Update to Java 11 APIs

CHANGELOG.md

@@ -8,7 +8,12 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ## 2.0.0
 ### Backward incompatible changes
 #### Common
-- Flow API is now used from `java.util.concurrent.Flow`, Helidon specific `Flow` class is now removed
+- Removed `io.helidon.reactive.Flow`, please use `java.util.concurrent.Flow`
+- Removed `io.helidon.common.CollectionsHelper`, please use factory methods of `Set`, `Map` and `List`
+- Removed `io.helidon.common.OptionalHelper`, please use methods of `java.util.Optional`
+- Removed `io.helidon.common.StackWalker`, please use `java.lang.StackWalker`
+- Removed `io.helidon.common.InputStreamHelper`, please use `java.io.InputStream` methods
+
 #### Tracing
 - We have upgraded to OpenTracing version 0.33.0 that is not backward compatible, the following breaking changes exist
     (these are OpenTracing changes, not Helidon changes):

archetypes/mp/src/main/resources/archetype-resources/src/main/java/__applicationName__.java.vm

@@ -6,8 +6,6 @@ import javax.enterprise.context.ApplicationScoped;
 import javax.ws.rs.ApplicationPath;
 import javax.ws.rs.core.Application;
 
-import io.helidon.common.CollectionsHelper;
-
 /**
  * Simple JAXRS Application that registers one resource class.
  */
@@ -17,6 +15,6 @@ public class ${applicationName} extends Application {
 
     @Override
     public Set<Class<?>> getClasses() {
-        return CollectionsHelper.setOf(${restResourceName}.class);
+        return Set.of(${restResourceName}.class);
     }
 }

common/common/src/main/java/io/helidon/common/Errors.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2018 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2019 Oracle and/or its affiliates. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -56,7 +56,7 @@
 @SuppressWarnings("WeakerAccess")
 public final class Errors extends LinkedList<Errors.ErrorMessage> {
     private static final Set<StackWalker.Option> WALKER_OPTIONS =
-            CollectionsHelper.setOf(StackWalker.Option.RETAIN_CLASS_REFERENCE);
+            Set.of(StackWalker.Option.RETAIN_CLASS_REFERENCE);
 
     private final boolean hasFatal;
     private final boolean hasWarning;