Merge branch 'master' into master

This commit is contained in:
Loredana Crusoveanu
2019-07-06 23:27:06 +03:00
committed by GitHub
68 changed files with 1878 additions and 366 deletions
+7
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@@ -22,6 +22,7 @@
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<icu.version>64.2</icu.version>
<assertj.version>3.12.2</assertj.version>
</properties>
<dependencies>
@@ -30,6 +31,12 @@
<artifactId>icu4j</artifactId>
<version>${icu.version}</version>
</dependency>
<dependency>
<groupId>org.assertj</groupId>
<artifactId>assertj-core</artifactId>
<version>${assertj.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
@@ -0,0 +1,164 @@
package com.baeldung.bifunction;
import org.junit.Test;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.function.BiFunction;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import static org.assertj.core.api.Assertions.assertThat;
public class BiFunctionalInterfacesUnitTest {
@Test
public void givenStreamValues_whenMappedToNewValues() {
List<String> mapped = Stream.of("hello", "world")
.map(word -> word + "!")
.collect(Collectors.toList());
assertThat(mapped).containsExactly("hello!", "world!");
}
@Test
public void givenStreamValues_whenReducedWithPrefixingOperation() {
String result = Stream.of("hello", "world")
.reduce("", (a, b) -> b + "-" + a);
assertThat(result).isEqualTo("world-hello-");
}
@Test
public void givenStreamValues_whenReducedWithPrefixingLambda_thenHasNoTrailingDash() {
String result = Stream.of("hello", "world")
.reduce("", (a, b) -> combineWithoutTrailingDash(a, b));
assertThat(result).isEqualTo("world-hello");
}
private String combineWithoutTrailingDash(String a, String b) {
if (a.isEmpty()) {
return b;
}
return b + "-" + a;
}
@Test
public void givenStreamValues_whenReducedWithPrefixingMethodReference_thenHasNoTrailingDash() {
String result = Stream.of("hello", "world")
.reduce("", this::combineWithoutTrailingDash);
assertThat(result).isEqualTo("world-hello");
}
@Test
public void givenTwoLists_whenCombined() {
List<String> list1 = Arrays.asList("a", "b", "c");
List<Integer> list2 = Arrays.asList(1, 2, 3);
List<String> result = new ArrayList<>();
for (int i=0; i < list1.size(); i++) {
result.add(list1.get(i) + list2.get(i));
}
assertThat(result).containsExactly("a1", "b2", "c3");
}
@Test
public void givenTwoLists_whenCombinedWithGeneralPurposeCombiner() {
List<String> list1 = Arrays.asList("a", "b", "c");
List<Integer> list2 = Arrays.asList(1, 2, 3);
List<String> result = listCombiner(list1, list2, (a, b) -> a + b);
assertThat(result).containsExactly("a1", "b2", "c3");
}
private static <T, U, R> List<R> listCombiner(List<T> list1,
List<U> list2,
BiFunction<T, U, R> combiner) {
List<R> result = new ArrayList<>();
for (int i = 0; i < list1.size(); i++) {
result.add(combiner.apply(list1.get(i), list2.get(i)));
}
return result;
}
@Test
public void givenTwoLists_whenComparedWithCombiningFunction() {
List<Double> list1 = Arrays.asList(1.0d, 2.1d, 3.3d);
List<Float> list2 = Arrays.asList(0.1f, 0.2f, 4f);
// algorithm to determine if the value in list1 > value in list 2
List<Boolean> result = listCombiner(list1, list2, (a, b) -> a > b);
assertThat(result).containsExactly(true, true, false);
}
@Test
public void givenTwoLists_whenComparedWithCombiningFunctionByMethodReference() {
List<Double> list1 = Arrays.asList(1.0d, 2.1d, 3.3d);
List<Float> list2 = Arrays.asList(0.1f, 0.2f, 4f);
// algorithm to determine if the value in list1 > value in list 2
List<Boolean> result = listCombiner(list1, list2, this::firstIsGreaterThanSecond);
assertThat(result).containsExactly(true, true, false);
}
private boolean firstIsGreaterThanSecond(Double a, Float b) {
return a > b;
