Support programmatic setting of log levels

Provide a common way to programmatically set log levels regardless of
the underlying log implementation.

Issue: #55202588

spring-boot/pom.xml

@@ -39,6 +39,11 @@
 			<artifactId>javax.servlet-api</artifactId>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>log4j</groupId>
+			<artifactId>log4j</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.apache.tomcat.embed</groupId>
 			<artifactId>tomcat-embed-core</artifactId>

spring-boot/src/main/java/org/springframework/boot/logging/LogLevel.java

+/*
+ * Copyright 2012-2013 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.boot.logging;
+
+/**
+ * Logging levels supported by a {@link LoggingSystem}.
+ * 
+ * @author Phillip Webb
+ */
+public enum LogLevel {
+
+	TRACE, DEBUG, INFO, WARN, ERROR, FATAL
+
+}

spring-boot/src/main/java/org/springframework/boot/logging/LoggingSystem.java

@@ -61,6 +61,13 @@ public abstract class LoggingSystem {
 	 */
 	public abstract void initialize(String configLocation);
 
+	/**
+	 * Sets the logging level for a given logger.
+	 * @param loggerName the name of the logger to set
+	 * @param level the log level
+	 */
+	public abstract void setLogLevel(String loggerName, LogLevel level);
+
 	/**
 	 * Detect and return the logging system in use.
 	 * @return The logging system

spring-boot/src/main/java/org/springframework/boot/logging/java/JavaLoggingSystem.java

@@ -16,11 +16,17 @@
 
 package org.springframework.boot.logging.java;
 
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.logging.Level;
 import java.util.logging.LogManager;
 import java.util.logging.Logger;
 
 import org.springframework.boot.logging.AbstractLoggingSystem;
+import org.springframework.boot.logging.LogLevel;
 import org.springframework.boot.logging.LoggingSystem;
+import org.springframework.util.Assert;
 import org.springframework.util.ResourceUtils;
 import org.springframework.util.SystemPropertyUtils;
 
@@ -32,12 +38,25 @@ import org.springframework.util.SystemPropertyUtils;
  */
 public class JavaLoggingSystem extends AbstractLoggingSystem {
 
+	private static final Map<LogLevel, Level> LEVELS;
+	static {
+		Map<LogLevel, Level> levels = new HashMap<LogLevel, Level>();
+		levels.put(LogLevel.TRACE, Level.FINEST);
+		levels.put(LogLevel.DEBUG, Level.FINE);
+		levels.put(LogLevel.INFO, Level.INFO);
+		levels.put(LogLevel.WARN, Level.WARNING);
+		levels.put(LogLevel.ERROR, Level.SEVERE);
+		levels.put(LogLevel.FATAL, Level.SEVERE);
+		LEVELS = Collections.unmodifiableMap(levels);
+	}
+
 	public JavaLoggingSystem(ClassLoader classLoader) {
 		super(classLoader, "logging.properties");
 	}
 
 	@Override
 	public void initialize(String configLocation) {
+		Assert.notNull(configLocation, "ConfigLocation must not be null");
 		String resolvedLocation = SystemPropertyUtils.resolvePlaceholders(configLocation);
 		try {
 			LogManager.getLogManager().readConfiguration(
@@ -49,4 +68,10 @@ public class JavaLoggingSystem extends AbstractLoggingSystem {
 		}
 	}
 
+	@Override
+	public void setLogLevel(String loggerName, LogLevel level) {
+		Assert.notNull(level, "Level must not be null");
+		Logger logger = Logger.getLogger(loggerName == null ? "" : loggerName);
+		logger.setLevel(LEVELS.get(level));
+	}
 }

spring-boot/src/main/java/org/springframework/boot/logging/log4j/Log4JLoggingSystem.java

@@ -16,9 +16,19 @@
 
 package org.springframework.boot.logging.log4j;
 
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.log4j.Level;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
 import org.springframework.boot.logging.AbstractLoggingSystem;
+import org.springframework.boot.logging.LogLevel;
 import org.springframework.boot.logging.LoggingSystem;
+import org.springframework.util.Assert;
 import org.springframework.util.Log4jConfigurer;
+import org.springframework.util.StringUtils;
 
 /**
  * {@link LoggingSystem} for for <a href="http://logging.apache.org/log4j">log4j</a>.
@@ -28,12 +38,25 @@ import org.springframework.util.Log4jConfigurer;
  */
 public class Log4JLoggingSystem extends AbstractLoggingSystem {
 
