Merge branch 'master' into BAEL-6421-PrintWriter-write-vs-print

2024-04-07 13:51:18 +03:00
parent e4aa7a1206 5e58a1a0b7
commit 6a04c9921c
394 changed files with 5446 additions and 1812 deletions
@@ -0,0 +1,44 @@
+package com.baeldung.inetspi;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.Arrays;
+import java.util.stream.Stream;
+
+import com.baeldung.inetspi.providers.CustomAddressResolverImpl;
+
+public class InetAddressSPI {
+    public String usingGetByName(String host) throws UnknownHostException {
+        InetAddress inetAddress =  InetAddress.getByName(host);
+        return inetAddress.getHostAddress();
+    }
+
+    public String[] usingGetAllByName(String host) throws UnknownHostException {
+        InetAddress[] inetAddresses =  InetAddress.getAllByName(host);
+        return Arrays.stream(inetAddresses).map(InetAddress::getHostAddress).toArray(String[]::new);
+    }
+
+    public String usingGetByIp(byte[] ip) throws UnknownHostException {
+        InetAddress inetAddress =  InetAddress.getByAddress(ip);
+
+        return inetAddress.getHostName();
+    }
+
+    public String usingGetByIpAndReturnsCannonName(byte[] ip) throws UnknownHostException {
+        InetAddress inetAddress =  InetAddress.getByAddress(ip);
+
+        return inetAddress.getCanonicalHostName();
+    }
+
+    public String getHostUsingCustomImpl(byte[] ip) throws UnknownHostException {
+
+        CustomAddressResolverImpl imp = new CustomAddressResolverImpl();
+        return imp.get(null).lookupByAddress(ip);
+    }
+
+    public Stream<InetAddress> getIpUsingCustomImpl(String host) throws UnknownHostException {
+
+        CustomAddressResolverImpl imp = new CustomAddressResolverImpl();
+        return imp.get(null).lookupByName(host, null);
+    }
+}
@@ -0,0 +1,56 @@
+package com.baeldung.inetspi;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.logging.Logger;
+import java.util.stream.Stream;
+
+public class Registry {
+    private final Map<String, List<byte[]>> registry;
+
+    private static final Logger LOGGER = Logger.getLogger(Registry.class.getName());
+
+    public Registry() {
+        registry = loadMapWithData();
+    }
+
+    public Stream<InetAddress> getAddressesfromHost(String host) throws UnknownHostException {
+        LOGGER.info("Performing Forward Lookup for HOST : " + host);
+        if (!registry.containsKey(host)) {
+            throw new UnknownHostException("Missing Host information in Resolver");
+        }
+        return registry.get(host)
+          .stream()
+          .map(add -> constructInetAddress(host, add))
+          .filter(Objects::nonNull);
+    }
+
+    public String getHostFromAddress(byte[] arr) throws UnknownHostException {
+        LOGGER.info("Performing Reverse Lookup for Address : " + Arrays.toString(arr));
+        for (Map.Entry<String, List<byte[]>> entry : registry.entrySet()) {
+            if (entry.getValue()
+              .stream()
+              .anyMatch(ba -> Arrays.equals(ba, arr))) {
+                return entry.getKey();
+            }
+        }
+        throw new UnknownHostException("Address Not Found");
+    }
+
+    private Map<String, List<byte[]>> loadMapWithData() {
+        return Map.of("baeldung-local.org", List.of(new byte[] { 1, 2, 3, 4 }));
+    }
+
+    private static InetAddress constructInetAddress(String host, byte[] address) {
+        try {
+            return InetAddress.getByAddress(host, address);
+        } catch (UnknownHostException unknownHostException) {
+            return null;
+        }
+    }
+
+}
@@ -0,0 +1,42 @@
+package com.baeldung.inetspi.providers;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.net.spi.InetAddressResolver;
+import java.net.spi.InetAddressResolverProvider;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.logging.Logger;
+import java.util.stream.Stream;
+
+import com.baeldung.inetspi.Registry;
+
+public class CustomAddressResolverImpl extends InetAddressResolverProvider {
+
+    private static Logger LOGGER = Logger.getLogger(CustomAddressResolverImpl.class.getName());
+
+    private static Registry registry = new Registry();
+
+    @Override
+    public InetAddressResolver get(Configuration configuration) {
+        LOGGER.info("Using Custom Address Resolver :: " + this.name());
+        LOGGER.info("Registry initialised");
+        return new InetAddressResolver() {
+            @Override
+            public Stream<InetAddress> lookupByName(String host, LookupPolicy lookupPolicy) throws UnknownHostException {
+                return registry.getAddressesfromHost(host);
+            }
+
+            @Override
+            public String lookupByAddress(byte[] addr) throws UnknownHostException {
+                return registry.getHostFromAddress(addr);
