org.apache.storm.mongodb.common.mapper

## Interface MongoLookupMapper

- All Superinterfaces:
    Serializable
  All Known Implementing Classes:
    SimpleMongoLookupMapper

      public interface MongoLookupMapper
      extends Serializable

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `declareOutputFields(OutputFieldsDeclarer declarer)` declare what are the fields that this code will output.
    `List<Values>` | `toTuple(ITuple input, org.bson.Document doc)` Converts a Mongo document to a list of storm values that can be emitted.

- - ### Method Detail

    - #### toTuple

          List<Values> toTuple(ITuple input,
                               org.bson.Document doc)

      Converts a Mongo document to a list of storm values that can be emitted. This is done to allow a single storm input tuple and a single Mongo document to result in multiple output values.

      Parameters:
        `input` - the input tuple.
        `doc` - the mongo document
      Returns:
        a List of storm values that can be emitted. Each item in list is emitted as an output tuple.

    - #### declareOutputFields

          void declareOutputFields(OutputFieldsDeclarer declarer)

      declare what are the fields that this code will output.

      Parameters:
        `declarer` - OutputFieldsDeclarer

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