# dynamic-mongo-spring-boot-starter

**Repository Path**: anonuser/dynamic-mongo-spring-boot-starter

## Basic Information

- **Project Name**: dynamic-mongo-spring-boot-starter
- **Description**: mongo多数据源
- **Primary Language**: Java
- **License**: Apache-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 1
- **Created**: 2025-02-07
- **Last Updated**: 2025-02-07

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

#### 1，增加dynamic-mongo-spring-boot-starter的pom引用

```xml
<dependency>
    <groupId>com.wuuxiang</groupId>
    <artifactId>dynamic-mongo-spring-boot-starter</artifactId>
    <version>0.0.1</version>
</dependency>
```

#### 2,yml文件里面增加mongo多数据源的配置

```yaml
spring:
  data:
    mongodb:
      dynamic:
        primary: i5x
        remove-under-class: true
        datasource:
          i5x:
            uri: mongodb://username:password@ip:port/i5xdatabase?replicaSet=repl&authSource=i5xauthdatabase&readPreference=secondaryPreferred
          fans:
            uri: mongodb://username:password@ip:port/fansdatabase?replicaSet=repl&authSource=fansauthdatabase&readPreference=secondaryPreferred
```

#### 3,代码的类上，或者方法上面使用@MongoDS("xxx")来指定数据源，不指定的话，默认走primary数据源

```java
//类上面
@MongoDS("i5x")
@Service
public class WaiMaiShopServiceImpl extends BaseServiceImpl implements WaiMaiShopService {
    // 每组最大数量
    private static final Integer MAX_GROUP_SIZE = 200;
    @Autowired
    private LbsQqUtil lbsQqUtil;
    @Autowired
    private RedisTemplate<String, Double> redisTemplate;
    @Autowired
    private DeliveryMobileSchemeRepository deliveryMobileSchemeRepository;
}
```

```
//方法上面
@MongoDS("fans")
@Override
public PhoDeliveryInstall getPhoDeliveryInstallByMcId(Object zoneShardingKey,Integer gcId,Integer mcId,Integer deliveryInstallType){
        List<PhoDeliveryInstall> phoDeliveryInstalls=getPhoDeliveryInstall(zoneShardingKey,gcId,Lists.newArrayList(mcId),deliveryInstallType);
        if(CollectionUtils.isEmpty(phoDeliveryInstalls)){
          return null;
        }
        return phoDeliveryInstalls.get(0);
}
```

#### 4,约定

- 本框架只做 切换数据源 这件核心的事情，并不限制你的具体操作，切换了数据源可以做任何CRUD。
- 方法上的注解优先于类上注解。
- MongoDS支持继承抽象类上的MongoDS，暂不支持继承接口上的MongoDS。

#### 5,原理

spring内有两种操作mongo的方式
1,MongoTemplate
2,MongoRepository

MongoTemplate的方式：

在MongoDatabaseFactoryDependentConfiguration中可以看到，MongoTemplate内部注入了一个MongoDatabaseFactory

```
@Bean
@ConditionalOnMissingBean(MongoOperations.class)
MongoTemplate mongoTemplate(MongoDatabaseFactory factory, MongoConverter converter) {
    return new MongoTemplate(factory, converter);
}
```

在MongoDatabaseFactoryConfiguration中可以看到，MongoDatabaseFactory为SimpleMongoClientDatabaseFactory实例

```
@Bean
MongoDatabaseFactorySupport<?> mongoDatabaseFactory(MongoClient mongoClient, MongoProperties properties) {
    return new SimpleMongoClientDatabaseFactory(mongoClient, properties.getMongoClientDatabase());
}
```

然后后续的MongoDatabase连接都是由SimpleMongoClientDatabaseFactory来维护。

所以我们的思路很简单，自定义一个DynamicMongoDatabaseFactory，内部维护一个Map<String,SimpleMongoClientDatabaseFactory>来切换多数据源。

Main-->MongoTemplate-->DynamicMongoDatabaseFactory-->根据@MongoDS注解的value从Map中取出对应SimpleMongoClientDatabaseFactory-->操作CRUD Mongo库

MongoRepository的方式：

MongoRepository的实现类为SimpleMongoRepository，可以看到其内部注入了MongoOperations

```
public SimpleMongoRepository(MongoEntityInformation<T, ID> metadata, MongoOperations mongoOperations) {
    Assert.notNull(metadata, "MongoEntityInformation must not be null!");
    Assert.notNull(mongoOperations, "MongoOperations must not be null!");
    this.entityInformation = metadata;
    this.mongoOperations = mongoOperations;
}
```

而MongoTemplate正是MongoOperations的实现类，所以其实MongoRepository也是通过MongoTemplate来操作Mongo库的。