+            }
+        };
+    }
+
+    @Override
+    public String name() {
+        return "CustomInternetAddressResolverImpl";
+    }
+}
@@ -0,0 +1,31 @@
+package com.baeldung.inetspi;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.stream.Stream;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class InetAddressSPIUnitTest {
+    @Test
+    public void givenInetAddress_whenUsingInetAddress_thenPerformResolution() throws UnknownHostException {
+        InetAddressSPI spi = new InetAddressSPI();
+        Assert.assertNotNull(spi.usingGetByName("www.google.com"));
+        Assert.assertTrue(spi.usingGetAllByName("www.google.com").length > 1);
+        Assert.assertNotNull(spi.usingGetByIp(InetAddress.getByName("www.google.com")
+          .getAddress()));
+        Assert.assertNotNull(spi.usingGetByIpAndReturnsCannonName(InetAddress.getByName("www.google.com")
+          .getAddress()));
+    }
+
+    @Test
+    public void givenCustomInetAddressImplementation_whenUsingInetAddress_thenPerformResolution() throws UnknownHostException {
+        InetAddressSPI spi = new InetAddressSPI();
+        Assert.assertEquals("baeldung-local.org", spi.getHostUsingCustomImpl(new byte[] { 1, 2, 3, 4 }));
+        Stream<InetAddress> response = spi.getIpUsingCustomImpl("baeldung-local.org");
+        Assert.assertArrayEquals(new byte[] { 1, 2, 3, 4 }, response.findFirst()
+          .get()
+          .getAddress());
+    }
+}
@@ -0,0 +1,32 @@
+package com.baeldung.java21;
+
+public class PatternCaseLabels {
+
+    static String processInputOld(String input) {
+        String output;
+        switch (input) {
+        case null -> output = "Oops, null";
+        case String s -> {
+            if ("Yes".equalsIgnoreCase(s)) {
+                output = "It's Yes";
+            } else if ("No".equalsIgnoreCase(s)) {
+                output = "It's No";
+            } else {
+                output = "Try Again";
+            }
+        }
+        }
+        return output;
+    }
+
+    static String processInputNew(String input) {
+        String output;
+        switch (input) {
+        case null -> output = "Oops, null";
+        case String s when "Yes".equalsIgnoreCase(s) -> output = "It's Yes";
+        case String s when "No".equalsIgnoreCase(s) -> output = "It's No";
+        case String s -> output = "Try Again";
+        }
+        return output;
+    }
+}
@@ -0,0 +1,36 @@
+package com.baeldung.java21;
+
+public class RecordPattern {
+
+    record Point(int x, int y) {}
+    
+    public static int beforeRecordPattern(Object obj) {
+        int sum = 0;
+        if(obj instanceof Point p) {
+            int x = p.x();
+            int y = p.y();
+            sum = x+y;
+        }
+        return sum;
+    }
+    
+    public static int afterRecordPattern(Object obj) {
+        if(obj instanceof Point(int x, int y)) {
+           return x+y;
+        }
+        return 0;
+    }
+    
+    enum Color {RED, GREEN, BLUE}
+    
+    record ColoredPoint(Point point, Color color) {}
+    
+    record RandomPoint(ColoredPoint cp) {}
+    
+    public static Color getRamdomPointColor(RandomPoint r) {
+        if(r instanceof RandomPoint(ColoredPoint cp)) {
+            return cp.color();
+        }
+        return null;
+    }
+}
@@ -0,0 +1,9 @@
+package com.baeldung.java21;
+
+public class StringTemplates {
+
+    public String getStringTemplate() {
+        String name = "Baeldung"; 
+        return STR."Welcome to \{name}"; 
+    }
+}
@@ -0,0 +1,56 @@
+package com.baeldung.java21;
+
+public class SwitchPattern {
+    
+    static class Account{
+        double getBalance() {
+            return 0;
+        }
+    }
+    
+    static class SavingsAccount extends Account {
+        @Override
+        double getBalance() {
+            return 100;
+        } 
+    }
+    
+    static class TermAccount extends Account {
+        @Override
+        double getBalance() {
+            return 1000;
+        } 
+    }
+    static class CurrentAccount extends Account {
+        @Override
+        double getBalance() {
+            return 10000;
+        } 
+    }
+    
+    static double getBalanceWithOutSwitchPattern(Account account) {
+        double balance = 0;
+        if(account instanceof SavingsAccount sa) {
+            balance = sa.getBalance();
+        }
+        else if(account instanceof TermAccount ta) {
+            balance = ta.getBalance();
+        }
+        else if(account instanceof CurrentAccount ca) {
+            balance = ca.getBalance();
+        }
+        return balance;
+    }
+    
+    static double getBalanceWithSwitchPattern(Account account) {
+        double result;
+        switch (account) {
