@EnableMongoRepositories(basePackages = "com.abc.xyz.db3",
    mongoTemplateRef = PrimaryMongoConfig.MONGO_TEMPLATE)
public class ThirdMongoConfig {
  protected static final String MONGO_TEMPLATE = "thirdMongoTemplate";
}

当然你也可以把上面第一个java文件分散到 Primary, Secondary, Third中去，这样只要三个文件，更清晰明了一些。

3. 创建包目录和Repository

在程序源码目录下，新建对应的 com.abc.xyz.db1, com.abc.xyz.db2, com.abc.xyz.db3 等三个包目录，然后把对应数据库的 Repository 的定义放到对应的目录下。

例如：

import com.abc.xyz.Order;
import org.springframework.data.mongodb.repository.MongoRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface OrderRepository extends MongoRepository<Order, String> {
}

4. 使用

使用时按正常的方式 @Autowired 即可，对于 Template这个公共对象，我们需要以修饰词限定即可。

例如：

  @Autowired
  private OrderRepository orderRepository;
 
  @Autowired
  @Qualifier(SecondaryMongoConfig.MONGO_TEMPLATE)
  private MongoTemplate template2;