TO MAP

This function aggregates an input stream to a Map.

For example, you can aggregate a stream of persons to a Map<String,Integer> with the full name as key and the age as value.

See Also
Operators
Expression Language
Defining and Managing Data Queries
Parameter Description
filterExpression An Apollo expression to keep some elements only. It is useful to process the aggregation on a subpart of your input stream.
keyExpression An Apollo expression extracting the key element for the Map. For example, person.fullname.
valueExpression An Apollo expression extracting the value element for the map. For example: person.age.
multiValued If true, the value element is a List. Default: false.