}
@Test
public void givenTwoLists_whenComparedForEqualityByCombiningFunction() {
List<Float> list1 = Arrays.asList(0.1f, 0.2f, 4f);
List<Float> list2 = Arrays.asList(0.1f, 0.2f, 4f);
List<Boolean> result = listCombiner(list1, list2, (a, b) -> a.equals(b));
assertThat(result).containsExactly(true, true, true);
}
@Test
public void givenTwoLists_whenComparedForEqualityByCombiningFunctionWithMethodReference() {
List<Float> list1 = Arrays.asList(0.1f, 0.2f, 4f);
List<Float> list2 = Arrays.asList(0.1f, 0.2f, 4f);
List<Boolean> result = listCombiner(list1, list2, Float::equals);
assertThat(result).containsExactly(true, true, true);
}
@Test
public void givenTwoLists_whenComparedWithCombiningFunctionWithCompareTo() {
List<Double> list1 = Arrays.asList(1.0d, 2.1d, 3.3d);
List<Double> list2 = Arrays.asList(0.1d, 0.2d, 4d);
List<Integer> result = listCombiner(list1, list2, Double::compareTo);
assertThat(result).containsExactly(1, 1, -1);
}
/**
* Allows you to to pass in a lambda or method reference and then
* get access to the BiFunction it is meant to become
*/
private static <T, U, R> BiFunction<T, U, R> asBiFunction(BiFunction<T, U, R> function) {
return function;
}
@Test
public void givenTwoLists_whenComparedWithCombiningFunctionWithComposedBiFunction() {
List<Double> list1 = Arrays.asList(1.0d, 2.1d, 3.3d);
List<Double> list2 = Arrays.asList(0.1d, 0.2d, 4d);
List<Boolean> result = listCombiner(list1, list2,
asBiFunction(Double::compareTo)
.andThen(i -> i > 0));
assertThat(result).containsExactly(true, true, false);
}
}
+1 -1
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@@ -389,7 +389,7 @@
<properties>
<!-- util -->
<commons-lang3.version>3.8.1</commons-lang3.version>
<commons-lang3.version>3.9</commons-lang3.version>
<jmh-core.version>1.19</jmh-core.version>
<jmh-generator-annprocess.version>1.19</jmh-generator-annprocess.version>
@@ -1,49 +0,0 @@
package com.baeldung.array;
import java.util.Arrays;
import java.util.Scanner;
public class JaggedArray {
int[][] shortHandFormInitialization() {
int[][] jaggedArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
return jaggedArr;
}
int[][] declarationAndThenInitialization() {
int[][] jaggedArr = new int[3][];
jaggedArr[0] = new int[] { 1, 2 };
jaggedArr[1] = new int[] { 3, 4, 5 };
jaggedArr[2] = new int[] { 6, 7, 8, 9 };
return jaggedArr;
}
int[][] declarationAndThenInitializationUsingUserInputs() {
int[][] jaggedArr = new int[3][];
jaggedArr[0] = new int[2];
jaggedArr[1] = new int[3];
jaggedArr[2] = new int[4];
initializeElements(jaggedArr);
return jaggedArr;
}
void initializeElements(int[][] jaggedArr) {
Scanner sc = new Scanner(System.in);
for (int outer = 0; outer < jaggedArr.length; outer++) {
for (int inner = 0; inner < jaggedArr[outer].length; inner++) {
jaggedArr[outer][inner] = sc.nextInt();
}
}
}
void printElements(int[][] jaggedArr) {
for (int index = 0; index < jaggedArr.length; index++) {
System.out.println(Arrays.toString(jaggedArr[index]));
}
}
int[] getElementAtGivenIndex(int[][] jaggedArr, int index) {
return jaggedArr[index];
}
}
@@ -0,0 +1,83 @@
package com.baeldung.array;
import java.util.Arrays;
import java.util.Scanner;
public class MultiDimensionalArray {
int[][] shortHandFormInitialization() {
int[][] multiDimensionalArray = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
return multiDimensionalArray;
}
int[][] declarationAndThenInitialization() {
int[][] multiDimensionalArray = new int[3][];
multiDimensionalArray[0] = new int[] { 1, 2 };
multiDimensionalArray[1] = new int[] { 3, 4, 5 };
multiDimensionalArray[2] = new int[] { 6, 7, 8, 9 };
return multiDimensionalArray;
}
int[][] declarationAndThenInitializationUsingUserInputs() {
int[][] multiDimensionalArray = new int[3][];
