Springboot集成MongoDb多数据源(五)

忘是亡心i 2022-03-01 12:28 675阅读 0赞

[上一章][Link 1]已经介绍了MongoDb介绍以及集成，现在进行MongoDb多数据源的讲解。

--------------------

**1、pom包配置**

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-autoconfigure</artifactId>
        <version>RELEASE</version>
    </dependency>

--------------------

**2、配置文件application.properties形式添加两条数据源，如下**

> **mongodb.first.host** = **127.0.0.1**  
> **mongodb.first.port** = **27017**  
> **mongodb.first.database** = **multi1**  
> **mongodb.second.host** = **127.0.0.1**  
> **mongodb.second.port** = **27017**  
> **mongodb.second.database** = **multi2**

--------------------

**3、配置两个库的数据源**

>   **3.1** 封装读取以mongodb开头的两个配置文件，注意此@ConfigurationProperties对应的mongodb与数据源中对应。
> 
>      prefix = "mongodb ：加载配置文件分隔符
> 
>      new MongoProperties()：直接加载配置文件类

@ConfigurationProperties(prefix = "mongodb")
    public class MultipleMongoProperties {
    
        private MongoProperties first = new MongoProperties();
        private MongoProperties second = new MongoProperties();
    
        public MongoProperties getFirst() {
            return first;
        }
    
        public void setFirst(MongoProperties first) {
            this.first = first;
        }
    
        public MongoProperties getSecond() {
            return second;
        }
    
        public void setSecond(MongoProperties second) {
            this.second = second;
        }
    }

> **3.2** 配置不同包路径下使用不同的数据源

**第一个库的封装**

@Configuration
    @EnableMongoRepositories(basePackages = "com.example.multipledsmongodb.model.first",
            mongoTemplateRef = FirstMongoConfig.MONGO_TEMPLATE)
    public class FirstMongoConfig {
        protected static final String MONGO_TEMPLATE = "firstMongoTemplate";
    }

**第二个库的封装**

@Configuration
    @EnableMongoRepositories(basePackages = "com.example.multipledsmongodb.model.second",
            mongoTemplateRef = SencondMongoConfig.MONGO_TEMPLATE)
    public class SencondMongoConfig {
        protected static final String MONGO_TEMPLATE = "sencondMongoTemplate";
    }

> **3.3** 读取对应的配置信息并且构造对应的MongoTemplate

@Configuration
    public class MultipleMongoConfig {
        @Autowired
        private MultipleMongoProperties mongoProperties;
    
        @Primary
        @Bean(name = FirstMongoConfig.MONGO_TEMPLATE)
        public MongoTemplate firstMongoTemplate() throws Exception {
            return new MongoTemplate(primaryFactory(this.mongoProperties.getFirst()));
        }
    
        @Bean
        @Qualifier(SencondMongoConfig.MONGO_TEMPLATE)
        public MongoTemplate sencondMongoTemplate() throws Exception {
            return new MongoTemplate(secondaryFactory(this.mongoProperties.getSecond()));
        }
    
        @Bean
        @Primary
        public MongoDbFactory primaryFactory(MongoProperties mongo) throws Exception {
            return new SimpleMongoDbFactory(new MongoClient(mongo.getHost(), mongo.getPort()),
                    mongo.getDatabase());
        }
    
        @Bean
        public MongoDbFactory secondaryFactory(MongoProperties mongo) throws Exception {
            return new SimpleMongoDbFactory(new MongoClient(mongo.getHost(), mongo.getPort()),
                    mongo.getDatabase());
        }
    }

两个库的配置信息已经完成。

--------------------

**4、创建两个库分别对应的对象和Repository**

@Document(collection = "first_obj")
    public class FirstObj {
        @Id
        private String id;
    
        private String value;
    
        public String getId() {
            return id;
        }
    
        public void setId(String id) {
            this.id = id;
        }
    
        public String getValue() {
            return value;
        }
    
        public void setValue(String value) {
            this.value = value;
        }
    
        public FirstObj(String id, String value) {
            this.id = id;
            this.value = value;
        }
    
        @Override
        public String toString() {
            return "FirstObj{" +
                    "id='" + id + '\'' +
                    ", value='" + value + '\'' +
                    '}';
        }
    }

> 对应的Repository

public interface FirstRepository extends MongoRepository<FirstObj, String> {
    }

> 继承了 MongoRepository 会默认实现很多基本的增删改查，省了很多自己写dao层的代码。
> 
> Second和上面的代码类似就不贴出来了

--------------------

**5、最后测试**

@RunWith(SpringRunner.class)
    @SpringBootTest
    public class MultipleDataSourceTest {
        @Autowired
        private FirstRepository firstRepository;
        @Autowired
        private SecondRepository secondRepository;
    
        @Test
        public void save() {
            this.firstRepository
                    .save(new FirstObj(null, "第一个库的对象"));
    
            this.secondRepository
                    .save(new SecondObj(null, "第二个库的对象"));
    
            List<FirstObj> primaries = this.firstRepository.findAll();
            for (FirstObj primary : primaries) {
                System.out.println(primary.toString());
            }
    
            List<SecondObj> secondaries = this.secondRepository.findAll();
    
            for (SecondObj secondary : secondaries) {
                System.out.println(secondary.toString());
            }
        }
    }

> 执行@Test注解的方法后

![2019032216574738.png][]

> 打开Robo 3T查看信息如下：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1Zm9yZXZlcmxvdmU_size_16_color_FFFFFF_t_70][]

多数据源就此完毕，谢谢！

--------------------

**6、遇到的问题**

** 6.1** 报Consider defining a bean of type com.xxRepository'in your configuration

原因：发现在启动类中缺少注解@EnableTransactionManagement

**6.2 ** ....nested exception is java.lang.NullPointerException

可能原因：在新建的MultipleMongoProperties里，@ConfigurationProperties(prefix = "mongodb")的注解的mongodb要和数据源配置一致，并且new的对像的引用也要保持一致。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1Zm9yZXZlcmxvdmU_size_16_color_FFFFFF_t_70 1][]

**7、最后**

参考文档：[https://blog.csdn.net/a123demi/article/details/78239251][https_blog.csdn.net_a123demi_article_details_78239251]

demo地址：[https://github.com/xuhuaguang/multipleds-mongodb.git][https_github.com_xuhuaguang_multipleds-mongodb.git]

[Link 1]: https://blog.csdn.net/xuforeverlove/article/details/88712561
[2019032216574738.png]: /images/20220301/f2d5fb2ab7804eedb49ef7cbcbb100ee.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1Zm9yZXZlcmxvdmU_size_16_color_FFFFFF_t_70]: /images/20220301/50ece9a713ea4368a597a4d847e21430.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1Zm9yZXZlcmxvdmU_size_16_color_FFFFFF_t_70 1]: /images/20220301/24cc30772eac4c87a151da70b7721e83.png
[https_blog.csdn.net_a123demi_article_details_78239251]: https://blog.csdn.net/a123demi/article/details/78239251
[https_github.com_xuhuaguang_multipleds-mongodb.git]: https://github.com/xuhuaguang/multipleds-mongodb.git