Apache Beam + Kotlin = ❤️

Harshit Dwivedi
Aug 23 · 2 min read

Code Snippets

String Templating

String filename = String.format(
"%s-%s-of-%s",
filenamePrefix,
shardNumber,
numShards);
// String templating
val filename = "$filenamePrefix-$shardNumber-of-$numShards"

Single Line Functions

public static class FormatAsTextFn extends SimpleFunction<KV<String, Long>, String> {
@Override
public String apply(KV<String, Long> input) {
return input.getKey() + ": " + input.getValue();
}
}
public class FormatAsTextFn : SimpleFunction<KV<String, Long>, String>() {
override fun apply(input: KV<String, Long>) = "${input.key} : ${input.value}" //Single line functions
}

Null Checks

if(tableRow != null){
formatAndInsert(tableRow);
}
tableRow?.let{
formatAndInsert(it) // No need for null checks
}

Type Inferencing

String tableName = "testTable";
val tableName = "testTable"  // Type inferencing

Contributors Welcomed!

Harshit Dwivedi

Written by

Android Developer, has an *approximate* knowledge of many things. https://harshit.app/

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