+            case null -> throw new IllegalArgumentException("Oops, account is null");
+            case SavingsAccount sa -> result = sa.getBalance();
+            case TermAccount ta -> result = ta.getBalance();
+            case CurrentAccount ca -> result = ca.getBalance();
+            default -> result = account.getBalance();
+        }
+        return result;
+    }
+}
@@ -0,0 +1,48 @@
+package com.baeldung.java21;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+
+class PatternCaseLabelsUnitTest {
+
+    @Test
+    void whenProcessInputOldWayWithYes_thenReturnOutput() {
+        assertEquals("It's Yes", PatternCaseLabels.processInputOld("Yes"));
+    }
+    
+    @Test
+    void whenProcessInputOldWayWithNo_thenReturnOutput() {
+        assertEquals("It's No", PatternCaseLabels.processInputOld("No"));
+    }
+    
+    @Test
+    void whenProcessInputOldWayWithNull_thenReturnOutput() {
+        assertEquals("Oops, null", PatternCaseLabels.processInputOld(null));
+    }
+    
+    @Test
+    void whenProcessInputOldWayWithInvalidOption_thenReturnOutput() {
+        assertEquals("Try Again", PatternCaseLabels.processInputOld("Invalid Option"));
+    }
+    
+    @Test
+    void whenProcessInputNewWayWithYes_thenReturnOutput() {
+        assertEquals("It's Yes", PatternCaseLabels.processInputNew("Yes"));
+    }
+    
+    @Test
+    void whenProcessInputNewWayWithNo_thenReturnOutput() {
+        assertEquals("It's No", PatternCaseLabels.processInputNew("No"));
+    }
+    
+    @Test
+    void whenProcessInputNewWayWithNull_thenReturnOutput() {
+        assertEquals("Oops, null", PatternCaseLabels.processInputNew(null));
+    }
+    
+    @Test
+    void whenProcessInputNewWayWithInvalidOption_thenReturnOutput() {
+        assertEquals("Try Again", PatternCaseLabels.processInputNew("Invalid Option"));
+    }
+   
+}
@@ -0,0 +1,29 @@
+package com.baeldung.java21;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.java21.RecordPattern.Color;
+import com.baeldung.java21.RecordPattern.ColoredPoint;
+import com.baeldung.java21.RecordPattern.Point;
+import com.baeldung.java21.RecordPattern.RandomPoint;
+
+class RecordPatternUnitTest {
+
+    @Test
+    void whenNoRecordPattern_thenReturnOutput() {
+        assertEquals(5, RecordPattern.beforeRecordPattern(new Point(2, 3)));
+    }
+    
+    @Test
+    void whenRecordPattern_thenReturnOutput() {
+        assertEquals(5, RecordPattern.afterRecordPattern(new Point(2, 3)));
+    }
+    
+    @Test
+    void whenRecordPattern_thenReturnColorOutput() {
+        ColoredPoint coloredPoint = new ColoredPoint(new Point(2, 3), Color.GREEN);
+        RandomPoint randomPoint = new RandomPoint(coloredPoint);
+        assertEquals(Color.GREEN, RecordPattern.getRamdomPointColor(randomPoint));
+    }
+}
@@ -0,0 +1,13 @@
+package com.baeldung.java21;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+
+class StringTemplateUnitTest {
+
+    @Test
+    void whenNoSwitchPattern_thenReturnSavingsAccountBalance() {
+        StringTemplates stringTemplates = new StringTemplates();
+        assertEquals("Welcome to Baeldung", stringTemplates.getStringTemplate());
+    }
+}
@@ -0,0 +1,19 @@
+package com.baeldung.java21;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+
+class SwitchPatternUnitTest {
+
+    @Test
+    void whenNoSwitchPattern_thenReturnSavingsAccountBalance() {
+        SwitchPattern.SavingsAccount savingsAccount = new SwitchPattern.SavingsAccount();
+        assertEquals(100, SwitchPattern.getBalanceWithOutSwitchPattern(savingsAccount), 0);
+    }
+    
+    @Test
+    void whenSwitchPattern_thenReturnSavingsAccountBalance() {
+        SwitchPattern.SavingsAccount savingsAccount = new SwitchPattern.SavingsAccount();
+        assertEquals(100, SwitchPattern.getBalanceWithSwitchPattern(savingsAccount), 0);
+    }
+}
@@ -0,0 +1,2 @@
+### Relevant Articles:
+- [Find Map Keys with Duplicate Values in Java](https://www.baeldung.com/java-map-find-keys-repeated-values)
@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-collections-maps-8</artifactId>
+    <name>core-java-collections-maps-8</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <artifactId>core-java-modules</artifactId>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <configuration>
+                    <argLine>
+                        --add-opens java.base/java.util=ALL-UNNAMED
+                    </argLine>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>
@@ -0,0 +1,127 @@
+package com.baeldung.map.valuetokeyset;
+
+import static java.util.stream.Collectors.collectingAndThen;
+import static java.util.stream.Collectors.groupingBy;
+import static java.util.stream.Collectors.mapping;
