Port log4j-mongodb4 changes from 2.x

log4j-core/src/main/java/org/apache/logging/log4j/core/appender/nosql/DefaultNoSqlObject.java

@@ -42,21 +42,25 @@ public void set(final String field, final Object value) {
 
     @Override
     public void set(final String field, final NoSqlObject<Map<String, Object>> value) {
-        this.map.put(field, value.unwrap());
+        this.map.put(field, value != null ? value.unwrap() : null);
     }
 
     @Override
     public void set(final String field, final Object[] values) {
-        this.map.put(field, Arrays.asList(values));
+        this.map.put(field, values != null ? Arrays.asList(values) : null);
     }
 
     @Override
     public void set(final String field, final NoSqlObject<Map<String, Object>>[] values) {
-        final List<Map<String, Object>> list = new ArrayList<>(values.length);
-        for (final NoSqlObject<Map<String, Object>> value : values) {
-            list.add(value.unwrap());
+        if (values == null) {
+            this.map.put(field, null);
+        } else {
+            final List<Map<String, Object>> list = new ArrayList<>(values.length);
+            for (final NoSqlObject<Map<String, Object>> value : values) {
+                list.add(value.unwrap());
+            }
+            this.map.put(field, list);
         }
-        this.map.put(field, list);
     }
 
     @Override

log4j-core/src/main/java/org/apache/logging/log4j/core/pattern/PatternFormatter.java

@@ -22,6 +22,12 @@
  *
  */
 public class PatternFormatter {
+
+    /**
+     * The empty array.
+     */
+    public static final PatternFormatter[] EMPTY_ARRAY = {};
+
     private final LogEventPatternConverter converter;
     private final FormattingInfo field;
     private final boolean skipFormattingInfo;

log4j-jul/pom.xml

@@ -71,6 +71,11 @@
       <artifactId>junit</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-core-test</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <build>

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

@@ -50,12 +50,9 @@ public class ApiLogger extends Logger {
         super(logger.getName(), null);
         final Level javaLevel = LevelTranslator.toJavaLevel(logger.getLevel());
         // "java.util.logging.LoggingPermission" "control"
-        AccessController.doPrivileged(new PrivilegedAction<Object>() {
-            @Override
-            public Object run() {
-                ApiLogger.super.setLevel(javaLevel);
-                return null;
-            }
+        AccessController.doPrivileged((PrivilegedAction<Object>) () -> {
+            ApiLogger.super.setLevel(javaLevel);
+            return null;
         });
         this.logger = new WrappedLogger(logger);
     }

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

@@ -17,7 +17,6 @@
 package org.apache.logging.log4j.jul;
 
 // note: NO import of Logger, Level, LogManager to prevent conflicts JUL/log4j
-
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.util.Enumeration;
 import java.util.HashSet;
@@ -93,7 +92,7 @@ public class Log4jBridgeHandler extends java.util.logging.Handler implements Con
 
     private boolean doDebugOutput = false;
     private String julSuffixToAppend = null;
-    private LoggerContext context;
+    private volatile boolean installAsLevelPropagator = false;
 
     /**
      * Adds a new Log4jBridgeHandler instance to JUL's root logger.
@@ -153,14 +152,7 @@ protected void init(boolean debugOutput, String suffixToAppend, boolean propagat
         }
         this.julSuffixToAppend = suffixToAppend;
 
-        this.context = LoggerContext.getContext(false);
-
-        if (propagateLevels) {
-            context.addConfigurationStartedListener(this);
-            propagateLogLevels(context.getConfiguration());
-            // note: java.util.logging.LogManager.addPropertyChangeListener() could also
-            // be set here, but a call of JUL.readConfiguration() will be done on purpose
-        }
+        this.installAsLevelPropagator = propagateLevels;
 
         SLOGGER.debug(
                 "Log4jBridgeHandler init. with: suffix='{}', lvlProp={}, instance={}",
@@ -173,10 +165,7 @@ protected void init(boolean debugOutput, String suffixToAppend, boolean propagat
     public void close() {
         // cleanup and remove listener and JUL logger references
         julLoggerRefs = null;
-        if (context != null) {
-            context.removeConfigurationStartedListener(this);
-            context = null;
-        }
+        LoggerContext.getContext(false).removeConfigurationStartedListener(this);
         if (doDebugOutput) {
             System.out.println("sysout:  Log4jBridgeHandler close(): " + this);
         }
@@ -188,6 +177,23 @@ public void publish(final LogRecord record) {
             return;
         }
 
+        // Only execute synchronized code if we really have to
+        if (this.installAsLevelPropagator) {
+            synchronized (this) {
+                // Check again to make sure we still have to propagate  the levels at this point
+                if (this.installAsLevelPropagator) {
+                    // no need to close the AutoCloseable ctx here
+                    @SuppressWarnings("resource")
+                    final LoggerContext context = LoggerContext.getContext(false);
+                    context.addConfigurationStartedListener(this);
+                    propagateLogLevels(context.getConfiguration());
+                    // note: java.util.logging.LogManager.addPropertyChangeListener() could also
+                    // be set here, but a call of JUL.readConfiguration() will be done on purpose
+                    this.installAsLevelPropagator = false;
+                }
+            }
+        }
+
         final org.apache.logging.log4j.Logger log4jLogger = getLog4jLogger(record);
         final String msg = julFormatter.formatMessage(record); // use JUL's implementation to get real msg
         /* log4j allows nulls:

