list = new ArrayList<>();
+
+ public void populateList() {
+ for (int i = 0; i < 10000000; i++) {
+ list.add(Math.random());
+ }
+ System.out.println("Debug Point 2");
+ }
+
+ public static void main(String[] args) {
+ System.out.println("Debug Point 1");
+ new StaticFieldsDemo().populateList();
+ System.out.println("Debug Point 3");
+ }
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/nth/root/calculator/NthRootCalculator.java b/core-java/src/main/java/com/baeldung/nth/root/calculator/NthRootCalculator.java
new file mode 100644
index 0000000000..217f1e06de
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/nth/root/calculator/NthRootCalculator.java
@@ -0,0 +1,8 @@
+package com.baeldung.nth.root.calculator;
+
+public class NthRootCalculator
+{
+ public Double calculate(Double base, Double n) {
+ return Math.pow(Math.E, Math.log(base)/n);
+ }
+}
diff --git a/core-java/src/main/java/com/baeldung/nth/root/main/Main.java b/core-java/src/main/java/com/baeldung/nth/root/main/Main.java
new file mode 100644
index 0000000000..3fcd36812f
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/nth/root/main/Main.java
@@ -0,0 +1,13 @@
+package com.baeldung.nth.root.main;
+
+import com.baeldung.nth.root.calculator.NthRootCalculator;
+
+public class Main {
+ public static void main(String[] args) {
+ NthRootCalculator calculator = new NthRootCalculator();
+ Double base = Double.parseDouble(args[0]);
+ Double n = Double.parseDouble(args[1]);
+ Double result = calculator.calculate(base, n);
+ System.out.println("The " + n + " root of " + base + " equals to " + result + ".");
+ }
+}
diff --git a/core-java/src/main/java/com/baeldung/passwordhashing/PBKDF2Hasher.java b/core-java/src/main/java/com/baeldung/passwordhashing/PBKDF2Hasher.java
new file mode 100644
index 0000000000..e2259e4249
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/passwordhashing/PBKDF2Hasher.java
@@ -0,0 +1,149 @@
+package com.baeldung.passwordhashing;
+
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.KeySpec;
+import java.util.Arrays;
+import java.util.Base64;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import javax.crypto.SecretKeyFactory;
+import javax.crypto.spec.PBEKeySpec;
+
+/**
+ * Hash passwords for storage, and test passwords against password tokens.
+ *
+ * Instances of this class can be used concurrently by multiple threads.
+ *
+ * @author erickson
+ * @see StackOverflow
+ */
+public final class PBKDF2Hasher
+{
+
+ /**
+ * Each token produced by this class uses this identifier as a prefix.
+ */
+ public static final String ID = "$31$";
+
+ /**
+ * The minimum recommended cost, used by default
+ */
+ public static final int DEFAULT_COST = 16;
+
+ private static final String ALGORITHM = "PBKDF2WithHmacSHA1";
+
+ private static final int SIZE = 128;
+
+ private static final Pattern layout = Pattern.compile("\\$31\\$(\\d\\d?)\\$(.{43})");
+
+ private final SecureRandom random;
+
+ private final int cost;
+
+ public PBKDF2Hasher()
+ {
+ this(DEFAULT_COST);
+ }
+
+ /**
+ * Create a password manager with a specified cost
+ *
+ * @param cost the exponential computational cost of hashing a password, 0 to 30
+ */
+ public PBKDF2Hasher(int cost)
+ {
+ iterations(cost); /* Validate cost */
+ this.cost = cost;
+ this.random = new SecureRandom();
+ }
+
+ private static int iterations(int cost)
+ {
+ if ((cost < 0) || (cost > 30))
+ throw new IllegalArgumentException("cost: " + cost);
+ return 1 << cost;
+ }
+
+ /**
+ * Hash a password for storage.
+ *
+ * @return a secure authentication token to be stored for later authentication
+ */
+ public String hash(char[] password)
+ {
+ byte[] salt = new byte[SIZE / 8];
+ random.nextBytes(salt);
+ byte[] dk = pbkdf2(password, salt, 1 << cost);
+ byte[] hash = new byte[salt.length + dk.length];
+ System.arraycopy(salt, 0, hash, 0, salt.length);
+ System.arraycopy(dk, 0, hash, salt.length, dk.length);
+ Base64.Encoder enc = Base64.getUrlEncoder().withoutPadding();
+ return ID + cost + '$' + enc.encodeToString(hash);
+ }
+
+ /**
+ * Authenticate with a password and a stored password token.
+ *
+ * @return true if the password and token match
+ */
+ public boolean checkPassword(char[] password, String token)
+ {
+ Matcher m = layout.matcher(token);
+ if (!m.matches())
+ throw new IllegalArgumentException("Invalid token format");
+ int iterations = iterations(Integer.parseInt(m.group(1)));
+ byte[] hash = Base64.getUrlDecoder().decode(m.group(2));
+ byte[] salt = Arrays.copyOfRange(hash, 0, SIZE / 8);
+ byte[] check = pbkdf2(password, salt, iterations);
+ int zero = 0;
+ for (int idx = 0; idx < check.length; ++idx)
+ zero |= hash[salt.length + idx] ^ check[idx];
+ return zero == 0;
+ }
+
+ private static byte[] pbkdf2(char[] password, byte[] salt, int iterations)
+ {
+ KeySpec spec = new PBEKeySpec(password, salt, iterations, SIZE);
+ try {
+ SecretKeyFactory f = SecretKeyFactory.getInstance(ALGORITHM);
+ return f.generateSecret(spec).getEncoded();
+ }
+ catch (NoSuchAlgorithmException ex) {
+ throw new IllegalStateException("Missing algorithm: " + ALGORITHM, ex);
+ }
+ catch (InvalidKeySpecException ex) {
+ throw new IllegalStateException("Invalid SecretKeyFactory", ex);
+ }
+ }
+
+ /**
+ * Hash a password in an immutable {@code String}.
+ *
+ * Passwords should be stored in a {@code char[]} so that it can be filled
+ * with zeros after use instead of lingering on the heap and elsewhere.
+ *
+ * @deprecated Use {@link #hash(char[])} instead
+ */
+ @Deprecated
+ public String hash(String password)
+ {
+ return hash(password.toCharArray());
+ }
+
+ /**
+ * Authenticate with a password in an immutable {@code String} and a stored
+ * password token.
+ *
+ * @deprecated Use {@link #checkPassword(char[],String)} instead.
+ * @see #hash(String)
+ */
+ @Deprecated
+ public boolean checkPassword(String password, String token)
+ {
+ return checkPassword(password.toCharArray(), token);
+ }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/passwordhashing/SHA512Hasher.java b/core-java/src/main/java/com/baeldung/passwordhashing/SHA512Hasher.java
new file mode 100644
index 0000000000..4f5337f963
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/passwordhashing/SHA512Hasher.java
@@ -0,0 +1,35 @@
+package com.baeldung.passwordhashing;
+
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+
+/** A really simple SHA_512 Encryption example.