+import static java.util.stream.Collectors.toSet;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.junit.jupiter.api.Test;
+
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.Multimaps;
+import com.google.common.collect.SetMultimap;
+
+public class ConvertMapKeyValueToMapValueKeySetUnitTest {
+
+    private static final Map<String, String> INPUT_MAP = Map.of(
+        // @formatter:off
+        "Kai", "Linux",
+        "Eric", "MacOS",
+        "Kevin", "Windows",
+        "Liam", "MacOS",
+        "David", "Linux",
+        "Saajan", "Windows",
+        "Loredana", "MacOS"
+        // @formatter:on
+    );
+
+    private static final Map<String, Set<String>> EXPECTED = Map.of(
+        // @formatter:off
+        "Linux", Set.of("Kai", "David"),
+        "Windows", Set.of("Saajan", "Kevin"),
+        "MacOS", Set.of("Eric", "Liam", "Loredana")
+        // @formatter:on
+    );
+
+    private static final Map<String, String> INPUT_MAP_WITH_NULLS = new HashMap<String, String>(INPUT_MAP) {{
+        put("Tom", null);
+        put("Jerry", null);
+        put(null, null);
+    }};
+
+    private static final Map<String, Set<String>> EXPECTED_WITH_NULLS = new HashMap<String, Set<String>>(EXPECTED) {{
+        put(null, new HashSet<String>() {{
+            add("Tom");
+            add("Jerry");
+            add(null);
+        }});
+    }};
+
+    public static <K, V> Map<V, Set<K>> transformMap(Map<K, V> input) {
+        Map<V, Set<K>> resultMap = new HashMap<>();
+        for (Map.Entry<K, V> entry : input.entrySet()) {
+            if (!resultMap.containsKey(entry.getValue())) {
+                resultMap.put(entry.getValue(), new HashSet<>());
+            }
+            resultMap.get(entry.getValue())
+                .add(entry.getKey());
+        }
+        return resultMap;
+    }
+
+    @Test
+    void whenUsingClassicLoopBasedSolution_thenGetExpectedResult() {
+        Map<String, Set<String>> result = transformMap(INPUT_MAP);
+        assertEquals(EXPECTED, result);
+
+        Map<String, Set<String>> result2 = transformMap(INPUT_MAP_WITH_NULLS);
+        assertEquals(EXPECTED_WITH_NULLS, result2);
+    }
+
+    @Test
+    void whenUsingJava8StreamGroupingBy_thenGetExpectedResult() {
+        Map<String, Set<String>> result = INPUT_MAP.entrySet()
+            .stream()
+            .collect(groupingBy(Map.Entry::getValue, mapping(Map.Entry::getKey, toSet())));
+        assertEquals(EXPECTED, result);
+
+        assertThrows(NullPointerException.class, () -> INPUT_MAP_WITH_NULLS.entrySet()
+            .stream()
+            .collect(groupingBy(Map.Entry::getValue, mapping(Map.Entry::getKey, toSet()))));
+    }
+
+    @Test
+    void whenUsingJava8ForEach_thenGetExpectedResult() {
+        Map<String, Set<String>> result = new HashMap<>();
+        INPUT_MAP.forEach((key, value) -> result.computeIfAbsent(value, k -> new HashSet<>())
+            .add(key));
+        assertEquals(EXPECTED, result);
+
+        Map<String, Set<String>> result2 = new HashMap<>();
+        INPUT_MAP_WITH_NULLS.forEach((key, value) -> result2.computeIfAbsent(value, k -> new HashSet<>())
+            .add(key));
+        assertEquals(EXPECTED_WITH_NULLS, result2);
+    }
+
+    @Test
+    void whenUsingGuavaMultiMapCollector_thenGetExpectedResult() {
+        Map<String, Set<String>> result = INPUT_MAP.entrySet()
+            .stream()
+            .collect(collectingAndThen(Multimaps.toMultimap(Map.Entry::getValue, Map.Entry::getKey, HashMultimap::create), Multimaps::asMap));
+        assertEquals(EXPECTED, result);
+
+        Map<String, Set<String>> result2 = INPUT_MAP_WITH_NULLS.entrySet()
+            .stream()
+            .collect(collectingAndThen(Multimaps.toMultimap(Map.Entry::getValue, Map.Entry::getKey, HashMultimap::create), Multimaps::asMap));
+        assertEquals(EXPECTED_WITH_NULLS, result2);
+    }
+
+    @Test
+    void whenUsingGuavaInvertFromAndForMap_thenGetExpectedResult() {
+        SetMultimap<String, String> multiMap = Multimaps.invertFrom(Multimaps.forMap(INPUT_MAP), HashMultimap.create());
+        Map<String, Set<String>> result = Multimaps.asMap(multiMap);
+        assertEquals(EXPECTED, result);
+
+        SetMultimap<String, String> multiMapWithNulls = Multimaps.invertFrom(Multimaps.forMap(INPUT_MAP_WITH_NULLS), HashMultimap.create());
+        Map<String, Set<String>> result2 = Multimaps.asMap(multiMapWithNulls);
+        assertEquals(EXPECTED_WITH_NULLS, result2);
+    }
+
+}
@@ -6,4 +6,5 @@
 - [How to Get First Item From a Java Set](https://www.baeldung.com/first-item-set)
 - [Cartesian Product of Any Number of Sets in Java](https://www.baeldung.com/java-cartesian-product-sets)
 - [How to Get Index of an Item in Java Set](https://www.baeldung.com/java-set-element-find-index)
