Merge branch '2.0.x'

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/Slf4JLoggingSystem.java

@@ -48,7 +48,10 @@ public abstract class Slf4JLoggingSystem extends AbstractLoggingSystem {
 
 	@Override
 	public void cleanUp() {
+		if (isBridgeHandlerAvailable()) {
 			removeJdkLoggingBridgeHandler();
+			reinstateConsoleHandlerIfNecessary();
+		}
 	}
 
 	@Override
@@ -62,7 +65,7 @@ public abstract class Slf4JLoggingSystem extends AbstractLoggingSystem {
 
 	private void configureJdkLoggingBridgeHandler() {
 		try {
-			if (isBridgeHandlerAvailable()) {
+			if (isBridgeJulIntoSlf4j()) {
 				removeJdkLoggingBridgeHandler();
 				SLF4JBridgeHandler.install();
 			}
@@ -72,17 +75,25 @@ public abstract class Slf4JLoggingSystem extends AbstractLoggingSystem {
 		}
 	}
 
+	protected final boolean isBridgeJulIntoSlf4j() {
+		return isBridgeHandlerAvailable() && isJulUsingItsDefaultConfiguration();
+	}
+
 	protected final boolean isBridgeHandlerAvailable() {
 		return ClassUtils.isPresent(BRIDGE_HANDLER, getClassLoader());
 	}
 
+	private boolean isJulUsingItsDefaultConfiguration() {
+		Logger rootLogger = LogManager.getLogManager().getLogger("");
+		Handler[] handlers = rootLogger.getHandlers();
+		return handlers.length == 1 && handlers[0] instanceof ConsoleHandler;
+	}
+
 	private void removeJdkLoggingBridgeHandler() {
 		try {
-			if (isBridgeHandlerAvailable()) {
 			removeDefaultRootHandler();
 			SLF4JBridgeHandler.uninstall();
 		}
-		}
 		catch (Throwable ex) {
 			// Ignore and continue
 		}
@@ -101,4 +112,11 @@ public abstract class Slf4JLoggingSystem extends AbstractLoggingSystem {
 		}
 	}
 
+	private void reinstateConsoleHandlerIfNecessary() {
+		Logger rootLogger = LogManager.getLogManager().getLogger("");
+		if (rootLogger.getHandlers().length == 0) {
+			rootLogger.addHandler(new ConsoleHandler());
+		}
+	}
+
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/logback/LogbackLoggingSystem.java

@@ -22,6 +22,8 @@ import java.security.ProtectionDomain;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
+import java.util.logging.Handler;
+import java.util.logging.LogManager;
 
 import ch.qos.logback.classic.Level;
 import ch.qos.logback.classic.LoggerContext;
@@ -35,6 +37,7 @@ import ch.qos.logback.core.status.Status;
 import org.slf4j.ILoggerFactory;
 import org.slf4j.Logger;
 import org.slf4j.Marker;
+import org.slf4j.bridge.SLF4JBridgeHandler;
 import org.slf4j.impl.StaticLoggerBinder;
 
 import org.springframework.boot.logging.LogFile;
@@ -184,11 +187,20 @@ public class LogbackLoggingSystem extends Slf4JLoggingSystem {
 	private void stopAndReset(LoggerContext loggerContext) {
 		loggerContext.stop();
 		loggerContext.reset();
-		if (isBridgeHandlerAvailable()) {
+		if (isBridgeHandlerInstalled()) {
 			addLevelChangePropagator(loggerContext);
 		}
 	}
 
+	private boolean isBridgeHandlerInstalled() {
+		if (!isBridgeHandlerAvailable()) {
+			return false;
+		}
+		java.util.logging.Logger rootLogger = LogManager.getLogManager().getLogger("");
+		Handler[] handlers = rootLogger.getHandlers();
+		return handlers.length == 1 && SLF4JBridgeHandler.class.isInstance(handlers[0]);
+	}
+
 	private void addLevelChangePropagator(LoggerContext loggerContext) {
 		LevelChangePropagator levelChangePropagator = new LevelChangePropagator();
 		levelChangePropagator.setResetJUL(true);

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/logging/log4j2/Log4J2LoggingSystemTests.java

@@ -32,6 +32,7 @@ import org.apache.logging.log4j.core.LoggerContext;
 import org.apache.logging.log4j.core.config.Configuration;
 import org.hamcrest.Matcher;
 import org.hamcrest.Matchers;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -77,6 +78,13 @@ public class Log4J2LoggingSystemTests extends AbstractLoggingSystemTests {
 		this.logger = LogManager.getLogger(getClass());
 	}
 
+	@Override
+	@After
+	public void clear() {
+		super.clear();
+		this.loggingSystem.cleanUp();
+	}
+
 	@Test
 	public void noFile() {
 		this.loggingSystem.beforeInitialize();

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/logging/logback/LogbackLoggingSystemTests.java

@@ -104,6 +104,7 @@ public class LogbackLoggingSystemTests extends AbstractLoggingSystemTests {
 	@Override
 	@After
 	public void clear() {
+		super.clear();
 		this.loggingSystem.cleanUp();
 	}