我们知道Spring Data MongoDB默认仅支持一个DataBase,而实际情况往往一个应用需要同时使用多个数据源。而此时我们需要自定义 MongoDB数据库连接。
MongoDB多数据源实现
抽象mongoDB配置 AbstractMongoConfig
普通配置
import com.mongodb.client.MongoClients;
import lombok.Getter;
import lombok.Setter;
import org.springframework.data.mongodb.MongoDbFactory;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.SimpleMongoClientDbFactory;
@Getter
@Setter
public abstract class AbstractMongoConfig {
//连接MongoDB地址
private String uri;
//数据库
private String dataBaseName;
/**
* 获取mongoDBTemplate对象
*/
public abstract MongoTemplate getMongoTemplate() throws Exception;
/**
* 创建mongoDb工厂
*/
public MongoDbFactory mongoDbFactory() throws Exception {
return new SimpleMongoClientDbFactory(MongoClients.create(uri), dataBaseName);
}
}
反应式 MongoDB 支持
import com.mongodb.reactivestreams.client.MongoClients;
import lombok.Getter;
import lombok.Setter;
import org.springframework.data.mongodb.ReactiveMongoDatabaseFactory;
import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
import org.springframework.data.mongodb.core.SimpleReactiveMongoDatabaseFactory;
@Setter
@Getter
public abstract class AbstractMongoConfigure {
//数据库连接
private String uri;
//数据库
private String dataBaseName;
public ReactiveMongoDatabaseFactory mongoDbFactory() throws Exception {
//使用uri创建数据库连接
SimpleReactiveMongoDatabaseFactory simpleMongoDbFactory
= new SimpleReactiveMongoDatabaseFactory(MongoClients.create(uri), dataBaseName);
return simpleMongoDbFactory;
}
abstract public ReactiveMongoTemplate getMongoTemplate() throws Exception;
}
继承AbstractMongoConfig 根据自定义配置获取多数据源MongoTemplate
普通模式
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
@Configuration
@EnableMongoRepositories(basePackages = {"com.xxxx.saas.xxx.infrastructure.mongo.umcservice"}, mongoTemplateRef = "umcMongoTemplate")
@RefreshScope
@ConfigurationProperties(prefix = "umc.spring.data.mongodb")
public class UmcServiceMongoConfig extends AbstractMongoConfig {
@Bean(name = "umcMongoTemplate")
@Override
public MongoTemplate getMongoTemplate() throws Exception {
return new MongoTemplate(mongoDbFactory());
}
}
反应式支持
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
import org.springframework.data.mongodb.repository.config.EnableReactiveMongoRepositories;
@Configuration
@EnableReactiveMongoRepositories
@RefreshScope
@ConfigurationProperties(prefix = "userevent.spring.data.mongodb")
public class UserEventMongoConfig extends AbstractMongoConfigure {
@Bean(name = "usereventMongoTemplate")
@Override
public ReactiveMongoTemplate getMongoTemplate() throws Exception {
return new ReactiveMongoTemplate(mongoDbFactory());
}
}
自此应用便可根据不同业务使用对应的MongoTemplate Bean对MongoDB进行操作。
MongoDB多数据源场景下使用存储库
我们知道Spring Data repository 抽象了为各种持久性存储实现数据访问层所需的样板代码量,使用MongoDB存储库大大简化了对MongoDB的访问。但是根据spring-data官方文档中的技术指引,默认创建存储库实例的方法并未提供多数据源的支持,因此无法常规配置指定自定义的数据源。
通过源码片段我们也可以看出存储库实例创建后,其数据源也无法正常修改。
public class SimpleMongoRepository<T, ID> implements MongoRepository<T, ID> {
private final MongoOperations mongoOperations;
private final MongoEntityInformation<T, ID> entityInformation;
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;
}
//省略
思路
基于AOP和反射机制,在存储库实例操作MongoDB之前动态修改存储库实例的mongoOperations以达到存储库支持多数据源的效果。
配置存储库
使用@EnableJpaRepositories("com.acme.repositories"),来触发存储库基础结构,并自定义数据源
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
@Configuration
@EnableMongoRepositories(basePackages = {"com.xxxx.saas.xxxxoperationserver.infrastructure.mongo.umcservice"}, mongoTemplateRef = "umcMongoTemplate")
@RefreshScope
@ConfigurationProperties(prefix = "umc.spring.data.mongodb")
public class UmcServiceMongoConfig extends AbstractMongoConfig {
@Bean(name = "umcMongoTemplate")
@Override
public MongoTemplate getMongoTemplate() throws Exception {
return new MongoTemplate(mongoDbFactory());
}
}
编写AOP
通过AOP操作,动态更改更改mongo的repository层mongoTemplate,实现MongoDB存储库分库。
import java.lang.reflect.Field;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.aop.framework.AopProxyUtils;
import org.springframework.aop.framework.ReflectiveMethodInvocation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.stereotype.Component;
import org.springframework.web.context.WebApplicationContext;
@Aspect
@Component
public class UmcRepositoryAop {
@Autowired
WebApplicationContext context;
@Around("execution(* com.xxxx.saas.xxxxoperationserver.infrastructure.mongo.umcservice..*.*(..))")
