Fix server crash when File-Based Debug Logger is enabled

opendj-core/src/main/java/org/forgerock/opendj/ldap/spi/LdapMessages.java

@@ -12,6 +12,7 @@
  * information: "Portions Copyright [year] [name of copyright owner]".
  *
  * Copyright 2016 ForgeRock AS.
+ * Portions Copyright 2026 3A Systems, LLC.
  */
 package org.forgerock.opendj.ldap.spi;
 
@@ -106,6 +107,13 @@ public static final class LdapResponseMessage extends LdapMessageEnvelope<Respon
         private LdapResponseMessage(final byte messageType, final int messageId, final Response content) {
             super(messageType, messageId, content);
         }
+
+        @Override
+        public String toString() {
+            return "LdapResponseMessage(messageType=" + getMessageType()
+                    + ", messageId=" + getMessageId()
+                    + ", content=" + getContent() + ")";
+        }
     }
 
     private static abstract class LdapMessageEnvelope<T> {

opendj-server-legacy/src/main/java/org/opends/server/core/LoggerConfigManager.java

@@ -13,6 +13,7 @@
  *
  * Copyright 2006-2008 Sun Microsystems, Inc.
  * Portions Copyright 2013-2016 ForgeRock AS.
+ * Portions Copyright 2026 3A Systems, LLC.
  */
 package org.opends.server.core;
 
@@ -109,8 +110,13 @@ private void changeJulLogLevel(final Level newLevel)
       {
         SLF4JBridgeHandler.removeHandlersForRootLogger();
         // This is needed to avoid major performance issue. See: http://www.slf4j.org/legacy.html#jul-to-slf4j
+        // Limit Grizzly JUL logging to FINE to prevent a ClassCastException in
+        // FilterChainContext.toString() (Grizzly bug) when debug logging is enabled.
+        // Grizzly 3.0.1 DefaultFilterChain.executeFilter() checks isLoggable(FINEST) but
+        // its FilterChainContext.toString() incorrectly casts the message to char[].
         LogManager.getLogManager().readConfiguration(
-                new ByteArrayInputStream((".level=" + newLevel).getBytes()));
+                new ByteArrayInputStream(
+                        (".level=" + newLevel + "\norg.glassfish.grizzly.level=FINE").getBytes()));
         SLF4JBridgeHandler.install();
         currentJulLogLevel = newLevel;
       }