+	private static final Map<LogLevel, Level> LEVELS;
+	static {
+		Map<LogLevel, Level> levels = new HashMap<LogLevel, Level>();
+		levels.put(LogLevel.TRACE, Level.TRACE);
+		levels.put(LogLevel.DEBUG, Level.DEBUG);
+		levels.put(LogLevel.INFO, Level.INFO);
+		levels.put(LogLevel.WARN, Level.WARN);
+		levels.put(LogLevel.ERROR, Level.ERROR);
+		levels.put(LogLevel.FATAL, Level.ERROR);
+		LEVELS = Collections.unmodifiableMap(levels);
+	}
+
 	public Log4JLoggingSystem(ClassLoader classLoader) {
 		super(classLoader, "log4j.xml", "log4j.properties");
 	}
 
 	@Override
 	public void initialize(String configLocation) {
+		Assert.notNull(configLocation, "ConfigLocation must not be null");
 		try {
 			Log4jConfigurer.initLogging(configLocation);
 		}
@@ -43,4 +66,11 @@ public class Log4JLoggingSystem extends AbstractLoggingSystem {
 		}
 	}
 
+	@Override
+	public void setLogLevel(String loggerName, LogLevel level) {
+		Logger logger = (StringUtils.hasLength(loggerName) ? LogManager
+				.getLogger(loggerName) : LogManager.getRootLogger());
+		logger.setLevel(LEVELS.get(level));
+	}
+
 }

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

@@ -17,17 +17,24 @@
 package org.springframework.boot.logging.logback;
 
 import java.net.URL;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
 
 import org.slf4j.ILoggerFactory;
+import org.slf4j.Logger;
 import org.slf4j.bridge.SLF4JBridgeHandler;
 import org.slf4j.impl.StaticLoggerBinder;
 import org.springframework.boot.logging.AbstractLoggingSystem;
+import org.springframework.boot.logging.LogLevel;
 import org.springframework.boot.logging.LoggingSystem;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ResourceUtils;
+import org.springframework.util.StringUtils;
 import org.springframework.util.SystemPropertyUtils;
 
+import ch.qos.logback.classic.Level;
 import ch.qos.logback.classic.LoggerContext;
 import ch.qos.logback.classic.util.ContextInitializer;
 
@@ -39,6 +46,18 @@ import ch.qos.logback.classic.util.ContextInitializer;
  */
 public class LogbackLoggingSystem extends AbstractLoggingSystem {
 
+	private static final Map<LogLevel, Level> LEVELS;
+	static {
+		Map<LogLevel, Level> levels = new HashMap<LogLevel, Level>();
+		levels.put(LogLevel.TRACE, Level.TRACE);
+		levels.put(LogLevel.DEBUG, Level.DEBUG);
+		levels.put(LogLevel.INFO, Level.INFO);
+		levels.put(LogLevel.WARN, Level.WARN);
+		levels.put(LogLevel.ERROR, Level.ERROR);
+		levels.put(LogLevel.FATAL, Level.ERROR);
+		LEVELS = Collections.unmodifiableMap(levels);
+	}
+
 	public LogbackLoggingSystem(ClassLoader classLoader) {
 		super(classLoader, "logback.xml");
 	}
@@ -54,6 +73,7 @@ public class LogbackLoggingSystem extends AbstractLoggingSystem {
 
 	@Override
 	public void initialize(String configLocation) {
+		Assert.notNull(configLocation, "ConfigLocation must not be null");
 		String resolvedLocation = SystemPropertyUtils.resolvePlaceholders(configLocation);
 		ILoggerFactory factory = StaticLoggerBinder.getSingleton().getLoggerFactory();
 		Assert.isInstanceOf(ILoggerFactory.class, factory);
@@ -69,4 +89,13 @@ public class LogbackLoggingSystem extends AbstractLoggingSystem {
 		}
 	}
 
+	@Override
+	public void setLogLevel(String loggerName, LogLevel level) {
+		ILoggerFactory factory = StaticLoggerBinder.getSingleton().getLoggerFactory();
+		Logger logger = factory
+				.getLogger(StringUtils.isEmpty(loggerName) ? Logger.ROOT_LOGGER_NAME
+						: loggerName);
+		((ch.qos.logback.classic.Logger) logger).setLevel(LEVELS.get(level));
+	}
+
 }

spring-boot/src/main/resources/org/springframework/boot/logging/java/logging.properties