public Object setMongoOperations(ProceedingJoinPoint joinPoint) throws Throwable {
setMongoTemplate4Repository(joinPoint,
context.getBean("umcMongoTemplate", MongoTemplate.class));
return joinPoint.proceed();
}
private void setMongoTemplate4Repository(ProceedingJoinPoint joinPoint, MongoTemplate template)
throws NoSuchFieldException, IllegalAccessException {
// 通过反射获取到target
Field methodInvocationField = joinPoint.getClass().getDeclaredField("methodInvocation");
methodInvocationField.setAccessible(true);
ReflectiveMethodInvocation o = (ReflectiveMethodInvocation) methodInvocationField
.get(joinPoint);
Field targetField = o.getClass().getDeclaredField("target");
targetField.setAccessible(true);
Object target = targetField.get(o);
// 获得SimpleMongoRepository,并往里面填入指定mongoTemplate
Object singletonTarget = AopProxyUtils.getSingletonTarget(target);
Field mongoOperationsField = singletonTarget.getClass().getDeclaredField("mongoOperations");
mongoOperationsField.setAccessible(true);
mongoOperationsField.set(singletonTarget, template);
}
}
完成上述步骤,即完成存储库的分库操作。可以进行对应分库下的业务实现。
简单举例umc下的邮箱模板操作
定义邮箱模板Document
import lombok.Data;
import org.springframework.data.mongodb.core.index.Indexed;
import org.springframework.data.mongodb.core.mapping.Document;
import org.springframework.data.mongodb.core.mapping.Field;
@Data
@Document(collection="emailTemplate")
public class EmailTemplateDO {
@Field("_id")//主键,使用mongo内置主键,效率更高
private String id;
@Indexed(unique = true) //唯一索引
private String templateId;
private String template;
private String title;
private String locale;
}
定义邮箱模板存储库实例
这里继承分页存储库PagingAndSortingRepository
import com.xxxx.saas.xxxxoperationserver.infrastructure.mongo.umcservice.model.EmailTemplateDO;
import org.springframework.data.repository.PagingAndSortingRepository;
public interface EmailTemplateCrudRepository extends PagingAndSortingRepository<EmailTemplateDO, String> {
}
使用存储库操作MongoDB
@Component
public class EmailTemplateRepositoryImpl implements EmailTemplateRepository {
@Autowired
private EmailTemplateCrudRepository emailTemplateCrudRepository;
@Override
public PageResult<EmailTemplate> findAll(PageBean pageBean) {
Page<EmailTemplateDO> pageRet = emailTemplateCrudRepository.findAll(PageRequest.of(pageBean.getPage(), pageBean.getPagesize()));
List<EmailTemplateDO> modelList = pageRet.get().collect(Collectors.toList());
return PageResult.<EmailTemplate>builder()
.data(EmailTemplateDOAssembler.INSTANCE.toEntitys(modelList))
.code(200)
.count(Long.valueOf(pageRet.getTotalPages()))
.build();
}
}
经过单元测试,上述代码实现ok。