Example usage for org.apache.commons.collections4 SetValuedMap keySet

Introduction

In this page you can find the example usage for org.apache.commons.collections4 SetValuedMap keySet.

Prototype

Set<K> keySet();

Source Link

Document

Returns a Set view of the keys contained in this multi-valued map.

Usage

From source file:org.decampo.examples.collections.MoreCollectorsTest.java

@Test
public void groupingByDistinctTest() throws Exception {
    final Num[] english = { new Num(0, "zero"), new Num(1, "one"), new Num(2, "two") };
    final Num[] espanol = { new Num(0, "cero"), new Num(1, "uno"), new Num(2, "dos") };
    final Num[] deutsche = { new Num(0, "null"), new Num(1, "eins"), new Num(2, "zwei") };

    final SetValuedMap<Integer, Num> result = Stream.of(english, espanol, deutsche, espanol, english)
            .flatMap(Arrays::stream).collect(MoreCollectors.groupingByDistinct(Num::getValue));

    assertEquals(new HashSet<>(Arrays.asList(0, 1, 2)), result.keySet());
    assertEquals(new HashSet<>(Arrays.asList(english[0], espanol[0], deutsche[0])), result.get(0));
    assertEquals(new HashSet<>(Arrays.asList(english[1], espanol[1], deutsche[1])), result.get(1));
    assertEquals(new HashSet<>(Arrays.asList(english[2], espanol[2], deutsche[2])), result.get(2));
}

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