Add test class for Java 11 ...

README.md

@@ -22,5 +22,6 @@ This project includes unit tests for key functionalities introduced in each Java
 - [Java 1.8 (Java 8)](src/test/java/pl/mperor/lab/java/Java8.java)
 - [Java 9](src/test/java/pl/mperor/lab/java/Java9.java)
 - [Java 10](src/test/java/pl/mperor/lab/java/Java10.java)
+- [Java 11](src/test/java/pl/mperor/lab/java/Java11.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/Java11.java

@@ -0,0 +1,80 @@
+package pl.mperor.lab.java;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.AbstractMap.SimpleEntry;
+import java.util.List;
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+/**
+ * Java 11 (September 2018)
+ */
+public class Java11 {
+
+    @Test
+    public void testStringAPIEnhancements() {
+        Assertions.assertTrue("  ".isBlank());
+        Assertions.assertFalse("Java 11".isBlank());
+
+        Assertions.assertEquals("***", "  ***  ".strip());
+        Assertions.assertEquals("***  ", "  ***  ".stripLeading());
+        Assertions.assertEquals("  ***", "  ***  ".stripTrailing());
+
+        String multiline = """
+                First
+                Second
+                Third""";
+        Assertions.assertEquals(3, multiline.lines().count());
+
+        Assertions.assertEquals("DDD", "D".repeat(3));
+    }
+
+    @Test
+    public void testPredicateNot() {
+        String nonBlankJoined = Stream.of("a", "", "b", "   ", "c")
+                .filter(Predicate.not(String::isBlank))
+                .collect(Collectors.joining());
+
+        Assertions.assertEquals("abc", nonBlankJoined);
+    }
+
+    @Test
+    public void testTransferTo() throws Exception {
+        String data = "Java 11 InputStream transferTo method";
+
+        try (ByteArrayInputStream input = new ByteArrayInputStream(data.getBytes(StandardCharsets.UTF_8));
+             ByteArrayOutputStream output = new ByteArrayOutputStream()) {
+
+            input.transferTo(output);
+
+            String result = output.toString(StandardCharsets.UTF_8);
+            Assertions.assertEquals(data, result);
+        }
+    }
+
+    @Test
+    public void testTeeingCollector() {
+        List<String> words = List.of("one", "two", "three");
+
+        SimpleEntry<Integer, Long> pair = words.stream().collect(Collectors.teeing(
+                Collectors.summingInt(String::length),
+                Collectors.counting(),
+                SimpleEntry::new)
+        );
+
+        Assertions.assertEquals(11, pair.getKey());
+        Assertions.assertEquals(3, pair.getValue());
+    }
+
+    @Test
+    public void testCollectionToArray() {
+        Assertions.assertArrayEquals(new String[]{"x", "y", "z"}, List.of("x", "y", "z").toArray(String[]::new));
+    }
+
+}