+- [Check if an Element Is Present in a Set in Java](https://www.baeldung.com/java-set-membership)
 - More articles: [[<-- prev]](/core-java-modules/core-java-collections-set)
@@ -0,0 +1,71 @@
+package com.baeldung.checkifpresentinset;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.apache.commons.collections4.CollectionUtils;
+import org.apache.commons.collections4.SetUtils;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+class CheckIfPresentInSetUnitTest {
+
+    private static final Set<String> CITIES = new HashSet<>();
+
+    @BeforeAll
+    static void setup() {
+        CITIES.add("Paris");
+        CITIES.add("London");
+        CITIES.add("Tokyo");
+        CITIES.add("Tamassint");
+        CITIES.add("New york");
+    }
+
+    @Test
+    void givenASet_whenUsingStreamAnyMatchMethod_thenCheck() {
+        boolean isPresent = CITIES.stream()
+            .anyMatch(city -> city.equals("London"));
+
+        assertThat(isPresent).isTrue();
+    }
+
+    @Test
+    void givenASet_whenUsingStreamFilterMethod_thenCheck() {
+        long resultCount = CITIES.stream()
+            .filter(city -> city.equals("Tamassint"))
+            .count();
+
+        assertThat(resultCount).isPositive();
+    }
+
+    @Test
+    void givenASet_whenUsingContainsMethod_thenCheck() {
+        assertThat(CITIES.contains("London")).isTrue();
+        assertThat(CITIES.contains("Madrid")).isFalse();
+    }
+
+    @Test
+    void givenASet_whenUsingCollectionsDisjointMethod_thenCheck() {
+        boolean isPresent = !Collections.disjoint(CITIES, Collections.singleton("Paris"));
+
+        assertThat(isPresent).isTrue();
+    }
+
+    @Test
+    void givenASet_whenUsingCollectionUtilsContainsAnyMethod_thenCheck() {
+        boolean isPresent = CollectionUtils.containsAny(CITIES, Collections.singleton("Paris"));
+
+        assertThat(isPresent).isTrue();
+    }
+
+    @Test
+    void givenASet_whenUsingSetUtilsIntersectionMethod_thenCheck() {
+        Set<String> result = SetUtils.intersection(CITIES, Collections.singleton("Tamassint"));
+
+        assertThat(result).isNotEmpty();
+    }
+
+}
@@ -86,7 +86,7 @@
        <maven.compiler.target>1.8</maven.compiler.target>
        <jcabi-aspects.version>0.22.6</jcabi-aspects.version>
        <aspectjrt.version>1.9.20.1</aspectjrt.version>
-        <cactoos.version>0.43</cactoos.version>
+        <cactoos.version>0.55.0</cactoos.version>
        <ea-async.version>1.2.3</ea-async.version>
        <jcabi-maven-plugin.version>0.14.1</jcabi-maven-plugin.version>
        <aspectjtools.version>1.9.20.1</aspectjtools.version>
@@ -5,3 +5,4 @@ This module contains articles about converting between Java date and time object
 ### Relevant Articles: 
 - [Convert Gregorian to Hijri Date in Java](https://www.baeldung.com/java-date-gregorian-hijri-conversion)
 - [Convert String Date to XMLGregorianCalendar in Java](https://www.baeldung.com/java-string-date-xmlgregoriancalendar-conversion)
+- [Convert TemporalAccessor to LocalDate](https://www.baeldung.com/java-temporalaccessor-localdate-conversion)
@@ -0,0 +1,31 @@
+package com.baeldung.TemporalAccessorToLocalDate;
+
+import org.junit.Test;
+
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.time.temporal.TemporalAccessor;
+import java.time.temporal.TemporalQueries;
+
+import static org.junit.Assert.assertEquals;
+
+public class TemporalAccessorToLocalDateUnitTest {
+    String dateString = "2022-03-28";
+    TemporalAccessor temporalAccessor = DateTimeFormatter.ISO_LOCAL_DATE.parse(dateString);
+
+    @Test
+    public void givenTemporalAccessor_whenUsingLocalDateFrom_thenConvertToLocalDate() {
+        LocalDate convertedDate = LocalDate.from(temporalAccessor);
+        assertEquals(LocalDate.of(2022, 3, 28), convertedDate);
+    }
+
+    @Test
+    public void givenTemporalAccessor_whenUsingTemporalQueries_thenConvertToLocalDate() {
+        int year = temporalAccessor.query(TemporalQueries.localDate()).getYear();
+        int month = temporalAccessor.query(TemporalQueries.localDate()).getMonthValue();
+        int day = temporalAccessor.query(TemporalQueries.localDate()).getDayOfMonth();
+
+        LocalDate convertedDate = LocalDate.of(year, month, day);
+        assertEquals(LocalDate.of(2022, 3, 28), convertedDate);
+    }
+}
@@ -0,0 +1,45 @@
+package com.baeldung.openhtmlfiles;
+
+import org.junit.Test;
+
+import java.awt.*;
+import java.io.File;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.net.URL;
+
+import static org.junit.Assert.*;
+
+public class OpenHtmlFilesUnitTest {
+    public URL url;
+    public String absolutePath;
+
+    public OpenHtmlFilesUnitTest() throws URISyntaxException {
+        url = getClass().getResource("/test.html");
+        assert url != null;
