Java 21 Scoped Value

Author: lokeshgupta1981

src/main/java/com/howtodoinjava/newFeatures/java21/ScopedValueTest.java

@@ -0,0 +1,103 @@
+import java.util.concurrent.StructuredTaskScope;
+
+public class ScopedValueTest {
+
+  //public static ThreadLocal<String> CONTEXT = ThreadLocal.withInitial(() -> null);
+  //public static InheritableThreadLocal<String> CONTEXT = new InheritableThreadLocal();
+
+  private static final ScopedValue<String> CONTEXT = ScopedValue.newInstance();
+
+
+
+  public static void main(String[] args) {
+
+
+
+    /*ScopedValue.runWhere(CONTEXT, "TestValue", () -> {
+
+      doSomething();
+
+      try (var scope = new StructuredTaskScope<String>()) {
+
+        scope.fork(() -> insideChildThread());
+
+        try{
+          scope.join();
+        } catch (InterruptedException ex) {
+          //...
+        }
+        
+      }
+    });*/
+
+
+    ScopedValueTest instance = new ScopedValueTest();
+
+    ScopedValue.runWhere(CONTEXT, "Test Value", () -> {
+
+      System.out.println("In parent thread start the scoped value is: " + CONTEXT.get());
+      instance.doSomething();
+      System.out.println("In parent thread end the scoped value is: " + CONTEXT.get());
+    });
+
+    System.out.println("Outside bounded scope isBound() is: " + CONTEXT.isBound()); 
+    System.out.println("Outside bounded scope the scoped value is: " + CONTEXT.orElse(null));
+  
+
+  
+
+
+
+
+
+
+
+
+
+
+
+    /*Thread parentThread = new Thread(() -> {
+
+      CONTEXT.set("TestValue");
+      insideParentThread_1();
+
+      Thread childThread = new Thread(() -> {
+          insideChildThread();
+      });
+
+      childThread.start();
+      insideParentThread_2();
+    });
+
+    parentThread.start();*/
+  }
+
+  public void doSomething() {
+    System.out.println("In doSomething() and parent scope: " + CONTEXT.get());
+    ScopedValue.runWhere(CONTEXT, "Changed Value", () -> {
+      System.out.println("In doSomething() and child scope: " + CONTEXT.get());
+      doSomethingAgain();
+    });
+  }
+
+  public void doSomethingAgain() {
+    System.out.println("In doSomethingAgain() and child scope: " + CONTEXT.get());
+  }
+
+  /*static void doSomething() {
+      System.out.println("Scoped Value in doSomething(): " + CONTEXT.get());
+  }
+
+  static void insideParentThread_1() {
+      System.out.println("ThreadLocal Value in insideParentThread_1(): " + CONTEXT.get());
+  }
+
+  static void insideParentThread_2() {
+      System.out.println("ThreadLocal Value in insideParentThread_2(): " + CONTEXT.get());
+  }
+
+  static String insideChildThread() {
+      System.out.println("Scoped Value in insideChildThread(): " + CONTEXT.get());
+      return CONTEXT.get();
+  }*/
+}