Command failed with error 9: 'The 'cursor' option is required, except for aggregate with the explain

首先上异常

com.mongodb.MongoCommandException: Command failed with error 9: 'The 'cursor' option is required, except for aggregate with the explain argument' on server 193.112.59.74:28017. The full response is { "ok" : 0.0, "errmsg" : "The 'cursor' option is required, except for aggregate with the explain argument", "code" : 9, "codeName" : "FailedToParse" }
    at com.mongodb.connection.ProtocolHelper.getCommandFailureException(ProtocolHelper.java:115)
    at com.mongodb.connection.CommandProtocol.execute(CommandProtocol.java:114)
    at com.mongodb.connection.DefaultServer$DefaultServerProtocolExecutor.execute(DefaultServer.java:168)
    at com.mongodb.connection.DefaultServerConnection.executeProtocol(DefaultServerConnection.java:289)
    at com.mongodb.connection.DefaultServerConnection.command(DefaultServerConnection.java:176)
    at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:216)
    at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:207)
    at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:113)
    at com.mongodb.operation.AggregateOperation$1.call(AggregateOperation.java:257)