Package org.apache.storm.trident.operation

## Interface Filter

- All Superinterfaces:
    `EachOperation`, `Operation`, `Serializable`
  All Known Implementing Classes:
    `BaseFilter`, `Debug`, `Equals`, `FilterNull`, `Negate`, `TrueFilter`, `TrueFilter`

      public interface Filter
      extends EachOperation

  Filters take in a tuple as input and decide whether or not to keep that tuple or not.

  If the `isKeep()` method of a Filter returns `false` for a tuple, that tuple will be filtered out of the Stream

  ### Configuration If your `Filter` implementation has configuration requirements, you will typically want to extend `BaseFilter` and override the `Operation.prepare(Map, TridentOperationContext)` method to perform your custom initialization.

  See Also:
    `Stream`

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `boolean` | `isKeep​(TridentTuple tuple)` | Determines if a tuple should be filtered out of a stream.

    - ### Methods inherited from interface org.apache.storm.trident.operation.Operation

      `cleanup, prepare`

- - ### Method Detail

    - #### isKeep

          boolean isKeep​(TridentTuple tuple)

      Determines if a tuple should be filtered out of a stream.
      Parameters:
        `tuple` - the tuple being evaluated
      Returns:
        `false` to drop the tuple, `true` to keep the tuple