Merge branch 'master' of https://github.com/eugenp/tutorials into BAEL-4461-3

This commit is contained in:
amit2103 2018-07-16 20:49:40 +05:30
commit 4b1aeb776f
5 changed files with 325 additions and 0 deletions

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package com.baeldung.java10.list;
import org.junit.Test;
import java.util.Arrays;
import java.util.List;
public class CopyListServiceUnitTest {
@Test(expected = UnsupportedOperationException.class)
public void whenModifyCopyOfList_thenThrowsException() {
List<Integer> copyList = List.copyOf(Arrays.asList(1, 2, 3, 4));
}
}

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package com.baeldung.list;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Optional;
import java.util.stream.Collectors;
import java.util.stream.Stream;
public class CopyListService {
public List<Flower> copyListByConstructor(List<Flower> source) {
return new ArrayList<Flower>(source);
}
public List<Flower> copyListByConstructorAndEditOneFlowerInTheNewList(List<Flower> source) {
List<Flower> flowers = new ArrayList<>(source);
if(flowers.size() > 0) {
flowers.get(0).setPetals(flowers.get(0).getPetals() * 3);
}
return flowers;
}
public List<Flower> copyListByAddAllMethod(List<Flower> source) {
List<Flower> flowers = new ArrayList<>();
flowers.addAll(source);
return flowers;
}
public List<Flower> copyListByAddAllMethodAndEditOneFlowerInTheNewList(List<Flower> source) {
List<Flower> flowers = new ArrayList<>();
flowers.addAll(source);
if(flowers.size() > 0) {
flowers.get(0).setPetals(flowers.get(0).getPetals() * 3);
}
return flowers;
}
public List<Integer> copyListByCopyMethod(List<Integer> source, List<Integer> dest) {
Collections.copy(dest, source);
return dest;
}
public List<Flower> copyListByStream(List<Flower> source) {
return source.stream().collect(Collectors.toList());
}
public List<Flower> copyListByStreamAndSkipFirstElement(List<Flower> source) {
return source.stream().skip(1).collect(Collectors.toList());
}
public List<Flower> copyListByStreamWithFilter(List<Flower> source, Integer moreThanPetals) {
return source.stream().filter(f -> f.getPetals() > moreThanPetals).collect(Collectors.toList());
}
public List<Flower> copyListByStreamWithOptional(List<Flower> source) {
return Optional.ofNullable(source)
.map(List::stream)
.orElseGet(Stream::empty)
.collect(Collectors.toList());
}
public List<Flower> copyListByStreamWithOptionalAndSkip(List<Flower> source) {
return Optional.ofNullable(source)
.map(List::stream)
.orElseGet(Stream::empty)
.skip(1)
.collect(Collectors.toList());
}
}

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package com.baeldung.list;
public class Flower {
private String name;
private int petals;
public Flower(String name, int petals) {
this.name = name;
this.petals = petals;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getPetals() {
return petals;
}
public void setPetals(int petals) {
this.petals = petals;
}
}

