Merge branch 'master' into thombergs-patch-7
This commit is contained in:
Tom Hombergs
GitHub
@@ -151,3 +151,9 @@
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- [Add a Character to a String at a Given Position](https://www.baeldung.com/java-add-character-to-string)
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- [Synthetic Constructs in Java](https://www.baeldung.com/java-synthetic)
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- [Calculating the nth Root in Java](https://www.baeldung.com/java-nth-root)
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- [Convert Double to String, Removing Decimal Places](https://www.baeldung.com/java-double-to-string)
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- [Different Ways to Capture Java Heap Dumps](https://www.baeldung.com/java-heap-dump-capture)
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- [How to Separate Double into Integer and Decimal Parts](https://www.baeldung.com/java-separate-double-into-integer-decimal-parts)
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- [ZoneOffset in Java](https://www.baeldung.com/java-zone-offset)
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- [Hashing a Password in Java](https://www.baeldung.com/java-password-hashing)
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- [Java Switch Statement](https://www.baeldung.com/java-switch)
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@@ -0,0 +1,159 @@
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package com.baeldung.array;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Comparator;
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import java.util.List;
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import java.util.stream.IntStream;
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import java.util.stream.Stream;
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public class ArrayReferenceGuide {
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public static void main(String[] args) {
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declaration();
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initialization();
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access();
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iterating();
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varargs();
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transformIntoList();
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transformIntoStream();
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sort();
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search();
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merge();
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}
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private static void declaration() {
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int[] anArray;
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int anotherArray[];
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}
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private static void initialization() {
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int[] anArray = new int[10];
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anArray[0] = 10;
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anArray[5] = 4;
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int[] anotherArray = new int[] {1, 2, 3, 4, 5};
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}
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private static void access() {
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int[] anArray = new int[10];
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anArray[0] = 10;
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anArray[5] = 4;
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System.out.println(anArray[0]);
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}
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private static void iterating() {
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int[] anArray = new int[] {1, 2, 3, 4, 5};
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for (int i = 0; i < anArray.length; i++) {
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System.out.println(anArray[i]);
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}
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for (int element : anArray) {
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System.out.println(element);
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}
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}
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private static void varargs() {
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String[] groceries = new String[] {"Milk", "Tomato", "Chips"};
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varargMethod(groceries);
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varargMethod("Milk", "Tomato", "Chips");
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}
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private static void varargMethod(String... varargs) {
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for (String element : varargs) {
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System.out.println(element);
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}
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}
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private static void transformIntoList() {
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Integer[] anArray = new Integer[] {1, 2, 3, 4, 5};
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// Naïve implementation
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List<Integer> aList = new ArrayList<>(); // We create an empty list
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for (int element : anArray) {
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// We iterate over array's elements and add them to the list
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aList.add(element);
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}
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// Pretty implementation
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aList = Arrays.asList(anArray);
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// Drawbacks
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try {
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aList.remove(0);
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} catch (UnsupportedOperationException e) {
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System.out.println(e.getMessage());
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}
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try {
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aList.add(6);
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} catch (UnsupportedOperationException e) {
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System.out.println(e.getMessage());
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}
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int[] anotherArray = new int[] {1, 2, 3, 4, 5};
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// List<Integer> anotherList = Arrays.asList(anotherArray);
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}
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private static void transformIntoStream() {
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int[] anArray = new int[] {1, 2, 3, 4, 5};
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IntStream aStream = Arrays.stream(anArray);
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Integer[] anotherArray = new Integer[] {1, 2, 3, 4, 5};
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Stream<Integer> anotherStream = Arrays.stream(anotherArray, 2, 4);
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}
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private static void sort() {
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int[] anArray = new int[] {5, 2, 1, 4, 8};
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Arrays.sort(anArray); // anArray is now {1, 2, 4, 5, 8}
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Integer[] anotherArray = new Integer[] {5, 2, 1, 4, 8};