+ *
+ */
+public class SHA512Hasher {
+
+ public String hash(String passwordToHash, byte[] salt){
+ String generatedPassword = null;
+ try {
+ MessageDigest md = MessageDigest.getInstance("SHA-512");
+ md.update(salt);
+ byte[] bytes = md.digest(passwordToHash.getBytes(StandardCharsets.UTF_8));
+ StringBuilder sb = new StringBuilder();
+ for(int i=0; i< bytes.length ;i++){
+ sb.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
+ }
+ generatedPassword = sb.toString();
+ }
+ catch (NoSuchAlgorithmException e){
+ e.printStackTrace();
+ }
+ return generatedPassword;
+ }
+
+ public boolean checkPassword(String hash, String attempt, byte[] salt){
+ String generatedHash = hash(attempt, salt);
+ return hash.equals(generatedHash);
+ }
+}
diff --git a/core-java/src/main/java/com/baeldung/passwordhashing/SimplePBKDF2Hasher.java b/core-java/src/main/java/com/baeldung/passwordhashing/SimplePBKDF2Hasher.java
new file mode 100644
index 0000000000..36c9b65070
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/passwordhashing/SimplePBKDF2Hasher.java
@@ -0,0 +1,18 @@
+package com.baeldung.passwordhashing;
+
+import javax.crypto.SecretKeyFactory;
+import javax.crypto.spec.PBEKeySpec;
+import java.security.spec.KeySpec;
+
+/** A really simple SimplePBKDF2 Encryption example.
+ *
+ */
+public class SimplePBKDF2Hasher {
+
+ public static String hashSimple(String password, byte[] salt) throws Exception{
+ KeySpec spec = new PBEKeySpec(password.toCharArray(), salt, 65536, 128);
+ SecretKeyFactory f = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
+ byte[] hash = f.generateSecret(spec).getEncoded();
+ return String.valueOf(hash);
+ }
+}
diff --git a/core-java/src/main/java/com/baeldung/string/AppendCharAtPositionX.java b/core-java/src/main/java/com/baeldung/string/AppendCharAtPositionX.java
new file mode 100644
index 0000000000..bebffe52f1
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/string/AppendCharAtPositionX.java
@@ -0,0 +1,45 @@
+/**
+ *
+ */
+package com.baeldung.string;
+
+/**
+ * @author swpraman
+ *
+ */
+public class AppendCharAtPositionX {
+
+ public String addCharUsingCharArray(String str, char ch, int position) {
+ validate(str, position);
+ int len = str.length();
+ char[] updatedArr = new char[len + 1];
+ str.getChars(0, position, updatedArr, 0);
+ updatedArr[position] = ch;
+ str.getChars(position, len, updatedArr, position + 1);
+ return new String(updatedArr);
+ }
+
+ public String addCharUsingSubstring(String str, char ch, int position) {
+ validate(str, position);
+ return str.substring(0, position) + ch + str.substring(position);
+ }
+
+ public String addCharUsingStringBuilder(String str, char ch, int position) {
+ validate(str, position);
+ StringBuilder sb = new StringBuilder(str);
+ sb.insert(position, ch);
+ return sb.toString();
+ }
+
+ private void validate(String str, int position) {
+ if (str == null) {
+ throw new IllegalArgumentException("Str should not be null");
+ }
+ int len = str.length();
+ if (position < 0 || position > len) {
+ throw new IllegalArgumentException("position[" + position + "] should be "
+ + "in the range 0.." + len + " for string " + str);
+ }
+ }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/switchstatement/SwitchStatement.java b/core-java/src/main/java/com/baeldung/switchstatement/SwitchStatement.java
new file mode 100644
index 0000000000..69e151bfcb
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/switchstatement/SwitchStatement.java
@@ -0,0 +1,70 @@
+package com.baeldung.switchstatement;
+
+public class SwitchStatement {
+
+ public String exampleOfIF(String animal) {
+
+ String result;
+
+ if (animal.equals("DOG") || animal.equals("CAT")) {
+ result = "domestic animal";
+ } else if (animal.equals("TIGER")) {
+ result = "wild animal";
+ } else {
+ result = "unknown animal";
+ }
+ return result;
+ }
+
+ public String exampleOfSwitch(String animal) {
+
+ String result;
+
+ switch (animal) {
+ case "DOG":
+ case "CAT":
+ result = "domestic animal";
+ break;
+ case "TIGER":
+ result = "wild animal";
+ break;
+ default:
+ result = "unknown animal";
+ break;
+ }
+ return result;
+ }
+
+ public String forgetBreakInSwitch(String animal) {
+
+ String result;
+
+ switch (animal) {
+
+ case "DOG":
+ System.out.println("domestic animal");
+ result = "domestic animal";
+
+ default:
+ System.out.println("unknown animal");
+ result = "unknown animal";
+
+ }
+ return result;
+ }
+
+ public String constantCaseValue(String animal) {
+
+ String result = "";
+
+ final String dog = "DOG";
+
+ switch (animal) {
+
+ case dog:
+ result = "domestic animal";
+ }
+ return result;
+ }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/synthetic/BridgeMethodDemo.java b/core-java/src/main/java/com/baeldung/synthetic/BridgeMethodDemo.java
new file mode 100644
index 0000000000..bdf6684f78
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/synthetic/BridgeMethodDemo.java
@@ -0,0 +1,23 @@
+package com.baeldung.synthetic;
+
+import java.util.Comparator;
+
+/**
+ * Class which contains a synthetic bridge method.
+ *
+ * @author Donato Rimenti
+ *
+ */
+public class BridgeMethodDemo implements Comparator {
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
+ */
+ @Override
+ public int compare(Integer o1, Integer o2) {
+ return 0;
+ }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/synthetic/SyntheticConstructorDemo.java b/core-java/src/main/java/com/baeldung/synthetic/SyntheticConstructorDemo.java
new file mode 100644
index 0000000000..d3d75ac05e
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/synthetic/SyntheticConstructorDemo.java
@@ -0,0 +1,34 @@
+package com.baeldung.synthetic;
+
+/**
+ * Wrapper for a class which contains a synthetic constructor.
+ *
+ * @author Donato Rimenti
+ *
+ */
+public class SyntheticConstructorDemo {
+
+ /**
+ * We need to instantiate the {@link NestedClass} using a private
+ * constructor from the enclosing instance in order to generate a synthetic
+ * constructor.
+ */
+ private NestedClass nestedClass = new NestedClass();
+
+ /**
+ * Class which contains a synthetic constructor.
+ *
+ * @author Donato Rimenti
+ *
+ */
+ class NestedClass {
+
+ /**
+ * In order to generate a synthetic constructor, this class must have a
+ * private constructor.
+ */
+ private NestedClass() {
+ }
+ }
+
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/synthetic/SyntheticFieldDemo.java b/core-java/src/main/java/com/baeldung/synthetic/SyntheticFieldDemo.java
new file mode 100644
index 0000000000..1813e03953
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/synthetic/SyntheticFieldDemo.java
@@ -0,0 +1,22 @@
+package com.baeldung.synthetic;
+
+/**
+ * Wrapper for a class which contains a synthetic field reference to the outer
+ * class.
+ *
+ * @author Donato Rimenti
+ *
+ */
+public class SyntheticFieldDemo {
+
+ /**
+ * Class which contains a synthetic field reference to the outer class.
+ *
+ * @author Donato Rimenti
+ *
+ */
+ class NestedClass {
+
+ }
+
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/synthetic/SyntheticMethodDemo.java b/core-java/src/main/java/com/baeldung/synthetic/SyntheticMethodDemo.java
new file mode 100644
index 0000000000..59be4e1429
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/synthetic/SyntheticMethodDemo.java
@@ -0,0 +1,48 @@
+package com.baeldung.synthetic;
+
+/**
+ * Wrapper for a class which contains two synthetic methods accessors to a
+ * private field.
+ *
+ * @author Donato Rimenti
+ *
+ */
+public class SyntheticMethodDemo {
+
+ /**
+ * Class which contains two synthetic methods accessors to a private field.
+ *
+ * @author Donato Rimenti
+ *
+ */
+ class NestedClass {
+
+ /**
+ * Field for which will be generated synthetic methods accessors. It's
+ * important that this field is private for this purpose.
