Add Java 16 test class ...

README.md

@@ -27,5 +27,6 @@ This project includes unit tests for key functionalities introduced in each Java
 - [Java 13](src/test/java/pl/mperor/lab/java/Java13.java)
 - [Java 14](src/test/java/pl/mperor/lab/java/Java14.java)
 - [Java 15](src/test/java/pl/mperor/lab/java/Java15.java)
+- [Java 16](src/test/java/pl/mperor/lab/java/Java16.java)
 
 For detailed examples and tests of each feature, please refer to the individual source files linked above.

src/test/java/pl/mperor/lab/java/Java16.java

@@ -0,0 +1,107 @@
+package pl.mperor.lab.java;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.DisabledIf;
+import org.junit.jupiter.api.condition.EnabledIfSystemProperty;
+import pl.mperor.lab.TestUtils;
+
+import java.io.IOException;
+import java.time.LocalTime;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+import java.util.Locale;
+import java.util.stream.Collectors;
+
+/**
+ * Java 16 (March 2021)
+ */
+public class Java16 {
+
+    @Test
+    public void testPeriodSupport() {
+        LocalTime date = LocalTime.parse("16:00:00");
+        // symbol "B" alternative to the am/pm format
+        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("h B", Locale.US);
+        Assertions.assertEquals("4 in the afternoon", date.format(formatter));
+    }
+
+    @Test
+    public void testStreamToList() {
+        var source = List.of(1, 2, 3);
+        var toList = source.stream().toList();
+        var collectToList = source.stream().collect(Collectors.toList());
+        Assertions.assertEquals(toList, collectToList);
+    }
+
+    @Test
+    public void testLocalElements() {
+        var out = TestUtils.setTempSystemOut();
+
+        interface LocalInterface {
+            default void call() {
+                System.out.println("Local interface work!");
+            }
+        }
+
+        record LocalRecord() implements LocalInterface {
+            @Override
+            public void call() {
+                System.out.println("Local records work!");
+            }
+        }
+
+        enum LocalEnum implements LocalInterface {
+            SINGLE;
+
+            @Override
+            public void call() {
+                System.out.println("Local enums work!");
+            }
+        }
+
+        new LocalRecord().call();
+        LocalEnum.SINGLE.call();
+        new LocalInterface() {}.call();
+
+        var lines = out.lines();
+        Assertions.assertEquals("Local records work!", lines.getFirst());
+        Assertions.assertEquals("Local enums work!", lines.getSecond());
+        Assertions.assertEquals("Local interface work!", lines.getThird());
+        TestUtils.resetSystemOut();
+    }
+
+    @SuppressWarnings({"removal", "synchronization"})
+    @Test
+    public void testValueBasedClasses() {
+        // warning: new Long(...) has been deprecated and marked for removal
+        Long longByConstructor = new Long(13);
+
+        // warning: attempt to synchronize on an instance of a value-based class
+        synchronized (longByConstructor) {
+            System.out.println("From the synchronized block!");
+        }
+
+        Long longByFactoryMethod = Long.valueOf(13L);
+        Assertions.assertFalse(longByConstructor == longByFactoryMethod);
+        Assertions.assertTrue(longByConstructor.equals(longByFactoryMethod));
+        Assertions.assertTrue(Long.valueOf(13L) == longByFactoryMethod);
+    }
+
+    @Disabled("Dependent on the OS and additional libraries, besides having a long execution time.")
+    @Test
+    public void testJPackage() throws IOException, InterruptedException {
+        Process process = new ProcessBuilder(
+                "jpackage",
+                "--name", "j16pack",
+                "--input", "./build/libs",
+                "--main-jar", "JavaLab-1.0-SNAPSHOT.jar",
+                "--main-class", "pl.mperor.lab.java.Main"
+        ).start();
+
+        Assertions.assertEquals(0, process.waitFor());
+        process.destroy();
+    }
+
+}