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Arrays.sort(anotherArray); // anArray is now {1, 2, 4, 5, 8}
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String[] yetAnotherArray = new String[] {"A", "E", "Z", "B", "C"};
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Arrays.sort(yetAnotherArray, 1, 3, Comparator.comparing(String::toString).reversed()); // yetAnotherArray is now {"A", "Z", "E", "B", "C"}
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}
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private static void search() {
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int[] anArray = new int[] {5, 2, 1, 4, 8};
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for (int i = 0; i < anArray.length; i++) {
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if (anArray[i] == 4) {
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System.out.println("Found at index " + i);
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break;
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}
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}
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Arrays.sort(anArray);
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int index = Arrays.binarySearch(anArray, 4);
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System.out.println("Found at index " + index);
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}
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private static void merge() {
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int[] anArray = new int[] {5, 2, 1, 4, 8};
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int[] anotherArray = new int[] {10, 4, 9, 11, 2};
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int[] resultArray = new int[anArray.length + anotherArray.length];
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for (int i = 0; i < resultArray.length; i++) {
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resultArray[i] = (i < anArray.length ? anArray[i] : anotherArray[i - anArray.length]);
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}
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for (int element : resultArray) {
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System.out.println(element);
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}
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Arrays.setAll(resultArray, i -> (i < anArray.length ? anArray[i] : anotherArray[i - anArray.length]));
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for (int element : resultArray) {
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System.out.println(element);
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}
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}
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}
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@@ -1,11 +1,14 @@
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package com.baeldung.classloader;
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import java.io.*;
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import java.io.ByteArrayOutputStream;
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import java.io.File;
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import java.io.IOException;
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import java.io.InputStream;
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public class CustomClassLoader extends ClassLoader {
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public Class getClass(String name) throws ClassNotFoundException {
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@Override
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public Class findClass(String name) throws ClassNotFoundException {
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byte[] b = loadClassFromFile(name);
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return defineClass(name, b, 0, b.length);
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}
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@@ -1,15 +0,0 @@
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package com.baeldung.throwsexception;
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public class Calculator {
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public double divide(double a, double b) {
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if (b == 0) {
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throw new DivideByZeroException("Divider cannot be equal to zero!");
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}
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return a/b;
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}
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}
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@@ -1,9 +0,0 @@
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package com.baeldung.throwsexception;
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public class DivideByZeroException extends RuntimeException {
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public DivideByZeroException(String message) {
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super(message);
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}
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}
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@@ -11,7 +11,7 @@ public class CustomClassLoaderUnitTest {
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public void customLoader() throws ClassNotFoundException, IllegalAccessException, InstantiationException, NoSuchMethodException, InvocationTargetException {
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CustomClassLoader customClassLoader = new CustomClassLoader();
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Class<?> c = customClassLoader.getClass(PrintClassLoader.class.getName());
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Class<?> c = customClassLoader.findClass(PrintClassLoader.class.getName());
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Object ob = c.newInstance();
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@@ -1,22 +0,0 @@
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package com.baeldung.junit4vstestng;
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import static org.junit.Assert.assertTrue;
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import org.junit.FixMethodOrder;
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import org.junit.Test;
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import org.junit.runners.MethodSorters;
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@FixMethodOrder(MethodSorters.NAME_ASCENDING)
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public class SortedUnitTest {
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@Test
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public void a_givenString_whenChangedtoInt_thenTrue() {
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assertTrue(Integer.valueOf("10") instanceof Integer);
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}
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@Test
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public void b_givenInt_whenChangedtoString_thenTrue() {
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assertTrue(String.valueOf(10) instanceof String);
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}
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}
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@@ -1,58 +0,0 @@
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package com.baeldung.junit4vstestng;
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import org.junit.After;
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import org.junit.AfterClass;
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import org.junit.Assert;
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import org.junit.Before;
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import org.junit.BeforeClass;
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import org.junit.Ignore;
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import org.junit.Test;
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import java.util.ArrayList;
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import java.util.List;
