Add JPL to Log4j API bridge

jpl-to-log4j-api/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ 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.
+  -->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>org.apache.logging.log4j</groupId>
+    <artifactId>log4j-jdk-parent</artifactId>
+    <version>${revision}</version>
+    <relativePath>../parent</relativePath>
+  </parent>
+
+  <artifactId>jpl-to-log4j-api</artifactId>
+  <name>JPL to Log4j API logging bridge</name>
+  <description>The Apache Log4j implementation of java.lang.System.LoggerFinder</description>
+
+  <properties>
+    <!-- Skips BND Baseline until the first release -->
+    <bnd.baseline.fail.on.missing>false</bnd.baseline.fail.on.missing>
+
+    <module.name>org.apache.logging.jpl.log4j.api</module.name>
+    <maven.compiler.release>11</maven.compiler.release>
+  </properties>
+
+  <dependencies>
+
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-api</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-core</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-core-test</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>org.hamcrest</groupId>
+      <artifactId>hamcrest</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-engine</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+  </dependencies>
+
+</project>

jpl-to-log4j-api/src/main/java/org/apache/logging/log4j/jpl/Log4jSystemLogger.java

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+/*
+ * 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.jpl;
+
+import java.lang.System.Logger;
+import java.util.MissingResourceException;
+import java.util.Objects;
+import java.util.ResourceBundle;
+import java.util.function.Supplier;
+import org.apache.logging.log4j.message.Message;
+import org.apache.logging.log4j.message.MessageFormatMessage;
+import org.apache.logging.log4j.message.SimpleMessage;
+import org.apache.logging.log4j.spi.ExtendedLogger;
+
+/**
+ * JPL {@link Logger logger} implementation that uses Log4j.
+ * Implement all default {@link Logger} methods to ensure proper class resolution
+ *
+ * @since 2.14
+ */
+public class Log4jSystemLogger implements Logger {
+
+    private final ExtendedLogger logger;
+
+    private static final String FQCN = Log4jSystemLogger.class.getName();
+
+    public Log4jSystemLogger(final ExtendedLogger logger) {
+        this.logger = logger;
+    }
+
+    @Override
+    public String getName() {
+        return logger.getName();
+    }
+
+    @Override
+    public boolean isLoggable(final Level level) {
+        return logger.isEnabled(getLevel(level));
+    }
+
+    @Override
+    public void log(final Level level, final String msg) {
+        log(level, (ResourceBundle) null, msg, (Throwable) null);
+    }
+
+    @Override
+    public void log(final Level level, final Supplier<String> msgSupplier) {
+        Objects.requireNonNull(msgSupplier);
+        if (isLoggable(Objects.requireNonNull(level))) {
+            log(level, (ResourceBundle) null, msgSupplier.get(), (Throwable) null);
+        }
+    }
+
+    @Override
+    public void log(final Level level, final Object obj) {
+        Objects.requireNonNull(obj);
+        if (isLoggable(Objects.requireNonNull(level))) {
+            log(level, (ResourceBundle) null, obj.toString(), (Throwable) null);
+        }
+    }
+
+    @Override
+    public void log(final Level level, final String msg, final Throwable thrown) {
+        log(level, null, msg, thrown);
+    }
+
+    @Override
+    public void log(final Level level, final Supplier<String> msgSupplier, final Throwable thrown) {
+        Objects.requireNonNull(msgSupplier);
+        if (isLoggable(Objects.requireNonNull(level))) {
+            log(level, null, msgSupplier.get(), thrown);
+        }
+    }
+
+    @Override
+    public void log(final Level level, final String format, final Object... params) {
+        log(level, null, format, params);
+    }
+
+    @Override
+    public void log(final Level level, final ResourceBundle bundle, final String msg, final Throwable thrown) {
+        logger.logIfEnabled(FQCN, getLevel(level), null, getResource(bundle, msg), thrown);
+    }
+
+    @Override
+    public void log(final Level level, final ResourceBundle bundle, final String format, final Object... params) {
+        final Message message = createMessage(getResource(bundle, format), params);
+        logger.logIfEnabled(FQCN, getLevel(level), null, message, message.getThrowable());
+    }
+
+    private static Message createMessage(final String format, final Object... params) {
+        if (params == null || params.length == 0) {
+            return new SimpleMessage(format);
+        }
+        return new MessageFormatMessage(format, params);
+    }
+
+    private static org.apache.logging.log4j.Level getLevel(final Level level) {
+        switch (level) {
+            case OFF:
+                return org.apache.logging.log4j.Level.OFF;
+            case ERROR:
+                return org.apache.logging.log4j.Level.ERROR;
+            case WARNING:
+                return org.apache.logging.log4j.Level.WARN;
+            case INFO:
+                return org.apache.logging.log4j.Level.INFO;
+            case DEBUG:
+                return org.apache.logging.log4j.Level.DEBUG;
+            case TRACE:
+                return org.apache.logging.log4j.Level.TRACE;
+            case ALL:
+                return org.apache.logging.log4j.Level.ALL;
+        }
+        return org.apache.logging.log4j.Level.ERROR;
+    }
+
+    private static String getResource(final ResourceBundle bundle, final String msg) {
+        if (bundle == null || msg == null) {
+            return msg;
+        }
+        try {
+            return bundle.getString(msg);
+        } catch (MissingResourceException e) {
+            // ignore
+            return msg;
+        } catch (ClassCastException ex) {
+            return bundle.getObject(msg).toString();
+        }
+    }
+}