+ */
+ private String nestedField;
+ }
+
+ /**
+ * Gets the private nested field. We need to read the nested field in order
+ * to generate the synthetic getter.
+ *
+ * @return the {@link NestedClass#nestedField}
+ */
+ public String getNestedField() {
+ return new NestedClass().nestedField;
+ }
+
+ /**
+ * Sets the private nested field. We need to write the nested field in order
+ * to generate the synthetic setter.
+ *
+ * @param nestedField
+ * the {@link NestedClass#nestedField}
+ */
+ public void setNestedField(String nestedField) {
+ new NestedClass().nestedField = nestedField;
+ }
+
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/zoneddatetime/OffsetDateTimeExample.java b/core-java/src/main/java/com/baeldung/zoneddatetime/OffsetDateTimeExample.java
new file mode 100644
index 0000000000..fb92eb8d0d
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/zoneddatetime/OffsetDateTimeExample.java
@@ -0,0 +1,13 @@
+package com.baeldung.zoneddatetime;
+
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+
+public class OffsetDateTimeExample {
+
+ public OffsetDateTime getCurrentTimeByZoneOffset(String offset) {
+ ZoneOffset zoneOffSet= ZoneOffset.of(offset);
+ OffsetDateTime date = OffsetDateTime.now(zoneOffSet);
+ return date;
+ }
+}
diff --git a/core-java/src/main/java/com/baeldung/zoneddatetime/OffsetTimeExample.java b/core-java/src/main/java/com/baeldung/zoneddatetime/OffsetTimeExample.java
new file mode 100644
index 0000000000..58e2d4d5ad
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/zoneddatetime/OffsetTimeExample.java
@@ -0,0 +1,13 @@
+package com.baeldung.zoneddatetime;
+
+import java.time.OffsetTime;
+import java.time.ZoneOffset;
+
+public class OffsetTimeExample {
+
+ public OffsetTime getCurrentTimeByZoneOffset(String offset) {
+ ZoneOffset zoneOffSet = ZoneOffset.of(offset);
+ OffsetTime time = OffsetTime.now(zoneOffSet);
+ return time;
+ }
+}
diff --git a/core-java/src/main/java/com/baeldung/zoneddatetime/ZoneDateTimeExample.java b/core-java/src/main/java/com/baeldung/zoneddatetime/ZoneDateTimeExample.java
new file mode 100644
index 0000000000..b54b8c5225
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/zoneddatetime/ZoneDateTimeExample.java
@@ -0,0 +1,21 @@
+package com.baeldung.zoneddatetime;
+
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+
+public class ZoneDateTimeExample {
+
+ public ZonedDateTime getCurrentTimeByZoneId(String region) {
+ ZoneId zone = ZoneId.of(region);
+ ZonedDateTime date = ZonedDateTime.now(zone);
+ return date;
+ }
+
+ public ZonedDateTime convertZonedDateTime(ZonedDateTime sourceDate, String destZone) {
+
+ ZoneId destZoneId = ZoneId.of(destZone);
+ ZonedDateTime destDate = sourceDate.withZoneSameInstant(destZoneId);
+
+ return destDate;
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/memoryleaks/equalshashcode/PersonMemoryLeakUnitTest.java b/core-java/src/test/java/com/baeldung/memoryleaks/equalshashcode/PersonMemoryLeakUnitTest.java
new file mode 100644
index 0000000000..3fa1db18d2
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/memoryleaks/equalshashcode/PersonMemoryLeakUnitTest.java
@@ -0,0 +1,33 @@
+package com.baeldung.memoryleaks.equalshashcode;
+
+import static org.junit.Assert.assertTrue;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class PersonMemoryLeakUnitTest {
+ @Test
+ @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+ public void givenMap_whenEqualsAndHashCodeNotOverridden_thenMemoryLeak() {
+ Map map = new HashMap();
+ for(int i=0; i<10000000; i++) {
+ map.put(new Person("jon"), 1);
+ }
+ assertTrue(map.size() > 1);
+ System.out.print("Debug Point - VisuaLVM");
+ }
+
+ @Test
+ @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+ public void givenMap_whenEqualsAndHashCodeOverridden_thenNoMemoryLeak() {
+ Map map = new HashMap();
+ for(int i=0; i<10000; i++) {
+ map.put(new PersonOptimized("jon"), 1);
+ }
+ assertTrue(map.size() == 1);
+ System.out.print("Debug Point - VisuaLVM");
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/memoryleaks/finalize/FinalizeMemoryLeakUnitTest.java b/core-java/src/test/java/com/baeldung/memoryleaks/finalize/FinalizeMemoryLeakUnitTest.java
new file mode 100644
index 0000000000..b6d81a8968
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/memoryleaks/finalize/FinalizeMemoryLeakUnitTest.java
@@ -0,0 +1,28 @@
+package com.baeldung.memoryleaks.finalize;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class FinalizeMemoryLeakUnitTest {
+ @Test
+ @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+ public void givenObjectWithFinalizer_whenCreatingAndDestroyingThisObject_thenMemoryLeak() {
+ BulkyObject[] stock = new BulkyObject[100000];
+
+ for(int i=0; i<100000; i++) {
+ stock[i] = new BulkyObject();
+ }
+ System.out.print("Debug Point - VisuaLVM");
+ }
+
+ @Test
+ @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+ public void givenObjectWithoutFinalizer_whenCreatingAndDestroyingThisObject_thenNoMemoryLeak() {
+ BulkyObjectOptimized[] stock = new BulkyObjectOptimized[100000];
+
+ for(int i=0; i<100000; i++) {
+ stock[i] = new BulkyObjectOptimized();
+ }
+ System.out.print("Debug Point - VisuaLVM");
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/memoryleaks/innerclass/StaticInnerClassMemoryLeakUnitTest.java b/core-java/src/test/java/com/baeldung/memoryleaks/innerclass/StaticInnerClassMemoryLeakUnitTest.java
new file mode 100644
index 0000000000..0854e4a38a
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/memoryleaks/innerclass/StaticInnerClassMemoryLeakUnitTest.java
@@ -0,0 +1,20 @@
+package com.baeldung.memoryleaks.innerclass;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class StaticInnerClassMemoryLeakUnitTest {
+ @Test
+ @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+ public void givenUsingInnerClass_whenInitializingInnerClass_thenInnerClassHoldsReferenceOfOuterObject() {
+ InnerClassWrapper.SimpleInnerClass simpleInnerClassObj = new InnerClassWrapper().new SimpleInnerClass();
+ System.out.print("Debug Point - VisuaLVM");
+ }
+
+ @Test
+ @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+ public void givenUsingStaticNestedClass_whenInitializingInnerClass_thenStaticNestedClassDoesntReferenceOuterObject() {
+ StaticNestedClassWrapper.StaticNestedClass staticNestedClassObj = new StaticNestedClassWrapper.StaticNestedClass();
+ System.out.print("Debug Point - VisuaLVM");
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/memoryleaks/internedstrings/StringInternMemoryLeakUnitTest.java b/core-java/src/test/java/com/baeldung/memoryleaks/internedstrings/StringInternMemoryLeakUnitTest.java