+        File file = new File(url.toURI());
+        if (!file.exists()) {
+            fail();
+        }
+        absolutePath = file.getAbsolutePath();
+    }
+    /*
+    @Test
+    public void givenHtmlFile_whenUsingDesktopClass_thenOpenFileInDefaultBrowser() throws IOException {
+        File htmlFile = new File(absolutePath);
+        Desktop.getDesktop().browse(htmlFile.toURI());
+        assertTrue(true);
+    }
+    */
+    @Test
+    public void givenHtmlFile_whenUsingProcessBuilder_thenOpenFileInDefaultBrowser() throws IOException {
+        ProcessBuilder pb;
+        if (System.getProperty("os.name").toLowerCase().contains("win")) {
+            pb = new ProcessBuilder("cmd.exe", "/c", "start", absolutePath);
+        } else {
+            pb = new ProcessBuilder("xdg-open", absolutePath);
+        }
+        pb.start();
+        assertTrue(true);
+    }
+}
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html>
+<head>
+	<meta charset="utf-8">
+	<meta name="viewport" content="width=device-width, initial-scale=1">
+	<title>
+		
+
+	</title>
+</head>
+<body>
+
+	<h1>Hello dear friend</h1>
+</body>
+</html>
@@ -11,3 +11,4 @@ This module contains articles about core Java input/output(IO) APIs.
 - [PrintWriter vs. FileWriter in Java](https://www.baeldung.com/java-printwriter-filewriter-difference)
 - [Read Input Character-by-Character in Java](https://www.baeldung.com/java-read-input-character)
 - [Difference Between flush() and close() in Java FileWriter](https://www.baeldung.com/java-filewriter-flush-vs-close)
+- [Get a Path to a Resource in a Java JAR File](https://www.baeldung.com/java-get-path-resource-jar)
@@ -0,0 +1,32 @@
+package com.baeldung.getpathtoresource;
+
+import org.junit.Test;
+
+import java.net.URL;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Objects;
+
+import static org.junit.Assert.assertNotNull;
+
+public class GetPathToResourceUnitTest {
+
+    @Test
+    public void givenFile_whenClassUsed_thenGetResourcePath() {
+        URL resourceUrl = GetPathToResourceUnitTest.class.getResource("/sampleText1.txt");
+        assertNotNull(resourceUrl);
+    }
+
+    @Test
+    public void givenFile_whenClassLoaderUsed_thenGetResourcePath() {
+        URL resourceUrl = GetPathToResourceUnitTest.class.getClassLoader().getResource("sampleText1.txt");
+        assertNotNull(resourceUrl);
+    }
+
+    @Test
+    public void givenFile_whenPathUsed_thenGetResourcePath() throws Exception {
+        Path resourcePath = Paths.get(Objects.requireNonNull(GetPathToResourceUnitTest.class.getResource("/sampleText1.txt")).toURI());
+        assertNotNull(resourcePath);
+    }
+
+}
@@ -13,3 +13,4 @@ This module contains articles about core Java input/output(IO) APIs.
 - [Difference Between FileReader and BufferedReader in Java](https://www.baeldung.com/java-filereader-vs-bufferedreader)
 - [Read Multiple Inputs on the Same Line in Java](https://www.baeldung.com/java-read-multiple-inputs-same-line)
 - [Write Console Output to Text File in Java](https://www.baeldung.com/java-write-console-output-file)
+- [Java InputStream vs. InputStreamReader](https://www.baeldung.com/java-inputstream-vs-inputstreamreader)
@@ -11,28 +11,28 @@ public class UrlCheckerIntegrationTest {
    @Test
    public void givenValidUrl_WhenUsingHEAD_ThenReturn200() throws IOException {
        UrlChecker tester = new UrlChecker();
-        int responseCode = tester.getResponseCodeForURLUsingHead("http://www.example.com");
+        int responseCode = tester.getResponseCodeForURLUsingHead("https://httpbin.org/status/200");
        assertEquals(200, responseCode);
    }
    
    @Test
    public void givenInvalidIUrl_WhenUsingHEAD_ThenReturn404() throws IOException {
        UrlChecker tester = new UrlChecker();
-        int responseCode = tester.getResponseCodeForURLUsingHead("http://www.example.com/xyz");
+        int responseCode = tester.getResponseCodeForURLUsingHead("https://httpbin.org/status/404");
        assertEquals(404, responseCode);
    }
    
    @Test
    public void givenValidUrl_WhenUsingGET_ThenReturn200() throws IOException {
        UrlChecker tester = new UrlChecker();
-        int responseCode = tester.getResponseCodeForURL("http://www.example.com");
+        int responseCode = tester.getResponseCodeForURL("https://httpbin.org/status/200");
        assertEquals(200, responseCode);
    }
    
    @Test
    public void givenInvalidIUrl_WhenUsingGET_ThenReturn404() throws IOException {
        UrlChecker tester = new UrlChecker();
-        int responseCode = tester.getResponseCodeForURL("http://www.example.com/xyz");
+        int responseCode = tester.getResponseCodeForURL("https://httpbin.org/status/404");
        assertEquals(404, responseCode);
