Spring Boot 多个MongoDB 数据源配置与实现

迷南。 2021-12-14 17:43 610阅读 0赞

> ### 实现原理： ###

Spring Boot中通过依赖`spring-boot-starter-data-mongodb`，来实现`spring-data-mongodb`的自动配置，我们最终使用MongoDB操作数据库是通过 MongoTemplate类完成，他提供增删改查等方法

![20190904094227130.png][]

从上图可以看出MongoTemplate的连接配置可由MongoDbFactory 生成，从而提供了自定义连接的可能，

实际上，`spring-data-mongodb`的自动配置也是如此。

所以，可以创建多个一个MongoDbFactory 来构造不同的MongoTemplate，然后在操作数据库时根据使用场景注入不同的MongoTemplate来使用。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW4xMDc4NzY_size_16_color_FFFFFF_t_70][]

用数据库连接uri 创建 MongoClientURI ，再生成 SimpleMongoDbFactory，最后创建 **MongoTemplate即可。**

> ### 编码要点 ###

首先定义多个数据库的配置，代码对应下边第〇点

然后读取数据库的配置，代码对应下边第一点

读取对应的配置信息并且装配指定的MongoTemplate，第三点

所有文件：  
application.yml   
MultipleMongoProperties   
PrimaryMongoConfig  
SecondaryMongoConfig  
MultipleMongoConfig  
PersonTest  
MongoTestC

# 完整文件以及代码 #

## **〇、application.yml** **加上如下数据库配置** ##

mongodb:
      primary:
        host: 192.168.1.2
        port: 27017
        database: primary
        #username: admin
        #password: admin
    
      secondary:
        host: 192.168.1.3
        port: 27017
        database: secondary
        #username: admin
        #password: admin

**平时单个数据库配置格式为：spring:data:mongodb:... 是因为spring boot 默认的资源加载格式。这里mongodb开头是自定义。没有这个疑问的伙伴可以忽略这段话。。。**

## **一、配置数据库的数据源:** ##

**通过@ConfigurationProperties(prefix = "mongodb")读取配置文件的mongodb节点配置**

import org.springframework.boot.autoconfigure.mongo.MongoProperties;
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.stereotype.Component;
    
    /**
     * @ClassName: MultipleMongoProperties
     * @Description: 从配置文件加载数据源
     * @Author Tan
     * @Date 2019/7/3
     */
    @Component
    @ConfigurationProperties(prefix = "mongodb")
    public class MultipleMongoProperties {
    
        private MongoProperties primary = new MongoProperties();
        
        private MongoProperties secondary = new MongoProperties();
    
        public MongoProperties getPrimary() {
            return primary;
        }
    
        public void setPrimary(MongoProperties primary) {
            this.primary = primary;
        }
    
        public MongoProperties getSecondary() {
            return secondary;
        }
    
        public void setSecondary(MongoProperties secondary) {
            this.secondary = secondary;
        }
    }

## **二、两个数据库接口封装配置** ##

import org.springframework.context.annotation.Configuration;
    import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
    
    /**
     * @ClassName: PrimaryMongoConfig
     * @Description: TODO
     * @Author Tan
     * @Date 2019/7/3
     */
    @Configuration
    @EnableMongoRepositories(mongoTemplateRef = PrimaryMongoConfig.MONGO_TEMPLATE)
    public class PrimaryMongoConfig {
        public static final String MONGO_TEMPLATE = "primaryMongoTemplate";
    
    }

import org.springframework.context.annotation.Configuration;
    import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
    
    /**
     * @ClassName: PrimaryMongoConfig
     * @Description: TODO
     * @Author TanXiongZhan
     * @Date 2019/7/3
     */
    @Configuration
    @EnableMongoRepositories(mongoTemplateRef = SecondaryMongoConfig.MONGO_TEMPLATE)
    public class SecondaryMongoConfig {
        public static final String MONGO_TEMPLATE = "secondaryMongoTemplate";
    
    }

## **三、读取对应的配置信息并且装配对应的MongoTemplate(****关键的一步)** ##

import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Qualifier;
    import org.springframework.boot.autoconfigure.mongo.MongoProperties;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.Primary;
    import org.springframework.data.mongodb.MongoDbFactory;
    import org.springframework.data.mongodb.core.MongoTemplate;
    import org.springframework.data.mongodb.core.SimpleMongoDbFactory;
    
