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improvement of the article "How to Return Multiple Values From a Java Method"
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‎core-java-modules/core-java-lang-2/pom.xml‎

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</parent>
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<dependencies>
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<dependency>
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<groupId>org.apache.commons</groupId>
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<artifactId>commons-lang3</artifactId>
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<version>3.9</version>
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</dependency>
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<dependency>
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<groupId>commons-beanutils</groupId>
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<artifactId>commons-beanutils</artifactId>

‎core-java-modules/core-java-lang-2/src/main/java/com/baeldung/methodmultiplereturnvalues/MultipleReturnValuesUsingApacheCommonsPair.java‎

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package com.baeldung.methodmultiplereturnvalues;
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import org.apache.commons.lang3.tuple.ImmutablePair;
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import org.apache.commons.lang3.tuple.Pair;
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import java.util.Comparator;
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import java.util.List;
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class MultipleReturnValuesUsingApacheCommonsPair {
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static ImmutablePair<Coordinates, Double> getMostDistantPoint(
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List<Coordinates> coordinatesList,
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Coordinates target) {
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return coordinatesList.stream()
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.map(coordinates -> ImmutablePair.of(coordinates, coordinates.calculateDistance(target)))
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.max(Comparator.comparingDouble(Pair::getRight))
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.get();
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}
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}

‎core-java-modules/core-java-lang-2/src/main/java/com/baeldung/methodmultiplereturnvalues/MultipleReturnValuesUsingApacheCommonsTriple.java‎

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package com.baeldung.methodmultiplereturnvalues;
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import org.apache.commons.lang3.tuple.ImmutableTriple;
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import java.util.List;
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import java.util.stream.Collectors;
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class MultipleReturnValuesUsingApacheCommonsTriple {
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static ImmutableTriple<Double, Double, Double> getMinAvgMaxTriple(
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List<Coordinates> coordinatesList,
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Coordinates target) {
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List<Double> distanceList = coordinatesList.stream()
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.map(coordinates -> coordinates.calculateDistance(target))
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.collect(Collectors.toList());
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Double minDistance = distanceList.stream().mapToDouble(Double::doubleValue).min().getAsDouble();
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Double avgDistance = distanceList.stream().mapToDouble(Double::doubleValue).average().orElse(0.0D);
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Double maxDistance = distanceList.stream().mapToDouble(Double::doubleValue).max().getAsDouble();
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return ImmutableTriple.of(minDistance, avgDistance, maxDistance);
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}
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}

‎core-java-modules/core-java-lang-2/src/test/java/com/baeldung/methodmultiplereturnvalues/MultipleReturnValuesUsingApacheCommonsPairUnitTest.java‎

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package com.baeldung.methodmultiplereturnvalues;
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import org.apache.commons.lang3.tuple.ImmutablePair;
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import org.junit.jupiter.api.Test;
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import java.math.BigDecimal;
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import java.math.RoundingMode;
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import java.util.ArrayList;
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import java.util.List;
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import static org.junit.jupiter.api.Assertions.assertEquals;
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class MultipleReturnValuesUsingApacheCommonsPairUnitTest {
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@Test
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void whenUsingPair_thenMultipleFieldsAreReturned() {
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List<Coordinates> coordinatesList = new ArrayList<>();
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coordinatesList.add(new Coordinates(1, 1, "home"));
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coordinatesList.add(new Coordinates(2, 2, "school"));
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coordinatesList.add(new Coordinates(3, 3, "hotel"));
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Coordinates target = new Coordinates(5, 5, "gym");
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ImmutablePair<Coordinates, Double> mostDistantPoint = MultipleReturnValuesUsingApacheCommonsPair.getMostDistantPoint(coordinatesList, target);
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assertEquals(1, mostDistantPoint.getLeft().getLongitude());
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assertEquals(1, mostDistantPoint.getLeft().getLatitude());
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assertEquals("home", mostDistantPoint.getLeft().getPlaceName());
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assertEquals(5.66, BigDecimal.valueOf(mostDistantPoint.getRight()).setScale(2, RoundingMode.HALF_UP).doubleValue());
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}
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}

‎core-java-modules/core-java-lang-2/src/test/java/com/baeldung/methodmultiplereturnvalues/MultipleReturnValuesUsingApacheCommonsTripleUnitTest.java‎

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package com.baeldung.methodmultiplereturnvalues;
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import org.apache.commons.lang3.tuple.ImmutableTriple;
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import org.junit.jupiter.api.Test;
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import java.math.BigDecimal;
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import java.math.RoundingMode;
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import java.util.ArrayList;
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import java.util.List;
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import static org.junit.jupiter.api.Assertions.assertEquals;
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class MultipleReturnValuesUsingApacheCommonsTripleUnitTest {
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@Test
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void whenUsingTriple_thenMultipleFieldsAreReturned() {
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List<Coordinates> coordinatesList = new ArrayList<>();
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coordinatesList.add(new Coordinates(1, 1, "home"));
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coordinatesList.add(new Coordinates(2, 2, "school"));
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coordinatesList.add(new Coordinates(3, 3, "hotel"));
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Coordinates target = new Coordinates(5, 5, "gym");
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ImmutableTriple<Double, Double, Double> minAvgMax = MultipleReturnValuesUsingApacheCommonsTriple.getMinAvgMaxTriple(coordinatesList, target);
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assertEquals(2.83, scaleDouble(minAvgMax.left)); //min
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assertEquals(4.24, scaleDouble(minAvgMax.middle)); //avg
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assertEquals(5.66, scaleDouble(minAvgMax.right)); //max
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}
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private double scaleDouble(Double d) {
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return BigDecimal.valueOf(d).setScale(2, RoundingMode.HALF_UP).doubleValue();
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}
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}

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