new file mode 100644
index 0000000000..6d363e0bdc
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/memoryleaks/internedstrings/StringInternMemoryLeakUnitTest.java
@@ -0,0 +1,20 @@
+package com.baeldung.memoryleaks.internedstrings;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class StringInternMemoryLeakUnitTest {
+ @Test
+ @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+ public void givenJava6OrBelow_whenInterningLargeStrings_thenPermgenIncreases() {
+ new InternedString().readString();
+ System.out.print("Debug Point - VisuaLVM");
+ }
+
+ @Test
+ @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+ public void givenJava6OrBelow_whenNotInterningLargeStrings_thenPermgenDoesntIncrease() {
+ new StringObject().readString();
+ System.out.print("Debug Point - VisuaLVM");
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/memoryleaks/staticfields/NonStaticFieldsMemoryLeakUnitTest.java b/core-java/src/test/java/com/baeldung/memoryleaks/staticfields/NonStaticFieldsMemoryLeakUnitTest.java
new file mode 100644
index 0000000000..e64fdb73e0
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/memoryleaks/staticfields/NonStaticFieldsMemoryLeakUnitTest.java
@@ -0,0 +1,26 @@
+package com.baeldung.memoryleaks.staticfields;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class NonStaticFieldsMemoryLeakUnitTest {
+ public List list = new ArrayList<>();
+
+ public void populateList() {
+ for (int i = 0; i < 10000000; i++) {
+ list.add(Math.random());
+ }
+ System.out.println("Debug Point 2");
+ }
+
+ @Test
+ @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+ public void givenNonStaticLargeList_whenPopulatingList_thenListGarbageCollected() {
+ System.out.println("Debug Point 1");
+ new NonStaticFieldsMemoryLeakUnitTest().populateList();
+ System.out.println("Debug Point 3");
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/memoryleaks/staticfields/StaticFieldsMemoryLeakUnitTest.java b/core-java/src/test/java/com/baeldung/memoryleaks/staticfields/StaticFieldsMemoryLeakUnitTest.java
new file mode 100644
index 0000000000..1765f0cf0d
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/memoryleaks/staticfields/StaticFieldsMemoryLeakUnitTest.java
@@ -0,0 +1,26 @@
+package com.baeldung.memoryleaks.staticfields;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class StaticFieldsMemoryLeakUnitTest {
+ public static List list = new ArrayList<>();
+
+ public void populateList() {
+ for (int i = 0; i < 10000000; i++) {
+ list.add(Math.random());
+ }
+ System.out.println("Debug Point 2");
+ }
+
+ @Test
+ @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+ public void givenStaticLargeList_whenPopulatingList_thenListIsNotGarbageCollected() {
+ System.out.println("Debug Point 1");
+ new StaticFieldsDemo().populateList();
+ System.out.println("Debug Point 3");
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/nth/root/calculator/NthRootCalculatorUnitTest.java b/core-java/src/test/java/com/baeldung/nth/root/calculator/NthRootCalculatorUnitTest.java
new file mode 100644
index 0000000000..388bceef49
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/nth/root/calculator/NthRootCalculatorUnitTest.java
@@ -0,0 +1,21 @@
+package com.baeldung.nth.root.calculator;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.runners.MockitoJUnitRunner;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(MockitoJUnitRunner.class)
+public class NthRootCalculatorUnitTest {
+
+ @InjectMocks
+ private NthRootCalculator nthRootCalculator;
+
+ @Test
+ public void giventThatTheBaseIs125_andTheExpIs3_whenCalculateIsCalled_thenTheResultIsTheCorrectOne() {
+ Double result = nthRootCalculator.calculate(125.0, 3.0);
+ assertEquals(result, (Double) 5.0d);
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/nth/root/main/MainUnitTest.java b/core-java/src/test/java/com/baeldung/nth/root/main/MainUnitTest.java
new file mode 100644
index 0000000000..a2fd839ba4
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/nth/root/main/MainUnitTest.java
@@ -0,0 +1,34 @@
+package com.baeldung.nth.root.main;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.InjectMocks;
+import static org.junit.Assert.assertEquals;
+
+public class MainUnitTest {
+ @InjectMocks
+ private Main main;
+
+ private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+ private final PrintStream originalOut = System.out;
+
+ @Before
+ public void setUpStreams() {
+ System.setOut(new PrintStream(outContent));
+ }
+
+ @After
+ public void restoreStreams() {
+ System.setOut(originalOut);
+ }
+
+ @Test
+ public void givenThatTheBaseIs125_andTheExpIs3_whenMainIsCalled_thenTheCorrectResultIsPrinted() {
+ main.main(new String[]{"125.0", "3.0"});
+ assertEquals("The 3.0 root of 125.0 equals to 5.0.\n", outContent.toString().replaceAll("\r", ""));
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/passwordhashing/PBKDF2HasherUnitTest.java b/core-java/src/test/java/com/baeldung/passwordhashing/PBKDF2HasherUnitTest.java
new file mode 100644
index 0000000000..8e90725c77
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/passwordhashing/PBKDF2HasherUnitTest.java
@@ -0,0 +1,41 @@
+package com.baeldung.passwordhashing;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+
+public class PBKDF2HasherUnitTest {
+
+ private PBKDF2Hasher mPBKDF2Hasher;
+
+ @Before
+ public void setUp() throws Exception {
+ mPBKDF2Hasher = new PBKDF2Hasher();
+ }
+
+ @Test
+ public void givenCorrectMessageAndHash_whenAuthenticated_checkAuthenticationSucceeds() throws Exception {
+ String message1 = "password123";
+
+ String hash1 = mPBKDF2Hasher.hash(message1.toCharArray());
+
+ assertTrue(mPBKDF2Hasher.checkPassword(message1.toCharArray(), hash1));
+
+ }
+
+ @Test
+ public void givenWrongMessage_whenAuthenticated_checkAuthenticationFails() throws Exception {
+ String message1 = "password123";
+
+ String hash1 = mPBKDF2Hasher.hash(message1.toCharArray());
+
+ String wrongPasswordAttempt = "IamWrong";
+
+ assertFalse(mPBKDF2Hasher.checkPassword(wrongPasswordAttempt.toCharArray(), hash1));
+
+ }
+
+
+}
\ No newline at end of file
diff --git a/core-java/src/test/java/com/baeldung/passwordhashing/SHA512HasherUnitTest.java b/core-java/src/test/java/com/baeldung/passwordhashing/SHA512HasherUnitTest.java
new file mode 100644
index 0000000000..3acfb0ba9d
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/passwordhashing/SHA512HasherUnitTest.java
@@ -0,0 +1,70 @@
+package com.baeldung.passwordhashing;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.security.SecureRandom;
+
+import static org.junit.Assert.*;
+
+/**
+ * Created by PhysicsSam on 06-Sep-18.
