Improving Loom examples

README.md

@@ -14,7 +14,7 @@ A repository to review the main concepts about Functional Programming with Java.
 sdk env install
 ./mvnw clean test -DexcludedGroups=performance,endtoend
 ./mvnw clean test -DexcludedGroups=performance,endtoend -pl training
-./mvnw clean test -DexcludedGroups=performance,endtoend -Dtest=FunctionalInterfacesExamplesTest -pl training
+./mvnw clean test -DexcludedGroups=performance,endtoend -Dtest=LoomExamplesTest -pl training
 ./mvnw clean test -Dgroups=performance
 ./mvnw clean test -Dgroups=endtoend
 
@@ -27,7 +27,7 @@ sdk env install
 ## Functional programming features in Java
 
 - [x] Lambda Expressions (Functional interfaces, Functions, Supplier, Consumer & Predicates)
-- [x] Optionals 
+- [x] Optional 
 - [x] Stream API 
 - [x] CompletableFuture & Structural Concurrency
 - [ ] Immutable Lists
@@ -39,9 +39,9 @@ sdk env install
 
 | Java Version | Feature                                                                             | Date      | Release notes                                                          |
 |--------------|-------------------------------------------------------------------------------------|-----------|------------------------------------------------------------------------|
-| Java 8       | - Lambda Expressions - Optionals - Stream API - CompletableFuture                   | 18/3/2014 | https://www.oracle.com/java/technologies/javase/8-whats-new.html       |
+| Java 8       | - Lambda Expressions - Optional - Stream API - CompletableFuture                   | 18/3/2014 | https://www.oracle.com/java/technologies/javase/8-whats-new.html       |
 | Java 9       | - CompletableFuture updates                                                         | 21/9/2017 | https://www.oracle.com/java/technologies/javase/9-all-relnotes.html    |
-| Java 10      | - Optionals updates - Immutable Lists                                               | 20/3/2018 | https://www.oracle.com/java/technologies/javase/10-relnote-issues.html |
+| Java 10      | - Optional updates - Immutable Lists                                               | 20/3/2018 | https://www.oracle.com/java/technologies/javase/10-relnote-issues.html |
 | Java 11      | - Not Predicate operator - Local-Variable Syntax for Lambda                         | 25/9/2018 | https://www.oracle.com/java/technologies/javase/11all-relnotes.html    |
 | Java 12      | - Teeing Collector - Pattern Matching                                               | 19/3/2019 | https://www.oracle.com/java/technologies/javase/12-relnote-issues.html |
 | Java 13      | - Switch Expressions enhancements                                                   | 17/9/2019 | https://www.oracle.com/java/technologies/javase/13-relnote-issues.html |

training/src/main/java/info/jab/fp/async/LoomExamples.java

@@ -0,0 +1,80 @@
+package info.jab.fp.async;
+
+import java.util.concurrent.StructuredTaskScope;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class LoomExamples {
+
+    private static final Logger logger = LoggerFactory.getLogger(LoomExamples.class);
+
+    public void usingVThread1() {
+        try {
+            // virtual thread
+            var vthread = Thread.ofVirtual()
+                .name("virtual-", 0)
+                .start(() -> {
+                    logger.info("virtual " + Thread.currentThread());
+                });
+
+            vthread.join();
+        } catch (InterruptedException e) {
+
+        }
+    }
+
+    private static final ThreadLocal<String> USER = new ThreadLocal<>();
+
+    public String usingVThread2() {
+        USER.set("White");
+        try {
+            var vthread = Thread.ofVirtual().start(() -> {
+                USER.set("Black");
+                logger.info("Hello " + USER.get());
+                USER.remove();
+                logger.info("Hello " + USER.get());
+            });
+            vthread.join();
+        } catch (InterruptedException e) { }
+        return USER.get();
+    }
+
+    //TODO Review ScopedValue in detail
+    private static final ScopedValue<String> USER2 = ScopedValue.newInstance();
+
+    public String usingVThread3() {
+
+        ScopedValue.runWhere(USER2, "Black", () -> {});
+        try {
+            var vthread = Thread.ofVirtual()
+            .start(() -> {
+              ScopedValue.runWhere(USER2, "White", () -> {
+                logger.info("Hello " + USER2.get());
+              });
+            });
+            vthread.join();
+        } catch (InterruptedException e) { }
+        return USER2.get();
+    }
+
+    public Integer usingVThread4() {
+        try (var scope = new StructuredTaskScope<Integer>()) {
+            var task1 = scope.fork(() -> {
+                Thread.sleep(1_000);
+                return 1;
+            });
+            var task2 = scope.fork(() -> {
+                Thread.sleep(1_000);
+                return 2;
+            });
+
+            try {
+                scope.join();
+            } catch (InterruptedException e) { }
+
+            var result = task1.get() + task2.get();
+            return result;
+        }
+    }
+}