Java 8 Streams - Collectors.summarizingDouble Examples

The static method, Collectors.summarizingDouble() returns a Collector which applies a mapping function to each input element of type T to convert it to primitive double, and returns summary statistics for the resulting values.


<T> Collector<T,?,DoubleSummaryStatistics> summarizingDouble(ToDoubleFunction<? super T> mapper)

Examples

package com.logicbig.example.collectors;

import java.math.BigDecimal;
import java.util.DoubleSummaryStatistics;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class SummarizingDoubleExample {
    public static void main (String[] args) {

        Stream<BigDecimal> s = Stream.iterate(
                            BigDecimal.ONE, bigDecimal ->
                                       bigDecimal.add(BigDecimal.ONE))
                                      .limit(10).peek(System.out::println);

        DoubleSummaryStatistics d = s.collect(Collectors.summarizingDouble
                                                  (BigDecimal::doubleValue));
        System.out.println(d);
    }
}

Output

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DoubleSummaryStatistics{count=10, sum=55.000000, min=1.000000, average=5.500000, max=10.000000}

Original Post

Java 8 Streams - Collectors.summarizingDouble Examples

Examples

Output

See Also