mongodb实现多数据源

       最近在开发过程中遇到一个需求，想要实现该需求需要把一个mongodb库里面的表&数据复制到另一个mongodb库。首先需要做的一件事就是配置多数据源，由于项目采用SpringBoot，所以配置多数据源也是在这个框架基础上的。话不多说，直接上代码

首先pom.xml需要引入如下配置

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-configuration-processor</artifactId>
   <optional>true</optional>
</dependency>
<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>

分别定义三个类AbstractMongoConfig、PrimaryMongoConfig、SecondMongoConfig

import com.mongodb.MongoClientURI;
import org.springframework.data.mongodb.MongoDbFactory;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.SimpleMongoDbFactory;

/**
 * 描述
 *
 * @author mczhou2 2020/3/2010:50
 */
public abstract  class AbstractMongoConfig {
    //连接MongoDB地址
    private String uri;
    /**
     * 获取mongoDBTemplate对象
     */
    public abstract MongoTemplate getMongoTemplate() throws Exception;
    /**
     * 创建mongoDb工厂
     */
    public MongoDbFactory mongoDbFactory() throws Exception {
        MongoClientURI mongoclienturi = new MongoClientURI(uri);
        return new SimpleMongoDbFactory(mongoclienturi);
    }
    public String getUri() {
        return uri;
    }

    public void setUri(String uri) {
        this.uri = uri;
    }
}

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.data.mongodb.core.MongoTemplate;

/**
 * 描述
 *
 * @author mczhou2 2020/3/20 10:51
 */
@Configuration
@ConfigurationProperties(prefix = "spring.data.mongodb.primary")
public class PrimaryMongoConfig extends AbstractMongoConfig{
    @Override
    @Primary
    @Bean(name = "primaryMongoTemplate")
    public MongoTemplate getMongoTemplate() throws Exception {
        return new MongoTemplate((mongoDbFactory()));
    }
}

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.data.mongodb.core.MongoTemplate;

/**
 * 描述
 *
 * @author mczhou2 2020/3/2010:51
 */
@Configuration
@ConfigurationProperties(prefix = "spring.data.mongodb.second")
public class SecondaryMongoConfig extends AbstractMongoConfig{

    @Override
    @Primary
    @Bean(name = "secondMongoTemplate")
    public MongoTemplate getMongoTemplate() throws Exception {
        return new MongoTemplate((mongoDbFactory()));
    }
}

接下来启动类的注解需要屏蔽之前的类，否在项目启动报错

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.data.mongo.MongoDataAutoConfiguration;
import org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration;

@SpringBootApplication(exclude = {MongoAutoConfiguration.class, MongoDataAutoConfiguration.class})
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class,args);
    }
}

至此，mongodb多数据源就配置好了。这时候大家也许会问，前期准备工作好了，到底怎么用？你确定你想知道，那下回来我手把手教你。