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

@@ -49,7 +49,6 @@ public class LogManager extends java.util.logging.LogManager {
     private final ThreadLocal<Set<String>> recursive = ThreadLocal.withInitial(HashSet::new);
 
     public LogManager() {
-        super();
         AbstractLoggerAdapter adapter = null;
         final String overrideAdaptorClassName =
                 PropertiesUtil.getProperties().getStringProperty(JulPropertyKey.LOGGER_ADAPTER);
@@ -99,10 +98,9 @@ public Logger getLogger(final String name) {
             } finally {
                 activeRequests.remove(name);
             }
-        } else {
-            LOGGER.warn("Recursive call to getLogger for {} ignored.", name);
-            return new NoOpLogger(name);
         }
+        LOGGER.warn("Recursive call to getLogger for {} ignored.", name);
+        return new NoOpLogger(name);
     }
 
     @Override

log4j-jul/src/test/java/org/apache/logging/log4j/jul/test/AbstractLoggerTest.java

@@ -23,6 +23,7 @@
 import org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.core.LogEvent;
 import org.apache.logging.log4j.core.impl.MementoLogEvent;
+import org.apache.logging.log4j.core.test.appender.ListAppender;
 import org.apache.logging.log4j.jul.ApiLogger;
 import org.apache.logging.log4j.jul.LevelTranslator;
 import org.junit.Test;

log4j-jul/src/test/java/org/apache/logging/log4j/jul/test/ApiLoggerTest.java

@@ -22,6 +22,7 @@
 import static org.junit.Assert.assertThat;
 
 import java.util.logging.Logger;
+import org.apache.logging.log4j.core.test.appender.ListAppender;
 import org.apache.logging.log4j.jul.ApiLoggerAdapter;
 import org.apache.logging.log4j.jul.JulPropertyKey;
 import org.apache.logging.log4j.jul.LogManager;

log4j-jul/src/test/java/org/apache/logging/log4j/jul/test/AsyncLoggerThreadsTest.java

@@ -23,13 +23,13 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.core.async.AsyncLoggerContextSelector;
 import org.apache.logging.log4j.core.impl.Log4jPropertyKey;
+import org.apache.logging.log4j.core.test.categories.AsyncLoggers;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
-import org.junit.Ignore;
 import org.junit.Test;
+import org.junit.experimental.categories.Category;
 
-// @Category(AsyncLoggers.class)
-@Ignore("https://issues.apache.org/jira/browse/LOG4J2-3523")
+@Category(AsyncLoggers.class)
 public class AsyncLoggerThreadsTest {
 
     @BeforeClass

log4j-jul/src/test/java/org/apache/logging/log4j/jul/test/BracketInNotInterpolatedMessageTest.java

@@ -24,6 +24,7 @@
 import java.util.logging.LogRecord;
 import java.util.logging.Logger;
 import org.apache.logging.log4j.core.LogEvent;
+import org.apache.logging.log4j.core.test.appender.ListAppender;
 import org.apache.logging.log4j.jul.LogManager;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;

log4j-jul/src/test/java/org/apache/logging/log4j/jul/test/CallerInformationTest.java

@@ -16,26 +16,25 @@
  */
 package org.apache.logging.log4j.jul.test;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
 
-import java.net.URI;
 import java.util.List;
 import java.util.logging.Logger;
-import org.apache.logging.log4j.core.LoggerContext;
+import org.apache.logging.log4j.core.test.appender.ListAppender;
+import org.apache.logging.log4j.core.test.junit.LoggerContextRule;
 import org.apache.logging.log4j.jul.LogManager;
-import org.junit.After;
 import org.junit.AfterClass;
-import org.junit.Before;
 import org.junit.BeforeClass;
+import org.junit.Rule;
 import org.junit.Test;
 
 public class CallerInformationTest {
 
     // config from log4j-core test-jar
     private static final String CONFIG = "log4j2-calling-class.xml";
 
-    private LoggerContext ctx;
-    private ListAppender app;
+    @Rule
+    public final LoggerContextRule ctx = new LoggerContextRule(CONFIG);
 
     @BeforeClass
     public static void setUpClass() {
@@ -47,27 +46,9 @@ public static void tearDownClass() {
         System.clearProperty("java.util.logging.manager");
     }
 
-    @Before
-    public void beforeEach() throws Exception {
-        final URI uri = this.getClass().getClassLoader().getResource(CONFIG).toURI();
-        ctx = (LoggerContext) org.apache.logging.log4j.LogManager.getContext(null, false, uri);
-        assertNotNull("No LoggerContext", ctx);
-    }
-
-    @After
-    public void afterEach() throws Exception {
-        if (ctx != null) {
-            ctx.stop();
-            ctx = null;
-            app = null;
-        }
-    }
-
     @Test
     public void testClassLogger() throws Exception {
-        app = ctx.getConfiguration().getAppender("Class");
-        assertNotNull("No ListAppender", app);
-        app.clear();
+        final ListAppender app = ctx.getListAppender("Class").clear();
         final Logger logger = Logger.getLogger("ClassLogger");
         logger.info("Ignored message contents.");
         logger.warning("Verifying the caller class is still correct.");
@@ -81,9 +62,7 @@ public void testClassLogger() throws Exception {
 
     @Test
     public void testMethodLogger() throws Exception {
-        app = ctx.getConfiguration().getAppender("Method");
-        assertNotNull("No ListAppender", app);
-        app.clear();
+        final ListAppender app = ctx.getListAppender("Method").clear();
         final Logger logger = Logger.getLogger("MethodLogger");
         logger.info("More messages.");
         logger.warning("CATASTROPHE INCOMING!");

log4j-jul/src/test/java/org/apache/logging/log4j/jul/test/CoreLoggerTest.java

@@ -23,6 +23,7 @@
 
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import org.apache.logging.log4j.core.test.appender.ListAppender;
 import org.apache.logging.log4j.jul.LogManager;
 import org.apache.logging.log4j.util.Strings;
 import org.junit.After;