From a6015eff7d22a7bcad3740ef779bb4142a54faf8 Mon Sep 17 00:00:00 2001
From: Lukas Jungmann <lukas.jungmann@oracle.com>
Date: Sat, 29 Apr 2023 17:16:46 +0200
Subject: [PATCH]  #635: The hk2 service loader is not used everywhere (where
 necessary)

Signed-off-by: Lukas Jungmann <lukas.jungmann@oracle.com>
---
 api/src/main/java/jakarta/mail/Session.java   | 55 ++++++++++++++++++-
 .../java/jakarta/mail/util/FactoryFinder.java |  8 ++-
 doc/release/CHANGES.txt                       |  1 +
 3 files changed, 60 insertions(+), 4 deletions(-)

diff --git a/api/src/main/java/jakarta/mail/Session.java b/api/src/main/java/jakarta/mail/Session.java
index bf23b5d3..78596e89 100644
--- a/api/src/main/java/jakarta/mail/Session.java
+++ b/api/src/main/java/jakarta/mail/Session.java
@@ -25,6 +25,7 @@
 import java.io.PrintStream;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
 import java.net.InetAddress;
 import java.net.URL;
 import java.security.AccessController;
@@ -35,6 +36,7 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Hashtable;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
@@ -986,7 +988,17 @@ public void load(InputStream is) throws IOException {
 		    if (!containsDefaultProvider(p))
 		    	addProvider(p);
 		}
-	
+
+		// + handle Glassfish/OSGi (platform specific default)
+		if (isHk2Available()) {
+			Iterator<Provider> iter = lookupUsingHk2ServiceLoader(Provider.class.getName());
+			while (iter.hasNext()) {
+				Provider p = iter.next();
+				if (!containsDefaultProvider(p))
+					addProvider(p);
+			}
+		}
+
 		// load the META-INF/javamail.providers file supplied by an application
 		loadAllResources("META-INF/javamail.providers", cl, loader);
 	
@@ -999,7 +1011,18 @@ public void load(InputStream is) throws IOException {
 		    if (containsDefaultProvider(p))
 		    	addProvider(p);
 		}
-	
+
+		// + handle Glassfish/OSGi (platform specific default)
+		if (isHk2Available()) {
+			Iterator<Provider> iter = lookupUsingHk2ServiceLoader(Provider.class.getName());
+			while (iter.hasNext()) {
+				Provider p = iter.next();
+				if (containsDefaultProvider(p)) {
+					addProvider(p);
+				}
+			}
+		}
+
 		/*
 		 * If we haven't loaded any providers, fake it.
 		 */
@@ -1366,6 +1389,34 @@ public InputStream run() throws IOException {
     EventQueue getEventQueue() {
     	return q;
     }
+
+    private static final String OSGI_SERVICE_LOADER_CLASS_NAME = "org.glassfish.hk2.osgiresourcelocator.ServiceLoader";
+
+    private static boolean isHk2Available() {
+        try {
+            Class.forName(OSGI_SERVICE_LOADER_CLASS_NAME);
+            return true;
+        } catch (ClassNotFoundException ignored) {
+        }
+        return false;
+    }
+
+    @SuppressWarnings({"unchecked"})
+    private <T> Iterator<T> lookupUsingHk2ServiceLoader(String factoryId) {
+        try {
+            // Use reflection to avoid having any dependency on HK2 ServiceLoader class
+            Class<?> serviceClass = Class.forName(factoryId);
+            Class<?>[] args = new Class<?>[]{serviceClass};
+            Class<?> target = Class.forName(OSGI_SERVICE_LOADER_CLASS_NAME);
+            Method m = target.getMethod("lookupProviderInstances", Class.class);
+            Iterable<T> result = ((Iterable<T>) m.invoke(null, (Object[]) args));
+            return result != null ? result.iterator() : Collections.emptyIterator();
+        } catch (Exception ignored) {
+            // log and continue
+            return Collections.emptyIterator();
+        }
+    }
+
 }
 
 /**
diff --git a/api/src/main/java/jakarta/mail/util/FactoryFinder.java b/api/src/main/java/jakarta/mail/util/FactoryFinder.java
index 59a3d175..da06c1c6 100644
--- a/api/src/main/java/jakarta/mail/util/FactoryFinder.java
+++ b/api/src/main/java/jakarta/mail/util/FactoryFinder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2022 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2023 Oracle and/or its affiliates. All rights reserved.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0, which is available at
@@ -105,7 +105,11 @@ private static <T> T lookupUsingHk2ServiceLoader(String factoryId) {
             Class<?>[] args = new Class<?>[]{serviceClass};
             Class<?> target = Class.forName(OSGI_SERVICE_LOADER_CLASS_NAME);
             Method m = target.getMethod("lookupProviderInstances", Class.class);
-            Iterator<?> iter = ((Iterable<?>) m.invoke(null, (Object[]) args)).iterator();
+            Iterable<?> iterable = ((Iterable<?>) m.invoke(null, (Object[]) args));
+            if (iterable == null) {
+                return null;
+            }
+            Iterator<?> iter = iterable.iterator();
             return iter.hasNext() ? (T) iter.next() : null;
         } catch (Exception ignored) {
             // log and continue
diff --git a/doc/release/CHANGES.txt b/doc/release/CHANGES.txt
index fda437c2..961ddbd2 100644
--- a/doc/release/CHANGES.txt
+++ b/doc/release/CHANGES.txt
@@ -22,6 +22,7 @@ longer available.
 		  CHANGES IN THE 2.1.2 RELEASE
           ----------------------------
 E  629  jakarta.mail-api-2.1.0.jar does not work in OSGi environment (hk2servicelocator)
+E  635  The hk2 service loader is not used everywhere (where necessary)
 E  660  jakarta.mail-api is not a Multi Release JAR
 E  664  Typo in Session.setDebug Javadoc