    /**
     * @ClassName: MultipleMongoConfig
     * @Description: 读取对应的配置信息并且构造对应的MongoTemplate
     * @Author Tan
     * @Date 2019/7/3
     */
    @Configuration
    public class MultipleMongoConfig {
    
        @Autowired
        private MultipleMongoProperties mongoProperties;
    
        @Primary
        @Bean(name = PrimaryMongoConfig.MONGO_TEMPLATE)
        public MongoTemplate primaryMongoTemplate() throws Exception {
            return new MongoTemplate(primaryFactory(this.mongoProperties.getPrimary()));
        }
    
        @Bean
        @Qualifier(SecondaryMongoConfig.MONGO_TEMPLATE)
        public MongoTemplate secondaryMongoTemplate() throws Exception {
            return new MongoTemplate(secondaryFactory(this.mongoProperties.getSecondary()));
        }
    
        @Bean
        @Primary
        public MongoDbFactory primaryFactory(MongoProperties mongo) throws Exception {
            if (StringUtils.isEmpty(mongo.getUsername()) || mongo.getPassword() == null ) {
                return new SimpleMongoDbFactory(new MongoClient(mongo.getHost(), mongo.getPort()),
                        mongo.getDatabase());
            } else {
                String password = String.valueOf(mongo.getPassword());
                String url = "mongodb://" + mongo.getUsername()
                        + ":" + password
                        + "@" + mongo.getHost() + ":" + mongo.getPort() + "/" + mongo.getDatabase()
                        + "?authSource=admin&authMechanism=SCRAM-SHA-1";
                return new SimpleMongoDbFactory(new MongoClientURI(url));
            }
        }
    
        @Bean
        public MongoDbFactory secondaryFactory(MongoProperties mongo) throws Exception {
            if (StringUtils.isEmpty(mongo.getUsername()) || mongo.getPassword() == null ) {
                        return new SimpleMongoDbFactory(new MongoClient(mongo.getHost(), mongo.getPort()),
                        mongo.getDatabase());
            } else {
                String password = String.valueOf(mongo.getPassword());
                String url = "mongodb://" + mongo.getUsername()
                        + ":" + password
                        + "@" + mongo.getHost() + ":" + mongo.getPort() + "/" + mongo.getDatabase()
                        + "?authSource=admin&authMechanism=SCRAM-SHA-1";
                return new SimpleMongoDbFactory(new MongoClientURI(url));
            }
        }
    
    }

**说明：@Primary 表明默认加载，假如使用的时候不表明具体的MongoTemplate，则使用@Primary所示的。如**

@Autowired 
    private MongoTemplate mongoTemplate;

** 则得到的 mongoTemplate 对象就是 primaryMongoTemplate**

## **四、使用** ##

### 1、定义实体对象 ###

public class PersonTest {
    
        private Integer id;
        private Integer age;
        private String name;
    
        public Integer getId() {
            return id;
        }
    
        public void setId(Integer id) {
            this.id = id;
        }
    
        public Integer getAge() {
            return age;
        }
    
        public void setAge(Integer age) {
            this.age = age;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
    }

### 2、测试与应用： ###

import org.springframework.data.mongodb.core.MongoTemplate;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import javax.annotation.Resource;
    
    
    @RestController
    @RequestMapping("mongoTest")
    public class MongoTestC {
    
        @Resource(name = PrimaryMongoConfig.MONGO_TEMPLATE)
        private MongoTemplate primaryMongoTemplate;     //第一个库的MongoTemplate
    
        @Resource(name = SecondaryMongoConfig.MONGO_TEMPLATE)
        private MongoTemplate secondaryMongoTemplate;   //第二个库的MongoTemplate
    
        @Autowired 
        private MongoTemplate mongoTemplate;            //第一个库的MongoTemplate
    
        @GetMapping(value = "/test1")
        public void saveTest() throws Exception {
            PersonTest mgtest = new PersonTest();
            mgtest.setId(8);
            mgtest.setAge(88);
            mgtest.setName("8888");
            primaryMongoTemplate.save(mgtest);
            secondaryMongoTemplate.save(mgtest);
        }
    }

[20190904094227130.png]: /images/20211214/17c30069c3bf459ebc92eb5c75ea6225.png
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