INT-4376: Upgage to Log4J 2 (#2321)

* INT-4376: Upgage to Log4J 2

JIRA: https://jira.spring.io/browse/INT-4376

* Deprecate Log4J 1.x components in favor of newly added
a `Log4j2LevelAdjuster` JUnit `@Rule`
* Update all the logging configuration to Log4J 2

* Polishing after testing

spring-integration-test-support/src/main/java/org/springframework/integration/test/rule/Log4j2LevelAdjuster.java

@@ -0,0 +1,216 @@
+/*
+ * Copyright 2018 the original author or authors.
+ *
+ * Licensed 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.springframework.integration.test.rule;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.stream.Stream;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.core.LoggerContext;
+import org.apache.logging.log4j.core.config.Configuration;
+import org.apache.logging.log4j.core.config.LoggerConfig;
+import org.junit.rules.MethodRule;
+import org.junit.runners.model.FrameworkMethod;
+import org.junit.runners.model.Statement;
+
+import org.springframework.util.Assert;
+import org.springframework.util.ObjectUtils;
+
+/**
+ * A JUnit method {@link org.junit.Rule} that changes the Log4J 2 logger level for a set of classes
+ * or packages while a test method is running. Useful for performance or scalability tests
+ * where we don't want to generate a large log in a tight inner loop, or
+ * enabling debug logging for a test case.
+ *
+ * @author Artem Bilan
+ *
+ * @since 5.0.1
+ *
+ */
+public class Log4j2LevelAdjuster implements MethodRule {
+
+	private static final Log logger = LogFactory.getLog(Log4j2LevelAdjuster.class);
+
+	private final Class<?>[] classes;
+
+	private final Level level;
+
+	private final String[] categories;
+
+	private Log4j2LevelAdjuster(Level level) {
+		this(level, null, new String[] { "org.springframework.integration" });
+	}
+
+	private Log4j2LevelAdjuster(Level level, Class<?>[] classes, String[] categories) {
+		Assert.notNull(level, "'level' must be null");
+		this.level = level;
+		this.classes = classes != null ? classes : new Class<?>[0];
+
+		Stream<String> categoryStream = Stream.of(getClass().getPackage().getName());
+
+		if (!ObjectUtils.isEmpty(categories)) {
+			categoryStream = Stream.concat(Arrays.stream(categories), categoryStream);
+		}
+
+		this.categories = categoryStream.toArray(String[]::new);
+	}
+
+	@Override
+	public Statement apply(final Statement base, final FrameworkMethod method, Object target) {
+		return new Statement() {
+
+			@Override
+			public void evaluate() throws Throwable {
+				LoggerContext ctx = (LoggerContext) LogManager.getContext(false);
+				Configuration config = ctx.getConfiguration();
+
+				Map<Class<?>, Level> classLevels = new HashMap<>();
+				for (Class<?> cls : Log4j2LevelAdjuster.this.classes) {
+					String className = cls.getName();
+					LoggerConfig loggerConfig = config.getLoggerConfig(className);
+					LoggerConfig specificConfig = loggerConfig;
+
+					// We need a specific configuration for this logger,
+					// otherwise we would change the level of all other loggers
+					// having the original configuration as parent as well
+
+					if (!loggerConfig.getName().equals(className)) {
+						specificConfig = new LoggerConfig(className, Log4j2LevelAdjuster.this.level, true);
+						specificConfig.setParent(loggerConfig);
+						config.addLogger(className, specificConfig);
+					}
+
+					classLevels.put(cls, specificConfig.getLevel());
+					specificConfig.setLevel(Log4j2LevelAdjuster.this.level);
+				}
+
+				Map<String, Level> categoryLevels = new HashMap<>();
+				for (String category : Log4j2LevelAdjuster.this.categories) {
+					LoggerConfig loggerConfig = config.getLoggerConfig(category);
+					LoggerConfig specificConfig = loggerConfig;
+
+					// We need a specific configuration for this logger,
+					// otherwise we would change the level of all other loggers
+					// having the original configuration as parent as well
+
+					if (!loggerConfig.getName().equals(category)) {
+						specificConfig = new LoggerConfig(category, Log4j2LevelAdjuster.this.level, true);
+						specificConfig.setParent(loggerConfig);
+						config.addLogger(category, specificConfig);
+					}
+
+					categoryLevels.put(category, specificConfig.getLevel());
+					specificConfig.setLevel(Log4j2LevelAdjuster.this.level);
+				}
+
+				ctx.updateLoggers();
+
+				logger.debug("++++++++++++++++++++++++++++ "
+						+ "Overridden log level setting for: " + Arrays.toString(Log4j2LevelAdjuster.this.classes)
+						+ " and " + Arrays.toString(Log4j2LevelAdjuster.this.categories)
+						+ " for test " + method.getName());
+
+				try {
+					base.evaluate();
+				}
+				finally {
+					logger.debug("++++++++++++++++++++++++++++ "
+							+ "Restoring log level setting for: " + Arrays.toString(Log4j2LevelAdjuster.this.classes)
+							+ " and " + Arrays.toString(Log4j2LevelAdjuster.this.categories)
+							+ " for test " + method.getName());
+
+					for (Class<?> cls : Log4j2LevelAdjuster.this.classes) {
+						LoggerConfig loggerConfig = config.getLoggerConfig(cls.getName());
+						loggerConfig.setLevel(classLevels.get(cls));
+					}
+
+					for (String category : Log4j2LevelAdjuster.this.categories) {
+						LoggerConfig loggerConfig = config.getLoggerConfig(category);
+						loggerConfig.setLevel(categoryLevels.get(category));
+					}
+
+					ctx.updateLoggers();
+				}
+			}
+
+		};
+	}
+
+	/**
+	 * Specify the classes for logging level adjusting configured before.
+	 * A new copy Log4j2LevelAdjuster instance is produced by this method.
+	 * The provided classes parameter overrides existing value in the {@link #classes}.
+	 * @param classes the classes to use for logging level adjusting
+	 * @return a Log4j2LevelAdjuster copy with the provided classes
+	 */
+	public Log4j2LevelAdjuster classes(Class<?>... classes) {
+		return new Log4j2LevelAdjuster(this.level, classes, this.categories);
+	}
+
+	/**
+	 * Specify the categories for logging level adjusting configured before.
+	 * A new copy Log4j2LevelAdjuster instance is produced by this method.
+	 * The provided categories parameter overrides existing value in the {@link #categories}.
+	 * @param categories the categories to use for logging level adjusting
+	 * @return a Log4j2LevelAdjuster copy with the provided categories
+	 */
+	public Log4j2LevelAdjuster categories(String... categories) {
+		return new Log4j2LevelAdjuster(this.level, this.classes, categories);
+	}
+
+	/**
+	 * The factory to produce Log4j2LevelAdjuster instances for {@link Level#TRACE} logging
+	 * with the {@code org.springframework.integration} as default category.
+	 * @return the Log4j2LevelAdjuster instance
+	 */
+	public static Log4j2LevelAdjuster trace() {
+		return level(Level.TRACE);
+	}
+
+	/**
+	 * The factory to produce Log4j2LevelAdjuster instances for {@link Level#DEBUG} logging
+	 * with the {@code org.springframework.integration} as default category.
+	 * @return the Log4j2LevelAdjuster instance
+	 */
+	public static Log4j2LevelAdjuster debug() {
+		return level(Level.DEBUG);
+	}
+
+	/**
+	 * The factory to produce Log4j2LevelAdjuster instances for {@link Level#INFO} logging
+	 * with the {@code org.springframework.integration} as default category.
+	 * @return the Log4j2LevelAdjuster instance
+	 */
+	public static Log4j2LevelAdjuster info() {
+		return level(Level.INFO);
+	}
+
+	/**
+	 * The factory to produce Log4j2LevelAdjuster instances for arbitrary logging {@link Level}
+	 * with the {@code org.springframework.integration} as default category.
+	 * @return the Log4j2LevelAdjuster instance
+	 */
+	public static Log4j2LevelAdjuster level(Level level) {
+		return new Log4j2LevelAdjuster(level);
+	}
+
+}