multiDimensionalArray[0] = new int[2];
multiDimensionalArray[1] = new int[3];
multiDimensionalArray[2] = new int[4];
initializeElements(multiDimensionalArray);
return multiDimensionalArray;
}
void initializeElements(int[][] multiDimensionalArray) {
Scanner sc = new Scanner(System.in);
for (int outer = 0; outer < multiDimensionalArray.length; outer++) {
for (int inner = 0; inner < multiDimensionalArray[outer].length; inner++) {
multiDimensionalArray[outer][inner] = sc.nextInt();
}
}
}
void initialize2DArray(int[][] multiDimensionalArray) {
for (int[] array : multiDimensionalArray) {
Arrays.fill(array, 7);
}
}
void printElements(int[][] multiDimensionalArray) {
for (int index = 0; index < multiDimensionalArray.length; index++) {
System.out.println(Arrays.toString(multiDimensionalArray[index]));
}
}
int[] getElementAtGivenIndex(int[][] multiDimensionalArray, int index) {
return multiDimensionalArray[index];
}
int[] findLengthOfElements(int[][] multiDimensionalArray) {
int[] arrayOfLengths = new int[multiDimensionalArray.length];
for (int i = 0; i < multiDimensionalArray.length; i++) {
arrayOfLengths[i] = multiDimensionalArray[i].length;
}
return arrayOfLengths;
}
Integer[] findLengthOfElements(Integer[][] multiDimensionalArray) {
return Arrays.stream(multiDimensionalArray)
.map(array -> array.length)
.toArray(Integer[]::new);
}
int[][] copy2DArray(int[][] arrayOfArrays) {
int[][] copied2DArray = new int[arrayOfArrays.length][];
for (int i = 0; i < arrayOfArrays.length; i++) {
int[] array = arrayOfArrays[i];
copied2DArray[i] = Arrays.copyOf(array, array.length);
}
return copied2DArray;
}
Integer[][] copy2DArray(Integer[][] arrayOfArrays) {
return Arrays.stream(arrayOfArrays)
.map(array -> Arrays.copyOf(array, array.length))
.toArray(Integer[][]::new);
}
}
@@ -0,0 +1,27 @@
package com.baeldung.array;
import org.apache.commons.lang3.ArrayUtils;
public class RemoveElementFromAnArray {
public int[] removeAnElementWithAGivenIndex(int[] array, int index) {
return ArrayUtils.remove(array, index);
}
public int[] removeAllElementsWithGivenIndices(int[] array, int... indicies) {
return ArrayUtils.removeAll(array, indicies);
}
public int[] removeFirstOccurrenceOfGivenElement(int[] array, int element) {
return ArrayUtils.removeElement(array, element);
}
public int[] removeAllGivenElements(int[] array, int... elements) {
return ArrayUtils.removeElements(array, elements);
}
public int[] removeAllOccurrencesOfAGivenElement(int[] array, int element) {
return ArrayUtils.removeAllOccurences(array, element);
}
}
@@ -1,53 +0,0 @@
package com.baeldung.array;
import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.PrintStream;
import org.junit.Test;
public class JaggedArrayUnitTest {
private JaggedArray obj = new JaggedArray();
@Test
public void whenInitializedUsingShortHandForm_thenCorrect() {
assertArrayEquals(new int[][] { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } }, obj.shortHandFormInitialization());
}
@Test
public void whenInitializedWithDeclarationAndThenInitalization_thenCorrect() {
assertArrayEquals(new int[][] { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } }, obj.declarationAndThenInitialization());
}
@Test
public void whenInitializedWithDeclarationAndThenInitalizationUsingUserInputs_thenCorrect() {
InputStream is = new ByteArrayInputStream("1 2 3 4 5 6 7 8 9".getBytes());
System.setIn(is);
assertArrayEquals(new int[][] { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } }, obj.declarationAndThenInitializationUsingUserInputs());
System.setIn(System.in);
}
@Test
public void givenJaggedArrayAndAnIndex_thenReturnArrayAtGivenIndex() {
int[][] jaggedArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
