mongdb 使用聚合函数异常

异常信息： 

Command execution failed:  Error [The 'cursor' option is required, except for aggregate with the explain argument], Command = { "aggregate" : "mg_day_statistics" , "pipeline" : [ { "$match" : { "_id" : { "$exists" : true}}} , { "$group" : { "_id" :  null  , "totalAmount" : { "$sum" : "$amount"}}}]}; nested exception is com.mongodb.MongoCommandException: Command failed with error 9: 'The 'cursor' option is required, except for aggregate with the explain argument' on server 120.24.38.204:28018. The full response is { "ok" : 0.0, "errmsg" : "The 'cursor' option is required, except for aggregate with the explain argument", "code" : 9, "codeName" : "FailedToParse" }

异常原因：这是 springboot  1.5.8.RELEASE 的  bug  修改成  1.5.10.RELEASE 就可以了

<groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.10.RELEASE</version>
        <relativePath/>