无法从Apache Camel MongoDb组件检索多个对象

我有以下代码摘录:

@Component
public class RetrievalAllFromDbRoute extends RouteBuilder{
    public void configure() throws Exception {
        this.from("direct:allObjects").routeId("retrieveAllObjectsFromDB")
                .setHeader("CamelMongoDbBatchSize", constant(50))
                .process(new Processor() {
                    public void process(Exchange exchange) throws Exception {
                        DBObject fieldFilter = BasicDBObjectBuilder.start().add("_id", 1).get();
                        exchange.getMessage().setHeader(MongoDbConstants.FIELDS_FILTER, fieldFilter);
                    }
                })
                .to("mongodb:mongoClient?database="+mongoDbName +"&collection=myObjectCollection&operation=findAll&outputType=DBCursor")
                .split(body())
                .streaming()
                .process(new Processor() {
                    public void process(Exchange exchange) throws Exception {
                        JsonNode idNode = UtilMethods.convertStringToJson(exchange.getMessage().getBody().toString());
                        exchange.getMessage().setBody(idNode.get("_id").asText());
                        System.out.println("\n Extracted id["+exchange.getMessage().getBody().toString()+"] from db \n");
                    }
                });
    }
}

在第一个处理器中设置断点并查询数据库会发现数据库中有300多个对象,所以我不明白为什么我只得到一个对象。

编辑 :
我的maven POM依赖项:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-mongodb</artifactId>
    <version>2.22.0</version>
</dependency>

使用MongoDB 3.6数据库