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public class SummationServiceIntegrationTest {
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private static List<Integer> numbers;
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@BeforeClass
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public static void initialize() {
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numbers = new ArrayList<>();
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}
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@AfterClass
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public static void tearDown() {
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numbers = null;
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}
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@Before
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public void runBeforeEachTest() {
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numbers.add(1);
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numbers.add(2);
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numbers.add(3);
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}
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@After
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public void runAfterEachTest() {
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numbers.clear();
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}
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@Test
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public void givenNumbers_sumEquals_thenCorrect() {
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int sum = numbers.stream()
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.reduce(0, Integer::sum);
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Assert.assertEquals(6, sum);
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}
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@Ignore
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@Test
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public void givenEmptyList_sumEqualsZero_thenCorrect() {
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int sum = numbers.stream()
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.reduce(0, Integer::sum);
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Assert.assertEquals(6, sum);
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}
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@Test(expected = ArithmeticException.class)
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public void givenNumber_whenThrowsException_thenCorrect() {
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int i = 1 / 0;
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}
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}
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@@ -0,0 +1,54 @@
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package com.baeldung.modulo;
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import org.junit.Test;
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import static org.assertj.core.api.Java6Assertions.*;
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public class ModuloUnitTest {
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@Test
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public void whenIntegerDivision_thenLosesRemainder(){
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assertThat(11 / 4).isEqualTo(2);
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}
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@Test
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public void whenDoubleDivision_thenKeepsRemainder(){
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assertThat(11 / 4.0).isEqualTo(2.75);
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}
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@Test
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public void whenModulo_thenReturnsRemainder(){
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assertThat(11 % 4).isEqualTo(3);
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}
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@Test(expected = ArithmeticException.class)
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public void whenDivisionByZero_thenArithmeticException(){
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double result = 1 / 0;
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}
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@Test(expected = ArithmeticException.class)
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public void whenModuloByZero_thenArithmeticException(){
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double result = 1 % 0;
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}
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@Test
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public void whenDivisorIsOddAndModulusIs2_thenResultIs1(){
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assertThat(3 % 2).isEqualTo(1);
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}
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@Test
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public void whenDivisorIsEvenAndModulusIs2_thenResultIs0(){
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assertThat(4 % 2).isEqualTo(0);
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}
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@Test
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public void whenItemsIsAddedToCircularQueue_thenNoArrayIndexOutOfBounds(){
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int QUEUE_CAPACITY= 10;
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int[] circularQueue = new int[QUEUE_CAPACITY];
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int itemsInserted = 0;
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for (int value = 0; value < 1000; value++) {
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int writeIndex = ++itemsInserted % QUEUE_CAPACITY;
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circularQueue[writeIndex] = value;
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}
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}
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}
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@@ -1,11 +1,11 @@
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package com.baeldung.nth.root.calculator;
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import static org.junit.Assert.assertEquals;
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import org.junit.Test;
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import org.junit.runner.RunWith;
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import org.mockito.InjectMocks;
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import org.mockito.runners.MockitoJUnitRunner;
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import static org.junit.Assert.assertEquals;
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import org.mockito.junit.MockitoJUnitRunner;
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@RunWith(MockitoJUnitRunner.class)
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public class NthRootCalculatorUnitTest {
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@@ -1,17 +0,0 @@
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package com.baeldung.throwsexception;
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import org.junit.Test;
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import static org.junit.jupiter.api.Assertions.assertThrows;
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public class CalculatorUnitTest {
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@Test
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public void whenDividerIsZero_thenDivideByZeroExceptionIsThrown() {
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Calculator calculator = new Calculator();
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assertThrows(DivideByZeroException.class,
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() -> calculator.divide(10, 0));
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}
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}
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Reference in New Issue
Block a user