From 2986930aa26959a651e97bb9d86aa325e44b5b43 Mon Sep 17 00:00:00 2001
From: Dai MIKURUBE <dmikurube@acm.org>
Date: Wed, 11 Sep 2024 16:49:49 +0900
Subject: [PATCH] Fix LoadedClassFinder

---
 .../junit5/engine/EmbulkPluginTestEngine.java |  5 ++-
 .../junit5/engine/LoadedClassFinder.java      | 37 +++++++++++++++----
 2 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/embulk-junit5-engine/src/main/java/org/embulk/junit5/engine/EmbulkPluginTestEngine.java b/embulk-junit5-engine/src/main/java/org/embulk/junit5/engine/EmbulkPluginTestEngine.java
index eba4e2c..e914e36 100644
--- a/embulk-junit5-engine/src/main/java/org/embulk/junit5/engine/EmbulkPluginTestEngine.java
+++ b/embulk-junit5-engine/src/main/java/org/embulk/junit5/engine/EmbulkPluginTestEngine.java
@@ -138,10 +138,11 @@ public final Optional<String> getArtifactId() {
     private static Class<?> findOrLoadClassFrom(final ClassLoader klassLoader, final String name) {
         final Class<?> foundClass = LoadedClassFinder.findFrom(klassLoader, name);
         if (foundClass != null) {
-            logger.info(() -> "\"" + name + "\" has been already loaded: " + foundClass.toString());
+            logger.info(() -> "<" + name + "> has been already loaded in [" + klassLoader + "]: " + foundClass.toString());
+            return foundClass;
         }
 
-        logger.info(() -> "\"" + name + "\" has not been loaded.");
+        logger.info(() -> "<" + name + "> has not been loaded in [" + klassLoader + "].");
         try {
             return Class.forName(name);  // <= TODO: Load it under PluginClassLoader !
         } catch (final ClassNotFoundException ex) {
diff --git a/embulk-junit5-engine/src/main/java/org/embulk/junit5/engine/LoadedClassFinder.java b/embulk-junit5-engine/src/main/java/org/embulk/junit5/engine/LoadedClassFinder.java
index e14f7de..b01506f 100644
--- a/embulk-junit5-engine/src/main/java/org/embulk/junit5/engine/LoadedClassFinder.java
+++ b/embulk-junit5-engine/src/main/java/org/embulk/junit5/engine/LoadedClassFinder.java
@@ -16,14 +16,37 @@
 
 package org.embulk.junit5.engine;
 
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
 class LoadedClassFinder extends ClassLoader {
-    private LoadedClassFinder(final ClassLoader inner) {
-        this.inner = inner;
-    }
+    static synchronized Class<?> findFrom(final ClassLoader classLoader, final String name) {
+        final Method findLoadedClass;
+        try {
+            findLoadedClass = ClassLoader.class.getDeclaredMethod("findLoadedClass", String.class);
+        } catch (final NoSuchMethodException ex) {
+            throw new RuntimeException(ex);
+        }
 
-    static Class<?> findFrom(final ClassLoader classLoader, final String name) {
-        return (new LoadedClassFinder(classLoader)).findLoadedClass(name);
-    }
+        findLoadedClass.setAccessible(true);
+        try {
+            final Object classObject;
+            try {
+                classObject = findLoadedClass.invoke(classLoader, name);
+            } catch (final IllegalAccessException | InvocationTargetException ex) {
+                throw new RuntimeException(ex);
+            }
 
-    private final ClassLoader inner;
+            if (classObject == null) {
+                return null;
+            }
+            if (classObject instanceof Class) {
+                return (Class<?>) classObject;
+            } else {
+                throw new RuntimeException();
+            }
+        } finally {
+            findLoadedClass.setAccessible(false);
+        }
+    }
 }