+ */
+public class SHA512HasherUnitTest {
+
+ private SHA512Hasher hasher;
+ private SecureRandom secureRandom;
+
+ @Before
+ public void setUp() throws Exception {
+ hasher = new SHA512Hasher();
+ secureRandom = new SecureRandom();
+ }
+
+ @Test
+ public void givenSamePasswordAndSalt_whenHashed_checkResultingHashesAreEqual() throws Exception {
+
+ byte[] salt = new byte[16];
+ secureRandom.nextBytes(salt);
+
+ String hash1 = hasher.hash("password", salt);
+ String hash2 = hasher.hash("password", salt);
+
+ assertEquals(hash1, hash2);
+
+ }
+
+ @Test
+ public void givenSamePasswordAndDifferentSalt_whenHashed_checkResultingHashesNotEqual() throws Exception {
+
+ byte[] salt = new byte[16];
+ secureRandom.nextBytes(salt);
+ String hash1 = hasher.hash("password", salt);
+ //generate a second salt
+ byte[] secondSalt = new byte[16];
+ String hash2 = hasher.hash("password", secondSalt);
+
+ assertNotEquals(hash1, hash2);
+
+ }
+
+ @Test
+ public void givenPredefinedHash_whenCorrectAttemptGiven_checkAuthenticationSucceeds() throws Exception {
+ byte[] salt = new byte[16];
+ secureRandom.nextBytes(salt);
+
+ String originalHash = hasher.hash("password123", salt);
+
+ assertTrue(hasher.checkPassword(originalHash, "password123", salt));
+ }
+
+ @Test
+ public void givenPredefinedHash_whenIncorrectAttemptGiven_checkAuthenticationFails() throws Exception {
+ byte[] salt = new byte[16];
+ secureRandom.nextBytes(salt);
+
+ String originalHash = hasher.hash("password123", salt);
+
+ assertFalse(hasher.checkPassword(originalHash, "password124", salt));
+ }
+}
\ No newline at end of file
diff --git a/core-java/src/test/java/com/baeldung/removingdecimals/RemovingDecimalsManualTest.java b/core-java/src/test/java/com/baeldung/removingdecimals/RemovingDecimalsManualTest.java
new file mode 100644
index 0000000000..8dbfcaf5e7
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/removingdecimals/RemovingDecimalsManualTest.java
@@ -0,0 +1,100 @@
+package com.baeldung.removingdecimals;
+
+import org.junit.Test;
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+import java.text.DecimalFormat;
+import java.text.NumberFormat;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * This benchmark compares some of the approaches to formatting a floating-point
+ * value into a {@link String} while removing the decimal part.
+ *
+ * To run, simply run the {@link RemovingDecimalsManualTest#runBenchmarks()} test
+ * at the end of this class.
+ *
+ * The benchmark takes about 15 minutes to run. Since it is using {@link Mode#Throughput},
+ * higher numbers mean better performance.
+ */
+@BenchmarkMode(Mode.Throughput)
+@Warmup(iterations = 5)
+@Measurement(iterations = 20)
+@OutputTimeUnit(TimeUnit.MICROSECONDS)
+@State(Scope.Benchmark)
+public class RemovingDecimalsManualTest {
+ @Param(value = {"345.56", "345345345.56", "345345345345345345.56"}) double doubleValue;
+
+ NumberFormat nf;
+ DecimalFormat df;
+
+ @Setup
+ public void readyFormatters() {
+ nf = NumberFormat.getInstance();
+ nf.setMaximumFractionDigits(0);
+ df = new DecimalFormat("#,###");
+ }
+
+ @Benchmark
+ public String whenCastToInt_thenValueIsTruncated() {
+ return String.valueOf((int) doubleValue);
+ }
+
+ @Benchmark
+ public String whenUsingStringFormat_thenValueIsRounded() {
+ return String.format("%.0f", doubleValue);
+ }
+
+ @Benchmark
+ public String whenUsingNumberFormat_thenValueIsRounded() {
+ nf.setRoundingMode(RoundingMode.HALF_UP);
+ return nf.format(doubleValue);
+ }
+
+ @Benchmark
+ public String whenUsingNumberFormatWithFloor_thenValueIsTruncated() {
+ nf.setRoundingMode(RoundingMode.FLOOR);
+ return nf.format(doubleValue);
+ }
+
+ @Benchmark
+ public String whenUsingDecimalFormat_thenValueIsRounded() {
+ df.setRoundingMode(RoundingMode.HALF_UP);
+ return df.format(doubleValue);
+ }
+
+ @Benchmark
+ public String whenUsingDecimalFormatWithFloor_thenValueIsTruncated() {
+ df.setRoundingMode(RoundingMode.FLOOR);
+ return df.format(doubleValue);
+ }
+
+ @Benchmark
+ public String whenUsingBigDecimalDoubleValue_thenValueIsTruncated() {
+ BigDecimal big = new BigDecimal(doubleValue);
+ big = big.setScale(0, RoundingMode.FLOOR);
+ return big.toString();
+ }
+
+ @Benchmark
+ public String whenUsingBigDecimalDoubleValueWithHalfUp_thenValueIsRounded() {
+ BigDecimal big = new BigDecimal(doubleValue);
+ big = big.setScale(0, RoundingMode.HALF_UP);
+ return big.toString();
+ }
+
+ @Test
+ public void runBenchmarks() throws Exception {
+ Options options = new OptionsBuilder()
+ .include(this.getClass().getSimpleName()).threads(1)
+ .forks(1).shouldFailOnError(true).shouldDoGC(true)
+ .jvmArgs("-server").build();
+
+ new Runner(options).run();
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/removingdecimals/RemovingDecimalsUnitTest.java b/core-java/src/test/java/com/baeldung/removingdecimals/RemovingDecimalsUnitTest.java
new file mode 100644
index 0000000000..2f634b553b
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/removingdecimals/RemovingDecimalsUnitTest.java
@@ -0,0 +1,95 @@
+package com.baeldung.removingdecimals;
+
+import org.junit.Test;
+
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+import java.text.DecimalFormat;
+import java.text.NumberFormat;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+/**
+ * Tests that demonstrate some different approaches for formatting a
+ * floating-point value into a {@link String} while removing the decimal part.
+ */
+public class RemovingDecimalsUnitTest {
+ private final double doubleValue = 345.56;
+
+ @Test
+ public void whenCastToInt_thenValueIsTruncated() {
+ String truncated = String.valueOf((int) doubleValue);
+ assertEquals("345", truncated);
+ }
+
+ @Test
+ public void givenALargeDouble_whenCastToInt_thenValueIsNotTruncated() {
+ double outOfIntRange = 6_000_000_000.56;
+ String truncationAttempt = String.valueOf((int) outOfIntRange);
+ assertNotEquals("6000000000", truncationAttempt);
+ }
+
+ @Test
+ public void whenUsingStringFormat_thenValueIsRounded() {
+ String rounded = String.format("%.0f", doubleValue);
+ assertEquals("346", rounded);
+ }
+
+ @Test
+ public void givenALargeDouble_whenUsingStringFormat_thenValueIsStillRounded() {
+ double outOfIntRange = 6_000_000_000.56;
+ String rounded = String.format("%.0f", outOfIntRange);
+ assertEquals("6000000001", rounded);
+ }
+
+ @Test
+ public void whenUsingNumberFormat_thenValueIsRounded() {
+ NumberFormat nf = NumberFormat.getInstance();
+ nf.setMaximumFractionDigits(0);
+ nf.setRoundingMode(RoundingMode.HALF_UP);
+ String rounded = nf.format(doubleValue);
+ assertEquals("346", rounded);
+ }
+
+ @Test
+ public void whenUsingNumberFormatWithFloor_thenValueIsTruncated() {
+ NumberFormat nf = NumberFormat.getInstance();
+ nf.setMaximumFractionDigits(0);
+ nf.setRoundingMode(RoundingMode.FLOOR);
+ String truncated = nf.format(doubleValue);
+ assertEquals("345", truncated);
+ }
+
+ @Test
+ public void whenUsingDecimalFormat_thenValueIsRounded() {
+ DecimalFormat df = new DecimalFormat("#,###");
+ df.setRoundingMode(RoundingMode.HALF_UP);