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package com.baeldung.list;
import org.junit.Before;
import org.junit.Test;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import static org.junit.Assert.*;
public class CopyListServiceUnitTest {
List<Flower> flowers;
private CopyListService copyListService;
@Before
public void init() {
this.copyListService = new CopyListService();
this.flowers = new ArrayList<>();
Flower poppy = new Flower("Poppy", 12);
flowers.add(poppy);
Flower anemone = new Flower("Anemone", 8);
flowers.add(anemone);
Flower catmint = new Flower("Catmint", 12);
flowers.add(catmint);
Flower diascia = new Flower("Diascia", 5);
flowers.add(diascia);
Flower iris = new Flower("Iris", 3);
flowers.add(iris);
Flower pansy = new Flower("Pansy", 5);
flowers.add(pansy);
}
@Test
public void givenAList_whenListDoesNotHaveNullElements_thenReturnAnotherListWithTheSameElementsByConstructor() {
List<Flower> copy = copyListService.copyListByConstructor(flowers);
assertEquals(copy.size(), flowers.size());
assertTrue(copy.containsAll(flowers));
}
@Test
public void givenAList_whenListDoesNotHaveNullElements_thenReturnAnotherListWithOneModifiedElementByConstructor() {
List<Flower> copy = copyListService.copyListByConstructorAndEditOneFlowerInTheNewList(flowers);
assertEquals(copy.size(), flowers.size());
assertTrue(copy.containsAll(flowers));
}
@Test
public void givenAList_whenListDoesNotHaveNullElements_thenReturnAnotherListWithTheSameElementsByAddAllmethod() {
List<Flower> copy = copyListService.copyListByAddAllMethod(flowers);
assertEquals(copy.size(), flowers.size());
assertTrue(copy.containsAll(flowers));
}
@Test
public void givenAList_whenListDoesNotHaveNullElements_thenReturnAnotherListWithOneModifiedElementByAddAllmethod() {
List<Flower> copy = copyListService.copyListByAddAllMethodAndEditOneFlowerInTheNewList(flowers);
assertEquals(copy.size(), flowers.size());
assertTrue(copy.containsAll(flowers));
}
@Test
public void givenAList_whenListsHaveSameSize_thenReturnAnotherListWithTheSameElementsByCopyMethod() {
List<Integer> source = Arrays.asList(1,2,3);
List<Integer> dest = Arrays.asList(4,5,6);
dest = copyListService.copyListByCopyMethod(source, dest);
assertEquals(dest.size(), source.size());
assertTrue(dest.containsAll(source));
}
@Test
public void givenAList_whenListsHaveDifferentSize_thenReturnAnotherListWithTheSameElementsByCopyMethod() {
List<Integer> source = Arrays.asList(1,2,3);
List<Integer> dest = Arrays.asList(5,6,7,8,9,10);
dest = copyListService.copyListByCopyMethod(source, dest);
assertNotEquals(dest.size(), source.size());
assertTrue(dest.containsAll(source));
}
@Test
public void givenAList_whenListDoesNotHaveNullElements_thenReturnAnotherListWithTheSameElementsByStreamProcess() {
List<Flower> copy = copyListService.copyListByStream(flowers);
assertEquals(copy.size(), flowers.size());
assertTrue(copy.containsAll(flowers));
}
@Test
public void givenAList_whenListDoesNotHaveNullElements_thenReturnAnotherListWithOneElementLessByStreamProcess() {
List<Flower> copy = copyListService.copyListByStreamAndSkipFirstElement(flowers);
assertNotEquals(copy.size(), flowers.size());
assertEquals(copy.size() + 1, flowers.size());
assertFalse(copy.containsAll(flowers));
}
@Test
public void givenAList_whenListDoesNotHaveNullElements_thenReturnAnotherListWithFilterElementsByStreamProcess() {
List<Flower> copy = copyListService.copyListByStreamWithFilter(flowers, 5);
assertNotEquals(copy.size(), flowers.size());
assertEquals(copy.size() + 3, flowers.size());
assertFalse(copy.containsAll(flowers));
}
@Test
public void givenAList_whenListIsNull_thenReturnEmptyListByStreamProcess() {
List<Flower> copy = copyListService.copyListByStreamWithOptional(null);
assertNotNull(copy);
assertEquals(copy.size(), 0);
}
@Test
public void givenAList_whenListIsNotNull_thenReturnAnotherListWithTheElementsByStreamProcess() {
List<Flower> copy = copyListService.copyListByStreamWithOptional(flowers);
assertEquals(copy.size(), flowers.size());
assertTrue(copy.containsAll(flowers));
}
@Test
public void givenAList_whenListIsNotNull_thenReturnAnotherListWithOneElementLessByStreamProcess() {
List<Flower> copy = copyListService.copyListByStreamWithOptionalAndSkip(flowers);
assertNotEquals(copy.size(), flowers.size());
assertEquals(copy.size() + 1, flowers.size());
assertFalse(copy.containsAll(flowers));
}
}

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package com.baeldung.java.set;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;
import org.junit.jupiter.api.Test;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import static org.junit.Assert.assertEquals;
public class HashSetInitalizingUnitTest {
@Test
public void whenUsingJava_usingArraysStaticMethod_thenCorrectSize() {
Set<String> set = new HashSet<>(Arrays.asList("a", "b", "c"));
assertEquals(3, set.size());
}
@Test
public void whenUsingJava_usingAnonymousClass_thenCorrectSize() {
Set<String> set = new HashSet<String>(){{
add("a");
add("b");
add("c");
}};
assertEquals(3, set.size());
}
@Test
public void whenUsingJava_creatingSingletonSet_thenCorrectSize() {
Set<String> set = Collections.singleton("a");
assertEquals(1, set.size());
}
public static final <T> Set<T> newHashSet(T... objs) {
Set<T> set = new HashSet<T>();
Collections.addAll(set, objs);
return set;
}
@Test
public void whenUsingJava_usingCustomStaticUtilMethod_thenCorrectSize() {
Set<String> set = newHashSet("a","b","c");
assertEquals(3, set.size());
}
@Test
public void whenUsingJava8_usingCollectOnStream_thenCorrectSize() {
Set<String> set = Stream.of("a", "b", "c").collect(Collectors.toSet());
assertEquals(3, set.size());
}
@Test
public void whenUsingJava8_fromStringArray_thenCorrectSize() {
String[] stringArray = {"a","b","c"};
Set<String> set = Arrays.stream(stringArray).collect(Collectors.toCollection(HashSet::new));
assertEquals(3, set.size());
}
// Requires Java9 - uncomment if you are using Java 9 or higher
/*@Test
public void whenUsingJava9_usingCollectOnStream_thenCorrectSize() {
Set set = Set.of("a", "b", "c");
assertEquals(3, set.size());
}*/
@Test
public void whenUsingGoogleGuava_createMutableSet_thenCorrectSize() {
Set<String> set = Sets.newHashSet("a", "b", "c");
assertEquals(3, set.size());
}
@Test
public void whenUsingGoogleGuava_createImmutableSet_thenCorrectSize() {
Set<String> set = ImmutableSet.of("a", "b", "c");
assertEquals(3, set.size());
}
}