Package org.apache.druid.query.extraction

Class LowerExtractionFn

java.lang.Object
org.apache.druid.query.extraction.DimExtractionFn
org.apache.druid.query.extraction.LowerExtractionFn
All Implemented Interfaces:
Cacheable, ExtractionFn
public class LowerExtractionFn extends DimExtractionFn

  • Constructor Details

    • LowerExtractionFn

      public LowerExtractionFn(String localeString)

  • Method Details

    • apply

      @Nullable public String apply(@Nullable String key)
      Description copied from interface: ExtractionFn
      The "extraction" function. This should map a String value into some other String value.

      Like ExtractionFn.apply(Object), the empty string is considered invalid output for this method and it should instead return null.

      Parameters:
      key - string input of extraction function
      Returns:
      new string with all of the characters in key as an lower case or null if key is empty or null

    • preservesOrdering

      public boolean preservesOrdering()
      Description copied from interface: ExtractionFn
      Offers information on whether the extraction will preserve the original ordering of the values.

      Some optimizations of queries is possible if ordering is preserved. Null values *do* count towards ordering.

      Returns:
      true if ordering is preserved, false otherwise

    • getExtractionType

      public ExtractionFn.ExtractionType getExtractionType()
      Description copied from interface: ExtractionFn
      A dim extraction can be of one of two types, renaming or rebucketing. In the `ONE_TO_ONE` case, a unique values is modified into another unique value. In the `MANY_TO_ONE` case, there is no longer a 1:1 relation between old dimension value and new dimension value
      Returns:
      ExtractionFn.ExtractionType declaring what kind of manipulation this function does

    • getCacheKey

      public byte[] getCacheKey()
      Description copied from interface: Cacheable
      Get a byte array used as a cache key.
      Returns:
      bytes to be used as cache key - or null if this object should not be cached.

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object