assertArrayEquals(new int[] { 1, 2 }, obj.getElementAtGivenIndex(jaggedArr, 0));
assertArrayEquals(new int[] { 3, 4, 5 }, obj.getElementAtGivenIndex(jaggedArr, 1));
assertArrayEquals(new int[] { 6, 7, 8, 9 }, obj.getElementAtGivenIndex(jaggedArr, 2));
}
@Test
public void givenJaggedArray_whenUsingArraysAPI_thenVerifyPrintedElements() {
int[][] jaggedArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
ByteArrayOutputStream outContent = new ByteArrayOutputStream();
System.setOut(new PrintStream(outContent));
obj.printElements(jaggedArr);
assertEquals("[1, 2][3, 4, 5][6, 7, 8, 9]", outContent.toString().replace("\r", "").replace("\n", ""));
System.setOut(System.out);
}
}
@@ -0,0 +1,86 @@
package com.baeldung.array;
import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.PrintStream;
import org.junit.Test;
public class MultiDimensionalArrayUnitTest {
private MultiDimensionalArray obj = new MultiDimensionalArray();
@Test
public void whenInitializedUsingShortHandForm_thenCorrect() {
assertArrayEquals(new int[][] { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } }, obj.shortHandFormInitialization());
}
@Test
public void whenInitializedWithDeclarationAndThenInitalization_thenCorrect() {
assertArrayEquals(new int[][] { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } }, obj.declarationAndThenInitialization());
}
@Test
public void whenInitializedWithDeclarationAndThenInitalizationUsingUserInputs_thenCorrect() {
InputStream is = new ByteArrayInputStream("1 2 3 4 5 6 7 8 9".getBytes());
System.setIn(is);
assertArrayEquals(new int[][] { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } }, obj.declarationAndThenInitializationUsingUserInputs());
System.setIn(System.in);
}
@Test
public void givenMultiDimensionalArrayAndAnIndex_thenReturnArrayAtGivenIndex() {
int[][] multiDimensionalArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
assertArrayEquals(new int[] { 1, 2 }, obj.getElementAtGivenIndex(multiDimensionalArr, 0));
assertArrayEquals(new int[] { 3, 4, 5 }, obj.getElementAtGivenIndex(multiDimensionalArr, 1));
assertArrayEquals(new int[] { 6, 7, 8, 9 }, obj.getElementAtGivenIndex(multiDimensionalArr, 2));
}
@Test
public void givenMultiDimensionalArray_whenUsingArraysAPI_thenVerifyPrintedElements() {
int[][] multiDimensionalArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
ByteArrayOutputStream outContent = new ByteArrayOutputStream();
System.setOut(new PrintStream(outContent));
obj.printElements(multiDimensionalArr);
assertEquals("[1, 2][3, 4, 5][6, 7, 8, 9]", outContent.toString().replace("\r", "").replace("\n", ""));
System.setOut(System.out);
}
@Test
public void givenMultiDimensionalArray_whenUsingArraysFill_thenVerifyInitialize2DArray() {
int[][] multiDimensionalArr = new int[3][];
multiDimensionalArr[0] = new int[2];
multiDimensionalArr[1] = new int[3];
multiDimensionalArr[2] = new int[4];
obj.initialize2DArray(multiDimensionalArr);
assertArrayEquals(new int[][] {{7,7}, {7,7,7}, {7,7,7,7}}, multiDimensionalArr);
}
@Test
public void givenMultiDimensionalArray_whenUsingIteration_thenVerifyFindLengthOfElements() {
int[][] multiDimensionalArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
assertArrayEquals(new int[]{2,3,4}, obj.findLengthOfElements(multiDimensionalArr));
}
@Test
public void givenMultiDimensionalArray_whenUsingArraysStream_thenVerifyFindLengthOfElements() {
Integer[][] multiDimensionalArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
assertArrayEquals(new Integer[]{2,3,4}, obj.findLengthOfElements(multiDimensionalArr));
}
@Test
public void givenMultiDimensionalArray_whenUsingArraysCopyOf_thenVerifyCopy2DArray() {
int[][] multiDimensionalArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
