8375350: Remove usage of AppContext from javax.imageio implementation

Reviewed-by: kizune, dnguyen

Author: prrace

src/java.desktop/share/classes/javax/imageio/ImageIO.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -47,7 +47,6 @@
 import javax.imageio.spi.ServiceRegistry;
 import javax.imageio.stream.ImageInputStream;
 import javax.imageio.stream.ImageOutputStream;
-import sun.awt.AppContext;
 
 /**
  * A class containing static convenience methods for locating
@@ -108,9 +107,7 @@ public static void scanForPlugins() {
     // ImageInputStreams
 
     /**
-     * A class to hold information about caching.  Each
-     * {@code ThreadGroup} will have its own copy
-     * via the {@code AppContext} mechanism.
+     * A class to hold information about caching.
      */
     static class CacheInfo {
         boolean useCache = true;
@@ -144,17 +141,12 @@ public void setHasPermission(Boolean hasPermission) {
         }
     }
 
+    private static final CacheInfo info = new CacheInfo();
+
     /**
-     * Returns the {@code CacheInfo} object associated with this
-     * {@code ThreadGroup}.
+     * Returns the {@code CacheInfo} object.
      */
     private static synchronized CacheInfo getCacheInfo() {
-        AppContext context = AppContext.getAppContext();
-        CacheInfo info = (CacheInfo)context.get(CacheInfo.class);
-        if (info == null) {
-            info = new CacheInfo();
-            context.put(CacheInfo.class, info);
-        }
         return info;
     }