@@ -2,10 +2,11 @@ handlers = java.util.logging.FileHandler, java.util.logging.ConsoleHandler
 .level = INFO
 
 # File Logging
-java.util.logging.FileHandler.pattern = %t/service.log
+java.util.logging.FileHandler.pattern = %t/spring.log
 java.util.logging.FileHandler.formatter = org.springframework.boot.logging.java.SimpleFormatter
-java.util.logging.FileHandler.level = INFO
+java.util.logging.FileHandler.level = ALL
 java.util.logging.FileHandler.limit = 10485760
 java.util.logging.FileHandler.count = 10
 
 java.util.logging.ConsoleHandler.formatter = org.springframework.boot.logging.java.SimpleFormatter
+java.util.logging.ConsoleHandler.level = ALL

spring-boot/src/main/resources/org/springframework/boot/logging/log4j/log4j.properties

 log4j.rootCategory=INFO, CONSOLE, FILE
 
 PID=????
-catalina.base=/tmp
-LOG_PATH=${catalina.base}/logs
-LOG_FILE=${LOG_PATH}/service.log
+LOG_PATH=/tmp
+LOG_FILE=${LOG_PATH}/spring.log
 LOG_PATTERN=[%d{yyyy-MM-dd HH:mm:ss.SSS}] service%X{context} - ${PID} %5p [%t] --- %c{1}: %m%n
 
 # CONSOLE is set to be a ConsoleAppender using a PatternLayout.

spring-boot/src/test/java/org/springframework/boot/logging/java/JavaLoggerSystemTests.java

@@ -19,15 +19,17 @@ package org.springframework.boot.logging.java;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.PrintStream;
-import java.util.logging.LogManager;
 
 import org.apache.commons.logging.impl.Jdk14Logger;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
-import org.springframework.boot.logging.java.JavaLoggingSystem;
+import org.springframework.boot.logging.LogLevel;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.StringUtils;
 
+import static org.hamcrest.Matchers.equalTo;
+import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 
 /**
@@ -48,8 +50,6 @@ public class JavaLoggerSystemTests {
 
 	@Before
 	public void init() throws SecurityException, IOException {
-		LogManager.getLogManager().readConfiguration(
-				getClass().getResourceAsStream("/logging.properties"));
 		this.logger = new Jdk14Logger(getClass().getName());
 		this.savedOutput = System.err;
 		this.output = new ByteArrayOutputStream();
@@ -71,6 +71,7 @@ public class JavaLoggerSystemTests {
 
 	@Test
 	public void testCustomFormatter() throws Exception {
+		this.loggingSystem.initialize();
 		this.logger.info("Hello world");
 		String output = getOutput().trim();
 		assertTrue("Wrong output:\n" + output, output.contains("Hello world"));
@@ -108,4 +109,14 @@ public class JavaLoggerSystemTests {
 		this.loggingSystem.initialize(null);
 	}
 
+	@Test
+	public void setLevel() throws Exception {
+		this.loggingSystem.initialize();
+		this.logger.debug("Hello");
+		this.loggingSystem.setLogLevel("org.springframework.boot", LogLevel.DEBUG);
+		this.logger.debug("Hello");
+		assertThat(StringUtils.countOccurrencesOf(this.output.toString(), "Hello"),
+				equalTo(1));
+	}
+
 }

spring-boot/src/test/java/org/springframework/boot/logging/log4j/Log4JLoggingSystemTests.java

+/*
+ * Copyright 2012-2013 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.boot.logging.log4j;
+
+import org.apache.commons.logging.impl.Log4JLogger;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.springframework.boot.OutputCapture;
+import org.springframework.boot.logging.LogLevel;
+import org.springframework.util.StringUtils;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Tests for {@link Log4JLoggingSystem}.
+ * 
+ * @author Phillip Webb
+ */
+public class Log4JLoggingSystemTests {
+
+	@Rule
+	public OutputCapture output = new OutputCapture();
+
+	private Log4JLoggingSystem loggingSystem = new Log4JLoggingSystem(getClass()
+			.getClassLoader());
+
+	private Log4JLogger logger;
+
+	@Before
+	public void setup() {
+		this.logger = new Log4JLogger(getClass().getName());
+	}
+
+	@After
+	public void clear() {
+		System.clearProperty("LOG_FILE");
+		System.clearProperty("LOG_PATH");
+		System.clearProperty("PID");
+	}
+
+	@Test
+	public void testNonDefaultConfigLocation() throws Exception {
+		this.loggingSystem.initialize("classpath:log4j-nondefault.properties");
+		this.logger.info("Hello world");
+		String output = this.output.toString().trim();
+		assertTrue("Wrong output:\n" + output, output.contains("Hello world"));
+		assertTrue("Wrong output:\n" + output, output.contains("/tmp/spring.log"));
+	}
+
+	@Test(expected = IllegalStateException.class)
+	public void testNonexistentConfigLocation() throws Exception {
+		this.loggingSystem.initialize("classpath:log4j-nonexistent.xml");
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void testNullConfigLocation() throws Exception {
+		this.loggingSystem.initialize(null);
+	}
+
+	@Test
+	public void setLevel() throws Exception {
+		this.loggingSystem.initialize();
+		this.logger.debug("Hello");
+		this.loggingSystem.setLogLevel("org.springframework.boot", LogLevel.DEBUG);
+		this.logger.debug("Hello");
+		assertThat(StringUtils.countOccurrencesOf(this.output.toString(), "Hello"),
+				equalTo(1));
+	}
+
+}