    }
    
@@ -0,0 +1,43 @@
+import java.util.Map;
+
+public class UseHashMapToConvertPhoneNumberInWordsToNumber {
+    private static Map<String, Integer> multipliers = Map.of("double",2,
+            "triple", 3,
+            "quadruple", 4);
+    private static Map<String, String> digits = Map.of("zero","1",
+            "one", "1",
+            "two", "2",
+            "three", "3",
+            "four", "4",
+            "five", "5",
+            "six", "6",
+            "seven", "7",
+            "eight", "8",
+            "nine", "9");
+
+
+    public static String convertPhoneNumberInWordsToNumber(String phoneNumberInWord) {
+
+        StringBuilder output = new StringBuilder();
+        Integer currentMultiplier = null;
+        String[] words = phoneNumberInWord.split(" ");
+
+        for (String word : words) {
+            Integer multiplier = multipliers.get(word);
+            if (multiplier != null) {
+                if (currentMultiplier != null) {
+                    throw new IllegalArgumentException("Cannot have consecutive multipliers, at: " + word);
+                }
+                currentMultiplier = multiplier;
+            } else {
+                String digit = digits.get(word);
+                if (digit == null) {
+                    throw new IllegalArgumentException("Invalid word: " + word);
+                }
+                output.append(digit.repeat(currentMultiplier != null ? currentMultiplier : 1));
+                currentMultiplier = null;
+            }
+        }
+        return output.toString();
+    }
+}
@@ -0,0 +1,64 @@
+public class UseSwitchToConvertPhoneNumberInWordsToNumber {
+
+    public static String convertPhoneNumberInWordsToNumber(String phoneNumberInWord) {
+
+        StringBuilder output = new StringBuilder();
+        Integer currentMultiplier = null;
+        String[] words = phoneNumberInWord.split(" ");
+
+        for (String word : words) {
+            Integer multiplier = getWordAsMultiplier(word);
+            if (multiplier != null) {
+                if (currentMultiplier != null) {
+                    throw new IllegalArgumentException("Cannot have consecutive multipliers, at: " + word);
+                }
+                currentMultiplier = multiplier;
+            } else {
+                output.append(getWordAsDigit(word).repeat(currentMultiplier != null ? currentMultiplier : 1));
+                currentMultiplier = null;
+            }
+        }
+        return output.toString();
+    }
+
+    public static Integer getWordAsMultiplier(String word) {
+        switch (word) {
+            case "double":
+                return 2;
+            case "triple":
+                return 3;
+            case "quadruple":
+                return 4;
+            default:
+                return null;
+        }
+    }
+
+    public static String getWordAsDigit(String word) {
+        switch (word) {
+            case "zero":
+                return "0";
+            case "one":
+                return "1";
+            case "two":
+                return "2";
+            case "three":
+                return "3";
+            case "four":
+                return "4";
+            case "five":
+                return "5";
+            case "six":
+                return "6";
+            case "seven":
+                return "7";
+            case "eight":
+                return "8";
+            case "nine":
+                return "9";
+            default:
+                throw new IllegalArgumentException("Invalid word: " + word);
+        }
+    }
+
+}
@@ -0,0 +1,31 @@
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+
+class UseHashMapToConvertPhoneNumberInWordsToNumberUnitTest {
+
+    @Test
+    void givenStringWithWhiteSpaces_WhenConvertPhoneNumberInWordsToNumber_ThenEquivalentNumber() {
+
+        assertEquals("5248888",
+                UseHashMapToConvertPhoneNumberInWordsToNumber
+                        .convertPhoneNumberInWordsToNumber("five two four quadruple eight"));
+    }
+
+    @Test
+    void givenStringEndingWithConseutiveMultipliers_WhenConvertPhoneNumberInWordsToNumber_ThenThrowException() {
+
+        assertThrows(IllegalArgumentException.class, () -> {
+            UseHashMapToConvertPhoneNumberInWordsToNumber
+                    .convertPhoneNumberInWordsToNumber("five eight three double triple");
+        });
+    }
+
+    @Test
+    void givenStringWithInvalidWords_WhenConvertPhoneNumberInWordsToNumber_ThenThrowException() {
+
+        assertThrows(IllegalArgumentException.class, () -> {
+            UseHashMapToConvertPhoneNumberInWordsToNumber
+                    .convertPhoneNumberInWordsToNumber("five eight three two four penta null eight");
