# tJavaMR

Provides an editor that enables you to enter personalized MapReduce code in order to integrate it in Talend program.

tJavaMR makes it possible to extend the functionalities of a Talend Job through writing custom map and reduce methods. You can execute this code only once.

This component appears only when you are creating a Map/Reduce Job.

For more technologies supported by Talend, see [Talend components](https://help.qlik.com/talend/r/en-US/7.3/components/java-custom-code-for-map-reduce).

### In this section

* [tJavaMR MapReduce properties (deprecated)](https://help.qlik.com/talend/en-US/components/7.3/java-custom-code-for-map-reduce/tjavamr-mapreduce-properties-deprecated)

**Related concepts**

[Counting words using custom map and reduce code (deprecated)](https://help.qlik.com/talend/en-US/components/7.3/java-custom-code-for-map-reduce/tjavamr-thdfsoutput-thdfsinput-tfileinputdelimited-counting-words-using-custom-map-and-reduce-code-deprecated-inspired)