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

@@ -17,12 +17,17 @@
 package org.springframework.boot.logging.logback;
 
 import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
+import org.apache.commons.logging.impl.SLF4JLogFactory;
 import org.junit.After;
+import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.springframework.boot.OutputCapture;
+import org.springframework.boot.logging.LogLevel;
+import org.springframework.util.StringUtils;
 
+import static org.hamcrest.Matchers.equalTo;
+import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 
 /**
@@ -33,11 +38,18 @@ import static org.junit.Assert.assertTrue;
 public class LogbackLoggingSystemTests {
 
 	@Rule
-	public OutputCapture outputCapture = new OutputCapture();
+	public OutputCapture output = new OutputCapture();
 
 	private LogbackLoggingSystem loggingSystem = new LogbackLoggingSystem(getClass()
 			.getClassLoader());
 
+	private Log logger;
+
+	@Before
+	public void setup() {
+		this.logger = new SLF4JLogFactory().getInstance(getClass().getName());
+	}
+
 	@After
 	public void clear() {
 		System.clearProperty("LOG_FILE");
@@ -46,13 +58,12 @@ public class LogbackLoggingSystemTests {
 	}
 
 	@Test
-	public void testDefaultConfigLocation() throws Exception {
+	public void testNonDefaultConfigLocation() throws Exception {
 		this.loggingSystem.initialize("classpath:logback-nondefault.xml");
-		Log logger = LogFactory.getLog(LogbackLoggingSystemTests.class);
-		logger.info("Hello world");
-		String output = this.outputCapture.toString().trim();
+		this.logger.info("Hello world");
+		String output = this.output.toString().trim();
 		assertTrue("Wrong output:\n" + output, output.contains("Hello world"));
-		assertTrue("Wrong output:\n" + output, output.startsWith("/tmp/spring.log"));
+		assertTrue("Wrong output:\n" + output, output.contains("/tmp/spring.log"));
 	}
 
 	@Test(expected = IllegalStateException.class)
@@ -65,4 +76,14 @@ public class LogbackLoggingSystemTests {
 		this.loggingSystem.initialize(null);
 	}
 
+	@Test
+	public void setLevel() throws Exception {
+		this.loggingSystem.initialize();
+		this.logger.debug("Hello");
+		this.loggingSystem.setLogLevel("org.springframework.boot", LogLevel.DEBUG);
+		this.logger.debug("Hello");
+		assertThat(StringUtils.countOccurrencesOf(this.output.toString(), "Hello"),
+				equalTo(1));
+	}
+
 }

spring-boot/src/test/resources/log4j-nondefault.properties

+log4j.reset=true
+log4j.rootCategory=INFO, CONSOLE
+
+PID=????
+LOG_PATH=/tmp
+LOG_FILE=${LOG_PATH}/spring.log
+LOG_PATTERN=${LOG_FILE} %d{yyyy-MM-dd HH:mm:ss.SSS}] service%X{context} - ${PID} %5p [%t] --- %c{1}: %m%n
+
+# CONSOLE is set to be a ConsoleAppender using a PatternLayout.
+log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
+log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
+log4j.appender.CONSOLE.layout.ConversionPattern=${LOG_PATTERN}

spring-boot/src/test/resources/logging.properties

-handlers= java.util.logging.ConsoleHandler
-.level= INFO
-java.util.logging.ConsoleHandler.level = INFO
-java.util.logging.ConsoleHandler.formatter = org.springframework.boot.logging.java.SimpleFormatter