+ String rounded = df.format(doubleValue);
+ assertEquals("346", rounded);
+ }
+
+ @Test
+ public void whenUsingDecimalFormatWithFloor_thenValueIsTruncated() {
+ DecimalFormat df = new DecimalFormat("#,###");
+ df.setRoundingMode(RoundingMode.FLOOR);
+ String truncated = df.format(doubleValue);
+ assertEquals("345", truncated);
+ }
+
+ @Test
+ public void whenUsingBigDecimalDoubleValue_thenValueIsTruncated() {
+ BigDecimal big = new BigDecimal(doubleValue);
+ big = big.setScale(0, RoundingMode.FLOOR);
+ String truncated = big.toString();
+ assertEquals("345", truncated);
+ }
+
+ @Test
+ public void whenUsingBigDecimalDoubleValueWithHalfUp_thenValueIsRounded() {
+ BigDecimal big = new BigDecimal(doubleValue);
+ big = big.setScale(0, RoundingMode.HALF_UP);
+ String truncated = big.toString();
+ assertEquals("346", truncated);
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/string/AppendCharAtPositionXUnitTest.java b/core-java/src/test/java/com/baeldung/string/AppendCharAtPositionXUnitTest.java
new file mode 100644
index 0000000000..2cdf6145d3
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/string/AppendCharAtPositionXUnitTest.java
@@ -0,0 +1,110 @@
+/**
+ *
+ */
+package com.baeldung.string;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+/**
+ * @author swpraman
+ *
+ */
+public class AppendCharAtPositionXUnitTest {
+
+ private AppendCharAtPositionX appendCharAtPosition = new AppendCharAtPositionX();
+ private String word = "Titanc";
+ private char letter = 'i';
+
+ @Test
+ public void whenUsingCharacterArrayAndCharacterAddedAtBeginning_shouldAddCharacter() {
+ assertEquals("iTitanc", appendCharAtPosition.addCharUsingCharArray(word, letter, 0));
+ }
+
+ @Test
+ public void whenUsingSubstringAndCharacterAddedAtBeginning_shouldAddCharacter() {
+ assertEquals("iTitanc", appendCharAtPosition.addCharUsingSubstring(word, letter, 0));
+ }
+
+ @Test
+ public void whenUsingStringBuilderAndCharacterAddedAtBeginning_shouldAddCharacter() {
+ assertEquals("iTitanc", appendCharAtPosition.addCharUsingStringBuilder(word, letter, 0));
+ }
+
+ @Test
+ public void whenUsingCharacterArrayAndCharacterAddedAtMiddle_shouldAddCharacter() {
+ assertEquals("Titianc", appendCharAtPosition.addCharUsingCharArray(word, letter, 3));
+ }
+
+ @Test
+ public void whenUsingSubstringAndCharacterAddedAtMiddle_shouldAddCharacter() {
+ assertEquals("Titianc", appendCharAtPosition.addCharUsingSubstring(word, letter, 3));
+ }
+
+ @Test
+ public void whenUsingStringBuilderAndCharacterAddedAtMiddle_shouldAddCharacter() {
+ assertEquals("Titianc", appendCharAtPosition.addCharUsingStringBuilder(word, letter, 3));
+ }
+
+ @Test
+ public void whenUsingCharacterArrayAndCharacterAddedAtEnd_shouldAddCharacter() {
+ assertEquals("Titanci", appendCharAtPosition.addCharUsingCharArray(word, letter, word.length()));
+ }
+
+ @Test
+ public void whenUsingSubstringAndCharacterAddedAtEnd_shouldAddCharacter() {
+ assertEquals("Titanci", appendCharAtPosition.addCharUsingSubstring(word, letter, word.length()));
+ }
+
+ @Test
+ public void whenUsingStringBuilderAndCharacterAddedAtEnd_shouldAddCharacter() {
+ assertEquals("Titanci", appendCharAtPosition.addCharUsingStringBuilder(word, letter, word.length()));
+ }
+
+ @Test(expected=IllegalArgumentException.class)
+ public void whenUsingCharacterArrayAndCharacterAddedAtNegativePosition_shouldThrowException() {
+ appendCharAtPosition.addCharUsingStringBuilder(word, letter, -1);
+ }
+
+ @Test(expected=IllegalArgumentException.class)
+ public void whenUsingSubstringAndCharacterAddedAtNegativePosition_shouldThrowException() {
+ appendCharAtPosition.addCharUsingStringBuilder(word, letter, -1);
+ }
+
+ @Test(expected=IllegalArgumentException.class)
+ public void whenUsingStringBuilderAndCharacterAddedAtNegativePosition_shouldThrowException() {
+ appendCharAtPosition.addCharUsingStringBuilder(word, letter, -1);
+ }
+
+ @Test(expected=IllegalArgumentException.class)
+ public void whenUsingCharacterArrayAndCharacterAddedAtInvalidPosition_shouldThrowException() {
+ appendCharAtPosition.addCharUsingStringBuilder(word, letter, word.length() + 2);
+ }
+
+ @Test(expected=IllegalArgumentException.class)
+ public void whenUsingSubstringAndCharacterAddedAtInvalidPosition_shouldThrowException() {
+ appendCharAtPosition.addCharUsingStringBuilder(word, letter, word.length() + 2);
+ }
+
+ @Test(expected=IllegalArgumentException.class)
+ public void whenUsingStringBuilderAndCharacterAddedAtInvalidPosition_shouldThrowException() {
+ appendCharAtPosition.addCharUsingStringBuilder(word, letter, word.length() + 2);
+ }
+
+ @Test(expected=IllegalArgumentException.class)
+ public void whenUsingCharacterArrayAndCharacterAddedAtPositionXAndStringIsNull_shouldThrowException() {
+ appendCharAtPosition.addCharUsingStringBuilder(null, letter, 3);
+ }
+
+ @Test(expected=IllegalArgumentException.class)
+ public void whenUsingSubstringAndCharacterAddedAtPositionXAndStringIsNull_shouldThrowException() {
+ appendCharAtPosition.addCharUsingStringBuilder(null, letter, 3);
+ }
+
+ @Test(expected=IllegalArgumentException.class)
+ public void whenUsingStringBuilderAndCharacterAddedAtPositionXAndStringIsNull_shouldThrowException() {
+ appendCharAtPosition.addCharUsingStringBuilder(null, letter, 3);
+ }
+
+}
diff --git a/core-java/src/test/java/com/baeldung/switchstatement/SwitchStatementUnitTest.java b/core-java/src/test/java/com/baeldung/switchstatement/SwitchStatementUnitTest.java
new file mode 100644
index 0000000000..e8ac645531
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/switchstatement/SwitchStatementUnitTest.java
@@ -0,0 +1,38 @@
+package com.baeldung.switchstatement;
+
+import org.junit.Test;
+
+import org.junit.Assert;
+
+public class SwitchStatementUnitTest {
+ private SwitchStatement s = new SwitchStatement();
+
+
+ @Test
+ public void whenDog_thenDomesticAnimal() {
+
+ String animal = "DOG";
+ Assert.assertEquals("domestic animal", s.exampleOfSwitch(animal));
+ }
+
+ @Test
+ public void whenNoBreaks_thenGoThroughBlocks() {
+ String animal = "DOG";
+ Assert.assertEquals("unknown animal", s.forgetBreakInSwitch(animal));
+ }
+
+ @Test(expected=NullPointerException.class)
+ public void whenSwitchAgumentIsNull_thenNullPointerException() {
+ String animal = null;
+ Assert.assertEquals("domestic animal", s.exampleOfSwitch(animal));
+ }
+
+
+ @Test
+ public void whenCompareStrings_thenByEqual() {
+ String animal = new String("DOG");
+ Assert.assertEquals("domestic animal", s.exampleOfSwitch(animal));
+ }
+
+
+}
diff --git a/core-java/src/test/java/com/baeldung/synthetic/SyntheticUnitTest.java b/core-java/src/test/java/com/baeldung/synthetic/SyntheticUnitTest.java
new file mode 100644
index 0000000000..20f7647f48
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/synthetic/SyntheticUnitTest.java
@@ -0,0 +1,99 @@
+package com.baeldung.synthetic;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Unit test for {@link SyntheticFieldDemo}, {@link SyntheticMethodDemo},
+ * {@link SyntheticConstructorDemo} and {@link BridgeMethodDemo} classes.
