Encapsulate class in log4j-jul

log4j-jul-propagator/src/main/java/org/apache/logging/log4j/jul/propagator/JulLevelPropagator.java

@@ -28,14 +28,14 @@
 import org.apache.logging.log4j.core.config.Configuration;
 import org.apache.logging.log4j.core.config.LoggerConfig;
 import org.apache.logging.log4j.jul.LevelTranslator;
-import org.apache.logging.log4j.jul.Log4jBridgeHandler;
+import org.apache.logging.log4j.jul.spi.LevelChangePropagator;
 import org.apache.logging.log4j.status.StatusLogger;
 
 /**
  * Propagates Log4j Core level to JUL.
  */
-@ServiceProvider(value = Log4jBridgeHandler.LevelPropagator.class)
-public class JulLevelPropagator implements Log4jBridgeHandler.LevelPropagator, Consumer<Configuration> {
+@ServiceProvider(value = LevelChangePropagator.class)
+public class JulLevelPropagator implements LevelChangePropagator, Consumer<Configuration> {
 
     private static final Logger LOGGER = StatusLogger.getLogger();
 

log4j-jul/src/main/java/org/apache/logging/log4j/jul/LevelTranslator.java

@@ -18,6 +18,9 @@
 
 import org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.jul.internal.DefaultLevelConverter;
+import org.apache.logging.log4j.jul.internal.JulProperties;
+import org.apache.logging.log4j.jul.spi.LevelConverter;
 import org.apache.logging.log4j.kit.env.PropertyEnvironment;
 import org.apache.logging.log4j.status.StatusLogger;
 import org.apache.logging.log4j.util.LoaderUtil;

log4j-jul/src/main/java/org/apache/logging/log4j/jul/Log4jBridgeHandler.java

@@ -23,6 +23,7 @@
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.util.ServiceLoader;
 import java.util.logging.LogRecord;
+import org.apache.logging.log4j.jul.spi.LevelChangePropagator;
 import org.apache.logging.log4j.spi.ExtendedLogger;
 import org.apache.logging.log4j.status.StatusLogger;
 import org.apache.logging.log4j.util.ServiceLoaderUtil;
@@ -64,7 +65,7 @@
  * @see <a href="https://logging.apache.org/log4j/3.x/log4j-jul.html">Log4j documentation site</a>
  * @since 2.15.0
  */
-@ServiceConsumer(value = Log4jBridgeHandler.LevelPropagator.class, cardinality = Cardinality.SINGLE)
+@ServiceConsumer(value = LevelChangePropagator.class, cardinality = Cardinality.SINGLE)
 public class Log4jBridgeHandler extends java.util.logging.Handler {
     private static final org.apache.logging.log4j.Logger LOGGER = StatusLogger.getLogger();
 
@@ -77,7 +78,7 @@ public class Log4jBridgeHandler extends java.util.logging.Handler {
 
     private boolean doDebugOutput = false;
     private String julSuffixToAppend = null;
-    private LevelPropagator levelPropagator;
+    private LevelChangePropagator levelPropagator;
     private volatile boolean installAsLevelPropagator = false;
 
     /**
@@ -135,8 +136,9 @@ private void configure(String suffixToAppend, boolean propagateLevels) {
         installAsLevelPropagator = propagateLevels;
         if (installAsLevelPropagator) {
             levelPropagator = ServiceLoaderUtil.safeStream(
-                            LevelPropagator.class,
-                            ServiceLoader.load(LevelPropagator.class, getClass().getClassLoader()),
+                            LevelChangePropagator.class,
+                            ServiceLoader.load(
+                                    LevelChangePropagator.class, getClass().getClassLoader()),
                             LOGGER)
                     .findAny()
                     .orElse(null);
@@ -216,30 +218,4 @@ private org.apache.logging.log4j.Logger getLog4jLogger(final LogRecord record) {
         }
         return org.apache.logging.log4j.LogManager.getLogger(name);
     }
-
-    /**
-     * Propagates level configuration from the Log4j API implementation used
-     * <p>
-     *     Using the {@link Log4jBridgeHandler} is expensive, since disabled log events must be formatted by JUL,
-     *     before they can be dropped by the Log4j API implementation.
-     * </p>
-     * <p>
-     *     This class introduces a mechanism that can be implemented by each Log4j API implementation to be notified,
-     *     whenever a {@link Log4jBridgeHandler} is used. The logging implementation will be able to synchronize
-     *     its levels with the levels of JUL loggers each time it is reconfigured.
-     * </p>
-     * @since 3.0.0
-     */
-    public interface LevelPropagator {
-
-        /**
-         * Start propagating log levels.
-         */
-        void start();
-
-        /**
-         * Stop propagating log levels.
-         */
-        void stop();
-    }
 }