assertArrayEquals(multiDimensionalArr, obj.copy2DArray(multiDimensionalArr));
}
@Test
public void givenMultiDimensionalArray_whenUsingArraysStream_thenVerifyCopy2DArray() {
Integer[][] multiDimensionalArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
assertArrayEquals(multiDimensionalArr, obj.copy2DArray(multiDimensionalArr));
}
}
@@ -0,0 +1,85 @@
package com.baeldung.array;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;
import org.apache.commons.lang3.ArrayUtils;
import org.junit.jupiter.api.Test;
class RemoveElementFromAnArrayUnitTest {
private final RemoveElementFromAnArray sut = new RemoveElementFromAnArray();
private final int[] inputArray = new int[] { 40, 10, 20, 30, 40, 50 };
@Test
void testRemoveAnElementWithAGivenIndex() {
int index = 2;
int[] modifiedArray = sut.removeAnElementWithAGivenIndex(inputArray, index);
assertFalse(ArrayUtils.contains(modifiedArray, inputArray[index]));
}
@Test
void testRemoveAllElementsWithGivenIndices() {
int first = 0;
int last = inputArray.length - 1;
int[] modifiedArray = sut.removeAllElementsWithGivenIndices(inputArray, first, last);
assertFalse(ArrayUtils.contains(modifiedArray, inputArray[first]) && ArrayUtils.contains(modifiedArray, inputArray[last]));
}
@Test
void testRemoveElement_WhenArrayIsNull_ThrowsIndexOutOfBoundEx() {
int index = 2;
assertThrows(IndexOutOfBoundsException.class, () -> {
sut.removeAnElementWithAGivenIndex(null, index);
});
assertThrows(IndexOutOfBoundsException.class, () -> {
sut.removeAllElementsWithGivenIndices(null, index);
});
}
@Test
void testRemoveFirstOccurrenceOfGivenElement() {
int element = 40;
int[] modifiedArray = sut.removeFirstOccurrenceOfGivenElement(inputArray, element);
int indexInInputArray = ArrayUtils.indexOf(inputArray, element);
int indexInModifiedArray = ArrayUtils.indexOf(modifiedArray, element);
assertFalse(indexInInputArray == indexInModifiedArray);
}
@Test
void testRemoveAllGivenElements() {
int duplicateElement = 40;
int[] elements = new int[] { duplicateElement, 10, 50 };
int[] modifiedArray = sut.removeAllGivenElements(inputArray, elements);
assertTrue(ArrayUtils.contains(modifiedArray, duplicateElement));
assertFalse(ArrayUtils.contains(modifiedArray, elements[1]));
assertFalse(ArrayUtils.contains(modifiedArray, elements[2]));
}
@Test
void testRemoveAllOccurrencesOfAGivenElement() {
int element = 40;
int[] modifiedArray = sut.removeAllOccurrencesOfAGivenElement(inputArray, element);
assertFalse(ArrayUtils.contains(modifiedArray, element));
}
@Test
void testRemoveElement_WhenArrayIsNull_ReturnsNull() {
int element = 20;
assertEquals(null, sut.removeFirstOccurrenceOfGivenElement(null, element));
assertEquals(null, sut.removeAllGivenElements(null, element));
assertEquals(null, sut.removeAllOccurrencesOfAGivenElement(null, element));
}
}
@@ -0,0 +1,36 @@
package com.baeldung.random;
import java.security.SecureRandom;
import java.security.NoSuchAlgorithmException;
import java.util.stream.IntStream;
import java.util.stream.LongStream;
import java.util.stream.DoubleStream;
public interface SecureRandomDemo {
public static void generateSecureRandomValues() {
SecureRandom sr = new SecureRandom();
int randomInt = sr.nextInt();
long randomLong = sr.nextLong();
float randomFloat = sr.nextFloat();
double randomDouble = sr.nextDouble();
boolean randomBoolean = sr.nextBoolean();
IntStream randomIntStream = sr.ints();
LongStream randomLongStream = sr.longs();
DoubleStream randomDoubleStream = sr.doubles();
byte[] values = new byte[124];
sr.nextBytes(values);
}
public static SecureRandom getSecureRandomForAlgorithm(String algorithm) throws NoSuchAlgorithmException {
if (algorithm == null || algorithm.isEmpty()) {
return new SecureRandom();
}
return SecureRandom.getInstance(algorithm);
}
}