Bael 7050 Java 21 New Features (#15870)

* BAEL-7050 Java 21 New Features

* BAEL-7050 Formatted the pom.xml file

* BAEL-7050 Moved the codebase to existing core-java-21 project

* Removed the old pom.xml reference

* Removed the old core-java-21-new-features project

* BAEL-7050 PR Review Changes

* BAEL-7050 Using JUnit5 in test cases

* BAEL-7050 Using JUnit5 in test cases

* BAEL-7050 Removed the public modifier from JUnit class and methods

core-java-modules/core-java-21/src/main/java/com/baeldung/java21/PatternCaseLabels.java

@@ -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;
+    }
+}

core-java-modules/core-java-21/src/main/java/com/baeldung/java21/RecordPattern.java

@@ -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;
+    }
+}

core-java-modules/core-java-21/src/main/java/com/baeldung/java21/StringTemplates.java

@@ -0,0 +1,9 @@
+package com.baeldung.java21;
+
+public class StringTemplates {
+
+    public String getStringTemplate() {
+        String name = "Baeldung"; 
+        return STR."Welcome to \{name}"; 
+    }
+}

core-java-modules/core-java-21/src/main/java/com/baeldung/java21/SwitchPattern.java

@@ -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;
+    }
+}

core-java-modules/core-java-21/src/test/java/com/baeldung/java21/PatternCaseLabelsUnitTest.java

@@ -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"));
+    }
+   
+}

core-java-modules/core-java-21/src/test/java/com/baeldung/java21/RecordPatternUnitTest.java

@@ -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));
+    }
+}

core-java-modules/core-java-21/src/test/java/com/baeldung/java21/StringTemplateUnitTest.java

@@ -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());
+    }
+}

core-java-modules/core-java-21/src/test/java/com/baeldung/java21/SwitchPatternUnitTest.java

@@ -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);
+    }
+}