spring-integration-test-support/src/main/java/org/springframework/integration/test/rule/Log4jLevelAdjuster.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2016 the original author or authors.
+ * Copyright 2015-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -41,10 +41,16 @@ import org.junit.runners.model.Statement;
  * @author Dave Syer
  * @author Gary Russell
  *
+ * @deprecated since 5.0.1 in favor of {@link Log4j2LevelAdjuster}.
+ * Will be removed in 5.1.
+ *
  */
+@Deprecated
+@SuppressWarnings("deprecation")
 public class Log4jLevelAdjuster implements MethodRule {
 
-	private static final Log logger = LogFactory.getLog(Log4jLevelAdjuster.class);
+	private static final Log logger =
+			LogFactory.getLog(org.springframework.integration.test.rule.Log4jLevelAdjuster.class);
 
 	private final Class<?>[] classes;
 

spring-integration-test-support/src/main/java/org/springframework/integration/test/support/LogAdjustingTestSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2016 the original author or authors.
+ * Copyright 2015-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -40,7 +40,11 @@ import org.junit.rules.TestName;
  *
  * @since 4.2.2
  *
+ * @deprecated since 5.0.1 in favor of {@link org.springframework.integration.test.rule.Log4j2LevelAdjuster}.
+ * Will be removed in 5.1.
+ *
  */
+@Deprecated
 public class LogAdjustingTestSupport {
 
 	/*

spring-integration-test-support/src/test/resources/log4j.properties

@@ -1,7 +0,0 @@
-log4j.rootCategory=WARN, stdout
-
-log4j.appender.stdout=org.apache.log4j.ConsoleAppender
-log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
-log4j.appender.stdout.layout.ConversionPattern=%c{1}: %m%n
-
-log4j.category.org.springframework.integration=WARN

spring-integration-test-support/src/test/resources/log4j2-test.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+	<Appenders>
+		<Console name="STDOUT" target="SYSTEM_OUT">
+			<PatternLayout pattern="%d %p [%t] [%c] - %m%n" />
+		</Console>
+	</Appenders>
+	<Loggers>
+		<Logger name="org.springframework.integration" level="warn"/>
+		<Root level="warn">
+			<AppenderRef ref="STDOUT" />
+		</Root>
+	</Loggers>
+</Configuration>