Backport the InternalApi annotation

Signed-off-by: Matt Sicker <[email protected]>

Author: jvz

log4j-api/src/main/java/org/apache/logging/log4j/util/Activator.java

@@ -48,6 +48,7 @@
  */
 @Header(name = Constants.BUNDLE_ACTIVATOR, value = "${@class}")
 @Header(name = Constants.BUNDLE_ACTIVATIONPOLICY, value = Constants.ACTIVATION_LAZY)
+@InternalApi
 public class Activator implements BundleActivator, SynchronousBundleListener {
 
     private static final SecurityManager SECURITY_MANAGER = System.getSecurityManager();

log4j-api/src/main/java/org/apache/logging/log4j/util/Chars.java

@@ -19,6 +19,7 @@
 /**
  * <em>Consider this class private.</em>
  */
+@InternalApi
 public final class Chars {
 
     /** Carriage Return. */

log4j-api/src/main/java/org/apache/logging/log4j/util/EnglishEnums.java

@@ -30,6 +30,7 @@
  * avoid problems on the Turkish locale. Do not use with Turkish enum values.
  * </p>
  */
+@InternalApi
 public final class EnglishEnums {
 
     private EnglishEnums() {

log4j-api/src/main/java/org/apache/logging/log4j/util/InternalApi.java

@@ -0,0 +1,32 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to you under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.logging.log4j.util;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/**
+ * Indicates that the annotated element is considered an internal API to Log4j and should not be used by external
+ * code. Internal APIs do not provide any stability guarantees between versions.
+ *
+ * @since 2.22.0
+ */
+@Retention(RetentionPolicy.CLASS)
+@Documented
+public @interface InternalApi {
+}

log4j-api/src/main/java/org/apache/logging/log4j/util/ProviderUtil.java

@@ -38,6 +38,7 @@
  * container framework, any Log4j Providers not accessible through standard classpath scanning should
  * {@link #loadProvider(java.net.URL, ClassLoader)} a classpath accordingly.
  */
+@InternalApi
 @ServiceConsumer(value = Provider.class, resolution = Resolution.OPTIONAL, cardinality = Cardinality.MULTIPLE)
 public final class ProviderUtil {
 

log4j-api/src/main/java/org/apache/logging/log4j/util/ServiceLoaderUtil.java

@@ -40,6 +40,7 @@
 /**
  * This class should be considered internal.
  */
+@InternalApi
 public final class ServiceLoaderUtil {
 
     private static final int MAX_BROKEN_SERVICES = 8;

log4j-api/src/main/java/org/apache/logging/log4j/util/SortedArrayStringMap.java

@@ -50,6 +50,7 @@
  *
  * @since 2.7
  */
+@InternalApi
 public class SortedArrayStringMap implements IndexedStringMap {
 
     /**

log4j-api/src/main/java/org/apache/logging/log4j/util/StackLocator.java

@@ -46,6 +46,7 @@
  * examination of every virtual frame of execution.
  * </p>
  */
+@InternalApi
 public final class StackLocator {
 
     /** TODO Consider removing now that we require Java 8. */

log4j-api/src/main/java/org/apache/logging/log4j/util/StackLocatorUtil.java

@@ -25,6 +25,7 @@
 /**
  * <em>Consider this class private.</em> Provides various methods to determine the caller class. <h3>Background</h3>
  */
+@InternalApi
 public final class StackLocatorUtil {
     private static StackLocator stackLocator = null;
     private static volatile boolean errorLogged;

log4j-api/src/main/java/org/apache/logging/log4j/util/StringBuilders.java

@@ -23,6 +23,7 @@
 /**
  * <em>Consider this class private.</em>
  */
+@InternalApi
 public final class StringBuilders {
 
     private static final Class<?> timeClass;