+ *
+ * @author Donato Rimenti
+ *
+ */
+public class SyntheticUnitTest {
+
+ /**
+ * Tests that the {@link SyntheticMethodDemo.NestedClass} contains two synthetic
+ * methods.
+ */
+ @Test
+ public void givenSyntheticMethod_whenIsSinthetic_thenTrue() {
+ // Checks that the nested class contains exactly two synthetic methods.
+ Method[] methods = SyntheticMethodDemo.NestedClass.class.getDeclaredMethods();
+ Assert.assertEquals("This class should contain only two methods", 2, methods.length);
+
+ for (Method m : methods) {
+ System.out.println("Method: " + m.getName() + ", isSynthetic: " + m.isSynthetic());
+ Assert.assertTrue("All the methods of this class should be synthetic", m.isSynthetic());
+ }
+ }
+
+ /**
+ * Tests that {@link SyntheticConstructorDemo.NestedClass} contains a synthetic
+ * constructor.
+ */
+ @Test
+ public void givenSyntheticConstructor_whenIsSinthetic_thenTrue() {
+ // Checks that the nested class contains exactly a synthetic
+ // constructor.
+ int syntheticConstructors = 0;
+ Constructor[] constructors = SyntheticConstructorDemo.NestedClass.class.getDeclaredConstructors();
+ Assert.assertEquals("This class should contain only two constructors", 2, constructors.length);
+
+ for (Constructor c : constructors) {
+ System.out.println("Constructor: " + c.getName() + ", isSynthetic: " + c.isSynthetic());
+
+ // Counts the synthetic constructors.
+ if (c.isSynthetic()) {
+ syntheticConstructors++;
+ }
+ }
+
+ // Checks that there's exactly one synthetic constructor.
+ Assert.assertEquals(1, syntheticConstructors);
+ }
+
+ /**
+ * Tests that {@link SyntheticFieldDemo.NestedClass} contains a synthetic field.
+ */
+ @Test
+ public void givenSyntheticField_whenIsSinthetic_thenTrue() {
+ // This class should contain exactly one synthetic field.
+ Field[] fields = SyntheticFieldDemo.NestedClass.class.getDeclaredFields();
+ Assert.assertEquals("This class should contain only one field", 1, fields.length);
+
+ for (Field f : fields) {
+ System.out.println("Field: " + f.getName() + ", isSynthetic: " + f.isSynthetic());
+ Assert.assertTrue("All the fields of this class should be synthetic", f.isSynthetic());
+ }
+ }
+
+ /**
+ * Tests that {@link BridgeMethodDemo} contains a synthetic bridge method.
+ */
+ @Test
+ public void givenBridgeMethod_whenIsBridge_thenTrue() {
+ // This class should contain exactly one synthetic bridge method.
+ int syntheticMethods = 0;
+ Method[] methods = BridgeMethodDemo.class.getDeclaredMethods();
+ for (Method m : methods) {
+ System.out.println(
+ "Method: " + m.getName() + ", isSynthetic: " + m.isSynthetic() + ", isBridge: " + m.isBridge());
+
+ // Counts the synthetic methods and checks that they are also bridge
+ // methods.
+ if (m.isSynthetic()) {
+ syntheticMethods++;
+ Assert.assertTrue("The synthetic method in this class should also be a bridge method", m.isBridge());
+ }
+ }
+
+ // Checks that there's exactly one synthetic bridge method.
+ Assert.assertEquals("There should be exactly 1 synthetic bridge method in this class", 1, syntheticMethods);
+ }
+
+}
\ No newline at end of file
diff --git a/core-java/src/test/java/com/baeldung/ternaryoperator/TernaryOperatorUnitTest.java b/core-java/src/test/java/com/baeldung/ternaryoperator/TernaryOperatorUnitTest.java
new file mode 100644
index 0000000000..6b292ad8ab
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/ternaryoperator/TernaryOperatorUnitTest.java
@@ -0,0 +1,43 @@
+package com.baeldung.ternaryoperator;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import org.junit.Test;
+
+public class TernaryOperatorUnitTest {
+
+ @Test
+ public void givenACondition_whenUsingTernaryOperator_thenItEvaluatesConditionAndReturnsAValue() {
+ int number = 10;
+ String msg = number > 10 ? "Number is greater than 10" : "Number is less than or equal to 10";
+
+ assertThat(msg).isEqualTo("Number is less than or equal to 10");
+ }
+
+ @Test
+ public void givenATrueCondition_whenUsingTernaryOperator_thenOnlyExpression1IsEvaluated() {
+ int exp1 = 0, exp2 = 0;
+ int result = 12 > 10 ? ++exp1 : ++exp2;
+
+ assertThat(exp1).isEqualTo(1);
+ assertThat(exp2).isEqualTo(0);
+ assertThat(result).isEqualTo(1);
+ }
+
+ @Test
+ public void givenAFalseCondition_whenUsingTernaryOperator_thenOnlyExpression2IsEvaluated() {
+ int exp1 = 0, exp2 = 0;
+ int result = 8 > 10 ? ++exp1 : ++exp2;
+
+ assertThat(exp1).isEqualTo(0);
+ assertThat(exp2).isEqualTo(1);
+ assertThat(result).isEqualTo(1);
+ }
+
+ @Test
+ public void givenANestedCondition_whenUsingTernaryOperator_thenCorrectValueIsReturned() {
+ int number = 6;
+ String msg = number > 10 ? "Number is greater than 10" : number > 5 ? "Number is greater than 5" : "Number is less than or equal to 5";
+
+ assertThat(msg).isEqualTo("Number is greater than 5");
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/zoneddatetime/OffsetDateTimeExampleUnitTest.java b/core-java/src/test/java/com/baeldung/zoneddatetime/OffsetDateTimeExampleUnitTest.java
new file mode 100644
index 0000000000..a08d3737cd
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/zoneddatetime/OffsetDateTimeExampleUnitTest.java
@@ -0,0 +1,22 @@
+package com.baeldung.zoneddatetime;
+
+import static org.junit.Assert.assertTrue;
+
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+
+import org.junit.Test;
+
+public class OffsetDateTimeExampleUnitTest {
+
+ OffsetDateTimeExample offsetDateTimeExample = new OffsetDateTimeExample();
+
+ @Test
+ public void givenZoneOffset_whenGetCurrentTime_thenResultHasZone() {
+ String offset = "+02:00";
+ OffsetDateTime time = offsetDateTimeExample.getCurrentTimeByZoneOffset(offset);
+
+ assertTrue(time.getOffset()
+ .equals(ZoneOffset.of(offset)));
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/zoneddatetime/OffsetTimeExampleUnitTest.java b/core-java/src/test/java/com/baeldung/zoneddatetime/OffsetTimeExampleUnitTest.java
new file mode 100644
index 0000000000..488f934179
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/zoneddatetime/OffsetTimeExampleUnitTest.java
@@ -0,0 +1,22 @@
+package com.baeldung.zoneddatetime;
+
+import static org.junit.Assert.assertTrue;
