20.13. Transformation Function Overview

20.13.1. Type Conversions

  • ::int or ::integer
  • ::long
  • ::float
  • ::double
  • ::boolean
  • ::r
  • stringToInt or stringToInteger
  • stringToLong
  • stringToFloat
  • stringToDouble
  • stringToBoolean

20.13.2. String Functions

  • strip
  • stripPrefix
  • stripSuffix
  • stripQuotes
  • replace
  • removeChars
  • length
  • trim
  • capitalize
  • lowercase
  • regexReplace
  • concatenate
  • substring
  • toString
  • emptyToNull
  • printf

20.13.3. Date Functions

  • now
  • date
  • dateTime
  • basicIsoDate
  • isoLocalDate
  • basicDateTime
  • isoLocalDateTime
  • isoOffsetDateTime
  • basicDateTimeNoMillis
  • dateHourMinuteSecondMillis
  • millisToDate
  • secsToDate

20.13.4. Geometry Functions

  • point
  • multipoint
  • linestring
  • multilinestring
  • polygon
  • multipolygon
  • geometrycollection
  • geometry
  • projectFrom

20.13.5. ID Functions

  • stringToBytes
  • md5
  • murmur3_32
  • murmur3_128
  • uuid
  • uuidZ3
  • uuidZ3Centroid
  • base64

20.13.6. Math Functions

  • add
  • subtract
  • multiply
  • divide
  • mean
  • min
  • max

20.13.7. List and Map Functions

  • list
  • mapValue
  • parseList
  • parseMap

20.13.8. Control Functions

  • try
  • withDefault

20.13.9. State Functions

  • inputFilePath
  • lineNo

20.13.10. Functions defined using scripting languages

You can define functions using scripting languages that support JSR-223. This is currently tested with JavaScript only as it is natively supported in all JREs via the Nashorn extension. To define a JavaScript function for use in the converter framework, create a file with the .js extension and the function definition as the contents of the file. For instance, if you have defined a function such as

function hello(s) {
   return "hello: " + s;
}

you can reference that function in a transform expression as js:hello($2)

20.13.11. Installing Custom Scripts

Custom scripting functions are made available to GeoMesa comamnd line tools or distributed (map-reduce) ingest via including them on the classpath or setting a system property.

For local usage, geomesa defines the system property geomesa.convert.scripts.path to be a colon-separated list of script files and/or directories containing scripts. This system property can be set when using the command line tools by setting the CUSTOM_JAVA_OPTS environmental variable:

CUSTOM_JAVA_OPTS="-Dgeomesa.convert.scripts.path=/path/to/script.js:/path/to/script-dir/"

A more resilient method of including custom scripts is to package them as a JAR or ZIP file and add it to the GEOMESA_EXTRA_CLASSPATHS environmental variable. If using maven you can simply package them in a folder under src/main/resources/geomesa-convert-scripts/ which will create a folder in your jar file named geomesa-convert-scripts with the scripts inside. You can manually create a jar with this folder as well. An easier way is often to package them as a zip archive with a folder similary named geomesa-convert-scripts inside the archive containing the scripts:

$ unzip -l /tmp/scripts.zip
Archive:  /tmp/scripts.zip
  Length      Date    Time    Name
---------  ---------- -----   ----
        0  2017-03-09 11:33   geomesa-convert-scripts/
       42  2017-03-09 11:33   geomesa-convert-scripts/my-script.js
---------                     -------
       42                     2 files

For either zip or jar files add them to the extra classpaths in your environment to make them available for the tools or map-reduce ingest:

GEOMESA_EXTRA_CLASSPATHS="/path/to/my-scripts.jar:/tmp/scripts.zip"

A example of ingest with a scripts on the classpath is below:

GEOMESA_EXTRA_CLASSPATHS="/tmp/scripts.zip:/path/to/my-scripts.jar" bin/geomesa-accumulo ingest -u <user-name>
-p <password> -s <sft-name> -C <converter-name> -c geomesa.catalog hdfs://localhost:9000/data/example.csv

You can also verify the classpath is properly configured with the tools:

GEOMESA_EXTRA_CLASSPATHS="/tmp/scripts.zip:/path/to/my-scripts.jar" bin/geomesa-accumulo classpath

20.13.12. CQL Functions

Most of the basic CQL functions are available as transformations. To use one, invoke it like a regular function, prefixed with the cql namespace. For example, you can use the CQL buffer function to turn a point into a polygon:

cql:buffer($1, 2.0)

For more information on the various CQL functions, see the GeoServer filter function reference.

20.13.13. JSON/Avro Transformations

See JSON Transform Functions and Avro Transform Functions.

20.13.14. Enrichment Functions

The converter framework provides a mechanism for setting an attribute based on a lookup from a cache. The cache can be a literal cache in the system or in an external system such as Redis.

  • cacheLookup