jpl-to-log4j-api/src/main/java/org/apache/logging/log4j/jpl/Log4jSystemLoggerAdapter.java

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+/*
+ * 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.jpl;
+
+import java.lang.System.Logger;
+import java.lang.System.LoggerFinder;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.spi.AbstractLoggerAdapter;
+import org.apache.logging.log4j.spi.LoggerContext;
+import org.apache.logging.log4j.util.StackLocatorUtil;
+
+/**
+ * {@link Logger} registry implementation using just log4j-api.
+ *
+ * @since 2.14
+ */
+public class Log4jSystemLoggerAdapter extends AbstractLoggerAdapter<Logger> {
+
+    @Override
+    protected Logger newLogger(final String name, final LoggerContext context) {
+        return new Log4jSystemLogger(context.getLogger(name));
+    }
+
+    @Override
+    protected LoggerContext getContext() {
+        return getContext(
+                LogManager.getFactory().isClassLoaderDependent()
+                        ? StackLocatorUtil.getCallerClass(LoggerFinder.class)
+                        : null);
+    }
+}

jpl-to-log4j-api/src/main/java/org/apache/logging/log4j/jpl/Log4jSystemLoggerFinder.java

@@ -0,0 +1,35 @@
+/*
+ * 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.jpl;
+
+import aQute.bnd.annotation.Resolution;
+import aQute.bnd.annotation.spi.ServiceProvider;
+import java.lang.System.Logger;
+
+/**
+ * @since 2.14
+ */
+@ServiceProvider(value = System.LoggerFinder.class, resolution = Resolution.OPTIONAL)
+public class Log4jSystemLoggerFinder extends System.LoggerFinder {
+
+    private final Log4jSystemLoggerAdapter loggerAdapter = new Log4jSystemLoggerAdapter();
+
+    @Override
+    public Logger getLogger(final String name, final Module module) {
+        return loggerAdapter.getLogger(name);
+    }
+}

jpl-to-log4j-api/src/main/java/org/apache/logging/log4j/jpl/package-info.java

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+/*
+ * 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.
+ */
+@Export
+@Version("2.20.1")
+package org.apache.logging.log4j.jpl;
+
+import org.osgi.annotation.bundle.Export;
+import org.osgi.annotation.versioning.Version;

jpl-to-log4j-api/src/main/resources/META-INF/services/java.lang.System$LoggerFinder

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+# 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.
+org.apache.logging.log4j.jpl.Log4jSystemLoggerFinder