log4j-jul/src/main/java/org/apache/logging/log4j/jul/LogManager.java

@@ -21,6 +21,10 @@
 import java.util.HashSet;
 import java.util.Set;
 import java.util.logging.Logger;
+import org.apache.logging.log4j.jul.internal.ApiLoggerAdapter;
+import org.apache.logging.log4j.jul.internal.JulProperties;
+import org.apache.logging.log4j.jul.internal.NoOpLogger;
+import org.apache.logging.log4j.jul.spi.AbstractLoggerAdapter;
 import org.apache.logging.log4j.kit.env.PropertyEnvironment;
 import org.apache.logging.log4j.status.StatusLogger;
 import org.apache.logging.log4j.util.LoaderUtil;

log4j-jul/src/main/java/org/apache/logging/log4j/jul/internal/ApiLogger.java

@@ -0,0 +1,31 @@
+/*
+ * 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.jul.internal;
+
+import org.apache.logging.log4j.jul.support.AbstractLogger;
+import org.apache.logging.log4j.spi.ExtendedLogger;
+
+/**
+ * Implementation of {@link java.util.logging.Logger} that ignores all method calls that do not have an equivalent in
+ * the Log4j API.
+ */
+public class ApiLogger extends AbstractLogger {
+
+    public ApiLogger(ExtendedLogger logger) {
+        super(logger);
+    }
+}

log4j-jul/src/main/java/org/apache/logging/log4j/jul/ApiLoggerAdapter.java → log4j-jul/src/main/java/org/apache/logging/log4j/jul/internal/ApiLoggerAdapter.java

@@ -14,9 +14,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.logging.log4j.jul;
+package org.apache.logging.log4j.jul.internal;
 
 import java.util.logging.Logger;
+import org.apache.logging.log4j.jul.spi.AbstractLoggerAdapter;
 import org.apache.logging.log4j.message.MessageFactory;
 import org.apache.logging.log4j.message.MessageFormatMessageFactory;
 import org.apache.logging.log4j.spi.LoggerContext;
@@ -32,7 +33,7 @@ public class ApiLoggerAdapter extends AbstractLoggerAdapter {
     private static final MessageFactory MESSAGE_FACTORY = new MessageFormatMessageFactory();
 
     @Override
-    protected Logger newLogger(final String name, final LoggerContext context) {
+    public Logger newLogger(final String name, final LoggerContext context) {
         return new ApiLogger(context.getLogger(name, MESSAGE_FACTORY));
     }
 }

log4j-jul/src/main/java/org/apache/logging/log4j/jul/DefaultLevelConverter.java → log4j-jul/src/main/java/org/apache/logging/log4j/jul/internal/DefaultLevelConverter.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.logging.log4j.jul;
+package org.apache.logging.log4j.jul.internal;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -25,6 +25,8 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.jul.LevelTranslator;
+import org.apache.logging.log4j.jul.spi.LevelConverter;
 
 /**
  * Default implementation of LevelConverter strategy.

log4j-jul/src/main/java/org/apache/logging/log4j/jul/JulProperties.java → log4j-jul/src/main/java/org/apache/logging/log4j/jul/internal/JulProperties.java

@@ -14,8 +14,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.logging.log4j.jul;
+package org.apache.logging.log4j.jul.internal;
 
+import org.apache.logging.log4j.jul.spi.AbstractLoggerAdapter;
+import org.apache.logging.log4j.jul.spi.LevelConverter;
 import org.apache.logging.log4j.kit.env.Log4jProperty;
 import org.jspecify.annotations.Nullable;
 

log4j-jul/src/main/java/org/apache/logging/log4j/jul/NoOpLogger.java → log4j-jul/src/main/java/org/apache/logging/log4j/jul/internal/NoOpLogger.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.logging.log4j.jul;
+package org.apache.logging.log4j.jul.internal;
 
 import java.util.ResourceBundle;
 import java.util.function.Supplier;
@@ -27,7 +27,7 @@
  */
 public class NoOpLogger extends Logger {
 
