Merge pull request #29 from trishagee/java21

Java 21

java-samples/src/main/java/com/jetbrains/code/jdk/preview/PatternMatchingForSwitch.java → java-samples/src/main/java/com/jetbrains/code/jdk21/PatternMatchingForSwitch.java

@@ -1,35 +1,39 @@
-package com.jetbrains.code.jdk.preview;
+package com.jetbrains.code.jdk21;
 
 import java.util.List;
 
 /**
  * <ul>
  *     <li>#PreviewFeature First Preview #JDK17</li>
+ *     <li>#StandardFeature #JDK21</li>
  * </ul>
+ * See: <a href="https://openjdk.org/jeps/441">JEP 441</a>
  */
 @SuppressWarnings("unused")
 public class PatternMatchingForSwitch {
-    static String exampleJEP406OriginalCode(Object o) {
+    // Prior to Java 21
+    static String exampleJEP411OriginalCode(Object obj) {
         String formatted = "unknown";
-        if (o instanceof Integer i) {
+        if (obj instanceof Integer i) {
             formatted = String.format("int %d", i);
-        } else if (o instanceof Long l) {
+        } else if (obj instanceof Long l) {
             formatted = String.format("long %d", l);
-        } else if (o instanceof Double d) {
+        } else if (obj instanceof Double d) {
             formatted = String.format("double %f", d);
-        } else if (o instanceof String s) {
+        } else if (obj instanceof String s) {
             formatted = String.format("String %s", s);
         }
         return formatted;
     }
 
-    static String exampleJEP406PatternMatchingForSwitch(Object o) {
-        return switch (o) {
+    // As of Java 21
+    static String formatterPatternSwitch(Object obj) {
+        return switch (obj) {
             case Integer i -> String.format("int %d", i);
             case Long l -> String.format("long %d", l);
             case Double d -> String.format("double %f", d);
             case String s -> String.format("String %s", s);
-            default -> o.toString();
+            default -> obj.toString();
         };
     }
 
@@ -65,4 +69,20 @@ static void testFooBar(String s) {
             default -> System.out.println("Ok");
         }
     }
+
+    // As of Java 21
+    static void testStringNew(String response) {
+        switch (response) {
+            case null -> {}
+            case "y", "Y" -> System.out.println("You got it");
+            case "n", "N" -> System.out.println("Shame");
+            case String s
+                    when s.equalsIgnoreCase("YES") -> System.out.println("You got it");
+            case String s
+                    when s.equalsIgnoreCase("NO") -> System.out.println("Shame");
+            case String s -> {
+                System.out.println("Sorry?");
+            }
+        }
+    }
 }

java-samples/src/main/java/com/jetbrains/code/jdk21/Point.java

@@ -0,0 +1,4 @@
+package com.jetbrains.code.jdk21;
+
+record Point(int x, int y) {
+}

java-samples/src/main/java/com/jetbrains/code/jdk21/RecordPatterns.java

@@ -0,0 +1,28 @@
+package com.jetbrains.code.jdk21;
+
+/**
+ * <ul>
+ *     <li>#StandardFeature #JDK21</li>
+ * </ul>
+ * See: <a href="https://openjdk.org/jeps/440">JEP 440</a>
+ */
+public class RecordPatterns {
+
+    // Not sure why, but the inspection doesn't seem to trigger for this code
+    static int sum(Object obj) {
+        if (obj instanceof Point p) {
+            int x = p.x();
+            int y = p.y();
+            return (x + y);
+        }
+        return 0;
+    }
+
+    static int sumUpdated(Object obj) {
+        if (obj instanceof Point(int x, int y)) {
+            return (x+y);
+        }
+        return 0;
+    }
+}
+

java-samples/src/main/java/com/jetbrains/code/jdk21/StringTemplate.java

@@ -0,0 +1,9 @@
+package com.jetbrains.code.jdk21;
+
+@SuppressWarnings("unused")
+public class StringTemplate {
+    private void templateCanBeUsed() {
+        String name = "Bob";
+        String greeting = "Hello, " + name + ". You are " + 29 + " years old.";
+    }
+}

java-samples/src/test/com/jetbrains/code/jdk21/RecordPatternsTest.java

@@ -0,0 +1,28 @@
+package com.jetbrains.code.jdk21;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+class RecordPatternsTest {
+    @Test
+    @DisplayName("Should sum point values")
+    void shouldSum() {
+        // when
+        int sum = RecordPatterns.sum(new Point(1, 2));
+
+        // then
+        Assertions.assertEquals(3, sum);
+    }
+
+    @Test
+    @DisplayName("Should sum points with JDK21")
+    void shouldSumPointsWithJdk21() {
+        // when
+        int sum = RecordPatterns.sumUpdated(new Point(1, 2));
+
+        // then
+        Assertions.assertEquals(3, sum);
+    }
+
+}