+
+import java.time.OffsetTime;
+import java.time.ZoneOffset;
+
+import org.junit.Test;
+
+public class OffsetTimeExampleUnitTest {
+
+ OffsetTimeExample offsetTimeExample = new OffsetTimeExample();
+
+ @Test
+ public void givenZoneOffset_whenGetCurrentTime_thenResultHasZone() {
+ String offset = "+02:00";
+ OffsetTime time = offsetTimeExample.getCurrentTimeByZoneOffset(offset);
+
+ assertTrue(time.getOffset()
+ .equals(ZoneOffset.of(offset)));
+ }
+}
diff --git a/core-java/src/test/java/com/baeldung/zoneddatetime/ZoneDateTimeExampleUnitTest.java b/core-java/src/test/java/com/baeldung/zoneddatetime/ZoneDateTimeExampleUnitTest.java
new file mode 100644
index 0000000000..e78ff3e3fd
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/zoneddatetime/ZoneDateTimeExampleUnitTest.java
@@ -0,0 +1,33 @@
+package com.baeldung.zoneddatetime;
+
+import static org.junit.Assert.assertTrue;
+
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+
+import org.junit.Test;
+
+public class ZoneDateTimeExampleUnitTest {
+
+ ZoneDateTimeExample zoneDateTimeExample = new ZoneDateTimeExample();
+
+ @Test
+ public void givenZone_whenGetCurrentTime_thenResultHasZone() {
+ String zone = "Europe/Berlin";
+ ZonedDateTime time = zoneDateTimeExample.getCurrentTimeByZoneId(zone);
+
+ assertTrue(time.getZone()
+ .equals(ZoneId.of(zone)));
+ }
+
+ @Test
+ public void givenZones_whenConvertDateByZone_thenGetConstantDiff() {
+ String sourceZone = "Europe/Berlin";
+ String destZone = "Asia/Tokyo";
+ ZonedDateTime sourceDate = zoneDateTimeExample.getCurrentTimeByZoneId(sourceZone);
+ ZonedDateTime destDate = zoneDateTimeExample.convertZonedDateTime(sourceDate, destZone);
+
+ assertTrue(sourceDate.toInstant()
+ .compareTo(destDate.toInstant()) == 0);
+ }
+}
diff --git a/core-kotlin/README.md b/core-kotlin/README.md
index 734b2c08b3..7d8d5213d1 100644
--- a/core-kotlin/README.md
+++ b/core-kotlin/README.md
@@ -8,7 +8,6 @@
- [Generics in Kotlin](http://www.baeldung.com/kotlin-generics)
- [Introduction to Kotlin Coroutines](http://www.baeldung.com/kotlin-coroutines)
- [Destructuring Declarations in Kotlin](http://www.baeldung.com/kotlin-destructuring-declarations)
-- [Kotlin with Mockito](http://www.baeldung.com/kotlin-mockito)
- [Lazy Initialization in Kotlin](http://www.baeldung.com/kotlin-lazy-initialization)
- [Overview of Kotlin Collections API](http://www.baeldung.com/kotlin-collections-api)
- [Converting a List to Map in Kotlin](http://www.baeldung.com/kotlin-list-to-map)
@@ -19,8 +18,6 @@
- [Extension Methods in Kotlin](http://www.baeldung.com/kotlin-extension-methods)
- [Infix Functions in Kotlin](http://www.baeldung.com/kotlin-infix-functions)
- [Try-with-resources in Kotlin](http://www.baeldung.com/kotlin-try-with-resources)
-- [HTTP Requests with Kotlin and khttp](http://www.baeldung.com/kotlin-khttp)
-- [Kotlin Dependency Injection with Kodein](http://www.baeldung.com/kotlin-kodein-dependency-injection)
- [Regular Expressions in Kotlin](http://www.baeldung.com/kotlin-regular-expressions)
- [Objects in Kotlin](http://www.baeldung.com/kotlin-objects)
- [Reading from a File in Kotlin](http://www.baeldung.com/kotlin-read-file)
@@ -28,13 +25,15 @@
- [Filtering Kotlin Collections](http://www.baeldung.com/kotlin-filter-collection)
- [Writing to a File in Kotlin](http://www.baeldung.com/kotlin-write-file)
- [Lambda Expressions in Kotlin](http://www.baeldung.com/kotlin-lambda-expressions)
-- [Writing Specifications with Kotlin and Spek](http://www.baeldung.com/kotlin-spek)
-- [Processing JSON with Kotlin and Klaxson](http://www.baeldung.com/kotlin-json-klaxson)
- [Kotlin String Templates](http://www.baeldung.com/kotlin-string-template)
-- [Java EE 8 Security API](http://www.baeldung.com/java-ee-8-security)
-- [Kotlin with Ktor](http://www.baeldung.com/kotlin-ktor)
- [Working with Enums in Kotlin](http://www.baeldung.com/kotlin-enum)
- [Create a Java and Kotlin Project with Maven](http://www.baeldung.com/kotlin-maven-java-project)
- [Reflection with Kotlin](http://www.baeldung.com/kotlin-reflection)
- [Get a Random Number in Kotlin](http://www.baeldung.com/kotlin-random-number)
- [Idiomatic Logging in Kotlin](http://www.baeldung.com/kotlin-logging)
+- [Kotlin Constructors](https://www.baeldung.com/kotlin-constructors)
+- [Creational Design Patterns in Kotlin: Builder](https://www.baeldung.com/kotlin-builder-pattern)
+- [Kotlin Nested and Inner Classes](https://www.baeldung.com/kotlin-inner-classes)
+- [Kotlin with Ktor](https://www.baeldung.com/kotlin-ktor)
+- [Fuel HTTP Library with Kotlin](https://www.baeldung.com/kotlin-fuel)
+- [Introduction to Kovenant Library for Kotlin](https://www.baeldung.com/kotlin-kovenant)
diff --git a/core-kotlin/build.gradle b/core-kotlin/build.gradle
index 6c1e06aa25..2b6527fca7 100755
--- a/core-kotlin/build.gradle
+++ b/core-kotlin/build.gradle
@@ -6,7 +6,6 @@ version '1.0-SNAPSHOT'
buildscript {
ext.kotlin_version = '1.2.41'
- ext.ktor_version = '0.9.2'
repositories {
mavenCentral()
@@ -44,14 +43,6 @@ sourceSets {
}
dependencies {
- compile "io.ktor:ktor-server-netty:$ktor_version"
compile "ch.qos.logback:logback-classic:1.2.1"
- compile "io.ktor:ktor-gson:$ktor_version"
testCompile group: 'junit', name: 'junit', version: '4.12'
- implementation 'com.beust:klaxon:3.0.1'
-
-}
-task runServer(type: JavaExec) {
- main = 'APIServer'
- classpath = sourceSets.main.runtimeClasspath
}
\ No newline at end of file
diff --git a/core-kotlin/kotlin-ktor/webapp/WEB-INF/web.xml b/core-kotlin/kotlin-ktor/webapp/WEB-INF/web.xml
deleted file mode 100755
index 513a80cb27..0000000000
--- a/core-kotlin/kotlin-ktor/webapp/WEB-INF/web.xml
+++ /dev/null
@@ -1,35 +0,0 @@
-
-
-
-
-
-
- io.ktor.ktor.config
- application.conf
-
-
-
- KtorServlet
- KtorServlet
- io.ktor.server.servlet.ServletApplicationEngine
-
-
- true
-
-
-
- 304857600
- 304857600
- 0
-
-
-
-
- KtorServlet
- /
-
-
-
\ No newline at end of file
diff --git a/core-kotlin/pom.xml b/core-kotlin/pom.xml
index 6fdc7c7c1a..0894a57320 100644
--- a/core-kotlin/pom.xml
+++ b/core-kotlin/pom.xml
@@ -12,33 +12,7 @@
../parent-kotlin