-    protected NoOpLogger(final String name) {
+    public NoOpLogger(final String name) {
         super(name, null);
     }
 

log4j-jul/src/main/java/org/apache/logging/log4j/jul/AbstractLoggerAdapter.java → log4j-jul/src/main/java/org/apache/logging/log4j/jul/spi/AbstractLoggerAdapter.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.logging.log4j.jul;
+package org.apache.logging.log4j.jul.spi;
 
 import java.util.logging.Logger;
 import org.apache.logging.log4j.LogManager;
@@ -36,14 +36,29 @@
  *     If you wish to enable this feature again, you need to implement this class and provide its FQCN
  *     as {@code log4j.jul.loggerAdapter} configuration property.
  * </p>
+ * <p>
+ *     <strong>Implementation note:</strong> since version 3.0.0, this interface was moved to a new package.
+ * </p>
  *
  * @see <a href="https://github.com/apache/logging-log4j2/issues/2353">Issue #2353</a>
  * @since 2.1
  */
 public abstract class AbstractLoggerAdapter extends org.apache.logging.log4j.spi.AbstractLoggerAdapter<Logger> {
 
+    /**
+     * Creates a new {@link java.util.logging.Logger}
+     * <p>
+     *     Each implementation should provide this method.
+     * </p>
+     */
+    @Override
+    public abstract Logger newLogger(String name, LoggerContext context);
+
+    /**
+     * Provides the most appropriate {@link LoggerContext} for the caller.
+     */
     @Override
-    protected LoggerContext getContext() {
+    public LoggerContext getContext() {
         return getContext(
                 LogManager.getFactory().isClassLoaderDependent()
                         ? StackLocatorUtil.getCallerClass(java.util.logging.LogManager.class)

log4j-jul/src/main/java/org/apache/logging/log4j/jul/spi/LevelChangePropagator.java

@@ -0,0 +1,45 @@
+/*
+ * 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.jul.spi;
+
+import org.apache.logging.log4j.jul.Log4jBridgeHandler;
+
+/**
+ * Propagates level configuration from the Log4j API implementation used
+ * <p>
+ *     Using the {@link Log4jBridgeHandler} is expensive, since disabled log events must be formatted by JUL,
+ *     before they can be dropped by the Log4j API implementation.
+ * </p>
+ * <p>
+ *     This class introduces a mechanism that can be implemented by each Log4j API implementation to be notified,
+ *     whenever a {@link Log4jBridgeHandler} is used. The logging implementation will be able to synchronize
+ *     its levels with the levels of JUL loggers each time it is reconfigured.
+ * </p>
+ * @since 3.0.0
+ */
+public interface LevelChangePropagator {
+
+    /**
+     * Start propagating log levels.
+     */
+    void start();
+
+    /**
+     * Stop propagating log levels.
+     */
+    void stop();
+}

log4j-jul/src/main/java/org/apache/logging/log4j/jul/LevelConverter.java → log4j-jul/src/main/java/org/apache/logging/log4j/jul/spi/LevelConverter.java

@@ -14,15 +14,18 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.logging.log4j.jul;
+package org.apache.logging.log4j.jul.spi;
 
 import org.apache.logging.log4j.Level;
 
 /**
  * Strategy interface to convert between custom Log4j {@link Level Levels} and JUL
  * {@link java.util.logging.Level Levels}.
+ * <p>
+ *     <strong>Implementation note:</strong> since version 3.0.0, this interface was moved to a new package.
+ * </p>
  *
- * @see JulProperties#levelConverter()
+ * @see org.apache.logging.log4j.jul.internal.JulProperties#levelConverter()
  * @since 2.1
  */
 public interface LevelConverter {

log4j-jul/src/main/java/org/apache/logging/log4j/jul/spi/package-info.java

@@ -0,0 +1,25 @@
+/*
+ * 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.
+ */
+/**
+ * Contains interfaces an abstract classes to extend the functionality of Log4j JUL Adapter.
+ */
+@Export
+@Version("3.0.0")
+package org.apache.logging.log4j.jul.spi;
+
+import org.osgi.annotation.bundle.Export;
+import org.osgi.annotation.versioning.Version;