Cassandra会话在运行时为空

我使用的代码如下:

import java.util.ArrayList;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.data.cassandra.config.CassandraClusterFactoryBean;
import org.springframework.data.cassandra.config.CassandraSessionFactoryBean;
import org.springframework.data.cassandra.config.SchemaAction;
import org.springframework.data.cassandra.convert.CassandraConverter;
import org.springframework.data.cassandra.core.CassandraOperations;
import org.springframework.data.cassandra.core.CassandraTemplate;
import org.springframework.stereotype.Component;

@Component
public class KeyspaceSession {

    @Autowired
    @Qualifier("cluster")
    CassandraClusterFactoryBean cluster;

    @Autowired
    @Qualifier("converter")
    CassandraConverter converter;


    public List<CassandraOperations> getTemplates(){
        List<CassandraOperations> listOfTemplates = new ArrayList<>();
        for(CassandraKeyspaces keyspace : CassandraKeyspaces.values()){
            CassandraSessionFactoryBean session = new CassandraSessionFactoryBean();
            session.setCluster(cluster.getObject());
            session.setKeyspaceName(keyspace.getKeyspace());
            session.setConverter(converter);
            session.setSchemaAction(SchemaAction.CREATE_IF_NOT_EXISTS); 
            CassandraOperations op = new CassandraTemplate(session.getObject());
            listOfTemplates.add(op);
        }
        return listOfTemplates;
    }

}

我从服务器得到以下答案:

{
  "timestamp": 1505204641753,
  "status": 500,
  "error": "Internal Server Error",
  "exception": "java.lang.IllegalArgumentException",
  "message": "Session must not be null",
  "path": "/getUser/10/pl"
}