+        });
+    }
+}
@@ -0,0 +1,62 @@
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class UseSwitchToConvertPhoneNumberInWordsToNumberUnitTest {
+
+    @Test
+    void givenStringWithWhiteSpaces_WhenConvertPhoneNumberInWordsToNumber_ThenEquivalentNumber() {
+
+        assertEquals("5248888",
+                UseSwitchToConvertPhoneNumberInWordsToNumber
+                        .convertPhoneNumberInWordsToNumber("five two four quadruple eight"));
+
+    }
+
+    @Test
+    void givenStringEndingWithConseutiveMultipliers_WhenConvertPhoneNumberInWordsToNumber_ThenThrowException() {
+
+        assertThrows(IllegalArgumentException.class, () -> {
+            UseSwitchToConvertPhoneNumberInWordsToNumber
+                    .convertPhoneNumberInWordsToNumber("five eight three double triple");
+        });
+    }
+
+    @Test
+    void givenStringWithInvalidWords_WhenConvertPhoneNumberInWordsToNumber_ThenThrowException() {
+
+        assertThrows(IllegalArgumentException.class, () -> {
+            UseSwitchToConvertPhoneNumberInWordsToNumber
+                    .convertPhoneNumberInWordsToNumber("five eight three two four penta null eight");
+        });
+    }
+
+
+    @Test
+    void givenString_WhenGetWordAsMultiplier_ThenEquivalentNumber() {
+        assertEquals(2, UseSwitchToConvertPhoneNumberInWordsToNumber
+                .getWordAsMultiplier("double"));
+    }
+
+    @Test
+    void givenInvalidString_WhenGetWordAsMultiplier_ThenReturnNull() {
+        assertEquals(null, UseSwitchToConvertPhoneNumberInWordsToNumber
+                .getWordAsMultiplier("hexa"));
+
+    }
+
+    @Test
+    void givenString_WhenMapIndividualDigits_ThenEquivalentNumber() {
+        assertEquals("5",
+                UseSwitchToConvertPhoneNumberInWordsToNumber
+                        .getWordAsDigit("five"));
+    }
+
+    @Test
+    void givenInvalidString_WhenMapIndividualDigits_ThenThrowException() {
+        assertThrows(IllegalArgumentException.class, () -> {
+            UseSwitchToConvertPhoneNumberInWordsToNumber
+                    .convertPhoneNumberInWordsToNumber("penta");
+        });
+    }
+}
@@ -8,3 +8,4 @@
 - [Get the Initials of a Name in Java](https://www.baeldung.com/java-shorten-name-initials)
 - [Normalizing the EOL Character in Java](https://www.baeldung.com/java-normalize-end-of-line-character)
 - [Converting UTF-8 to ISO-8859-1 in Java](https://www.baeldung.com/java-utf-8-iso-8859-1-conversion)
+- [Get Last n Characters From a String](https://www.baeldung.com/java-string-get-last-n-characters)
@@ -0,0 +1,64 @@
+package com.baeldung.lastncharacters;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.Arrays;
+import java.util.stream.Collectors;
+
+import org.apache.commons.lang3.ArrayUtils;
+import org.apache.commons.lang3.StringUtils;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class LastNCharactersUnitTest {
+
+    private String s;
+    private int n;
+
+    @BeforeEach
+    void init() {
+        s = "10-03-2024";
+        n = 4;
+    }
+
+    @Test
+    void givenString_whenUsingIntStreamAsStreamSource_thenObtainLastNCharacters() {
+        String result = s.chars()
+            .mapToObj(c -> (char) c)
+            .skip(s.length() - n)
+            .map(String::valueOf)
+            .collect(Collectors.joining());
+
+        assertThat(result).isEqualTo("2024");
+    }
+
+    @Test
+    void givenString_whenUsingOneArgSubstringMethod_thenObtainLastNCharacters() {
+        int beginIndex = s.length() - n;
+
+        assertThat(s.substring(beginIndex)).isEqualTo("2024");
+    }
+
+    @Test
+    void givenString_whenUsingStreamOfCharactersAsSource_thenObtainLastNCharacters() {
+        String result = Arrays.stream(ArrayUtils.toObject(s.toCharArray()))
+            .skip(s.length() - n)
+            .map(String::valueOf)
+            .collect(Collectors.joining());
+
+        assertThat(result).isEqualTo("2024");
+    }
+
+    @Test
+    void givenString_whenUsingStringUtilsRight_thenObtainLastNCharacters() {
+        assertThat(StringUtils.right(s, n)).isEqualTo("2024");
+    }
+
+    @Test
+    void givenString_whenUsingTwoArgSubstringMethod_thenObtainLastNCharacters() {
+        int beginIndex = s.length() - n;
+        String result = s.substring(beginIndex, s.length());
+
+        assertThat(result).isEqualTo("2024");
+    }
+}
@@ -99,6 +99,7 @@
        <module>core-java-collections-maps-2</module>
        <module>core-java-collections-maps-3</module>
        <module>core-java-collections-maps-7</module>
+        <module>core-java-collections-maps-8</module>
        <module>core-java-compiler</module>
        <module>core-java-concurrency-2</module>
        <module>core-java-concurrency-advanced</module>