Updates to ReflectionUtils Implementation (Azure#26268)

Updates to ReflectionUtils implementation

Author: alzimmermsft

sdk/core/azure-core/src/main/java9/com/azure/core/implementation/ReflectionUtils.java

@@ -34,30 +34,29 @@ final class ReflectionUtils implements ReflectionUtilsApi {
     public MethodHandles.Lookup getLookupToUse(Class<?> targetClass) throws Throwable {
         Module responseModule = targetClass.getModule();
 
-        /*
-         * First check if the response class's module is exported to all unnamed modules. If it is we will use
-         * MethodHandles.publicLookup() which is meant for creating MethodHandle instances for publicly accessible
-         * classes.
-         */
-        if (responseModule.isExported("")) {
-            return MethodHandles.publicLookup();
+        // The unnamed module is opened unconditionally, have Core read it and use a private proxy lookup to enable all
+        // lookup scenarios.
+        if (!responseModule.isNamed()) {
+            CORE_MODULE.addReads(responseModule);
+            return MethodHandles.privateLookupIn(targetClass, LOOKUP);
+        }
+
+
+        // If the response module is the Core module return the Core private lookup.
+        if (responseModule == CORE_MODULE) {
+            return LOOKUP;
         }
 
-        /*
-         * Otherwise, we use the MethodHandles.Lookup which is associated to this (com.azure.core) module, and more
-         * specifically, is tied to this class (ReflectionUtils). But, in order to use this lookup we need to ensure
-         * that the com.azure.core module reads the response class's module as the lookup won't have permissions
-         * necessary to create the MethodHandle instance without it.
-         *
-         * This logic is safe due to the fact that any SDK module calling into this code path will already need to open
-         * to com.azure.core as it needs to perform other reflective operations on classes in the module. Adding the
-         * com.azure.core reads is handling specifically required by MethodHandle.
-         */
-        if (!CORE_MODULE.canRead(responseModule)) {
+        // Next check if the target class module is opened either unconditionally or to Core's module. If so, also use
+        // a private proxy lookup to enable all lookup scenarios.
+        if (responseModule.isOpen(targetClass.getPackageName())
+            || responseModule.isOpen(targetClass.getPackageName(), CORE_MODULE)) {
             CORE_MODULE.addReads(responseModule);
+            return MethodHandles.privateLookupIn(targetClass, LOOKUP);
         }
 
-        return LOOKUP;
+        // Otherwise, return the public lookup as there are no specialty ways to access the other module.
+        return MethodHandles.publicLookup();
     }
 
     public int getJavaImplementationMajorVersion() {
@@ -66,4 +65,4 @@ public int getJavaImplementationMajorVersion() {
 
     ReflectionUtils() {
     }
-}
+}

sdk/mixedreality/azure-mixedreality-authentication/src/main/java/module-info.java

@@ -10,7 +10,5 @@
     exports com.azure.mixedreality.authentication;
 
     opens com.azure.mixedreality.authentication.implementation.models
-        to com.fasterxml.jackson.databind;
-    exports com.azure.mixedreality.authentication.implementation.models
         to com.fasterxml.jackson.databind, com.azure.core;
 }

sdk/template/azure-sdk-template/src/main/java/com/azure/sdk/template/implementation/Hidden.java

@@ -0,0 +1,18 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.azure.sdk.template.implementation;
+
+/**
+ * This is an implementation sample class for template app.
+ */
+public class Hidden {
+    /**
+     * Implementation sample method.
+     *
+     * @return implementation message
+     */
+    public String getImplementationMessage() {
+        return "hidden";
+    }
+}

sdk/template/azure-sdk-template/src/main/java/com/azure/sdk/template/implementation/package-info.java

@@ -0,0 +1,7 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+/**
+ * This package contains implementation classes for the template project.
+ */
+package com.azure.sdk.template.implementation;

sdk/template/azure-sdk-template/src/main/java/module-info.java

@@ -2,5 +2,10 @@
 // Licensed under the MIT License.
 
 module com.azure.sdk.template {
+    // All public packages should be exported unconditionally so that all consumers may access their public APIs.
     exports com.azure.sdk.template;
+
+    // Implementation packages that contain service request or response models need to be opened to azure-core
+    // and Jackson Databind to allow their reflective operations to perform correctly.
+    opens com.azure.sdk.template.implementation to com.azure.core, com.fasterxml.jackson.databind;
 }