How to configure neo4j and cassandra repositories in same spring boot application

问题

I have configured neo4j and cassandra repositories separately with spring boot using spring-data. However, when I try to use two repositories in the same projects it doesn't work as expected.

This is my folder structure.

-----org.test.project

 -----controller
      BarController
      FooController
 -----models
      -----dao
           -----cassandra
                BarDAO
                FooDAO
           -----neo4j
                BarDAO
                FooDAO
 -----repositories
      -----cassandra
           BarRepository
           FooRepository
      -----neo
           BarRepository 
           FooRepository
 -----services
      CassandraService (Has cassandra repositories @Autowired)
      NeoService(Has neo repositories @Autowired)
 TestApp.java

Note that all the repositories extend respective spring-datarepository with respective DAO.

When I run with this configurations it gives the following error.

 Field airportRepository in org.test.project.TestApp required a bean of type 'org.test.project.repositories.cassandra.BarRepository' that could not be found.

I tried changing the Repository names. Then it started to work.

First question is can't we have same names as they are in different packages and start working

Though it started to work this time it gave an error in the authentication header.

 org.neo4j.ogm.drivers.http.request.HttpRequestException: http://localhost:7474/db/data/transaction/commit: No authentication header supplied.

I have already added ogm.properties, the same way I did when I was using neo4j repositories only. But it seems they no longer get applied. So I added following into application.properties.

 spring.data.neo4j.password=neo4j
 spring.data.neo4j.username=neo4j

Second question is, how can I configure neo4j just as the same way I did only with neo4j? I have defined following in ogm.properties. How can I apply this into neo4j configurations?

 #Driver, required
 driver=org.neo4j.ogm.drivers.bolt.driver.BoltDriver

 #URI of the Neo4j database, required. If no port is specified, the          
 #default port 7687 is used. Otherwise, a port can be specified with   
 #bolt://neo4j:password@localhost:1234

 URI=bolt://neo4j:neo4j@localhost

 #Connection pool size (the maximum number of sessions per URL),    
 #optional, defaults to 50

 connection.pool.size=150

 #Encryption level (TLS), optional, defaults to REQUIRED. Valid  
 #values are NONE,REQUIRED

 encryption.level=NONE

With the above changes, now it is giving following error.

 org.neo4j.ogm.exception.MappingException: No identity field found for class: org.rozzie.processor.models.dao.cassandra.FlightDAO

Note that a neo4j.ogm exception is thrown for the cassandra models. What is happening under the hood. How can I configure these two databases with spring boot in one project as above?

回答1:

This looks like the Spring Boot autoconfiguration is not able to handle multiple Spring Data projects at the same time.

Please refer to documentation for Spring Data Neo4j and Spring Data Cassandra

In particular you should point SDN module to neo4j repositories only

@EnableNeo4jRepositories(basePackages = "org.test.project.repositories.neo")

and similarly for cassandra.

回答2:

I have used neo4j with mongo. I don't see any issues. I presume it should be same with cassandra. This is all the configuration I have

@SpringBootApplication
@EnableConfigurationProperties
@EnableNeo4jRepositories("com.in.neo4j.repository.neo")
@EnableMongoRepositories("com.in.neo4j.repository.mongo")
public class Neo4JApplication {
    public static void main(String[] args) {
        SpringApplication.run(Neo4JApplication.class, args);
    }
}

And in my properties file I have

spring.data.neo4j.username=neo4j  
spring.data.neo4j.password=admin  

spring.data.mongodb.database=blah  
spring.data.mongodb.host=blahblah  
spring.data.mongodb.port=27017

来源：https://stackoverflow.com/questions/44033599/how-to-configure-neo4j-and-cassandra-repositories-in-same-spring-boot-applicatio