AbstractLogService: extract class DefaultLogger

This provides an implementation of Logger that can be used
independently from AbstractLogService. It will be useful
for the implementation of sub loggers.

Author: maarzt

src/main/java/org/scijava/log/AbstractLogService.java

@@ -33,10 +33,8 @@
 package org.scijava.log;
 
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 import java.util.Properties;
-import java.util.concurrent.CopyOnWriteArrayList;
 
 import org.scijava.service.AbstractService;
 
@@ -45,6 +43,7 @@
  *
  * @author Johannes Schindelin
  * @author Curtis Rueden
+ * @author Matthias Arzt
  */
 @IgnoreAsCallingClass
 public abstract class AbstractLogService extends AbstractService implements
@@ -55,7 +54,7 @@ public abstract class AbstractLogService extends AbstractService implements
 
 	private final Map<String, Integer> classAndPackageLevels;
 
-	private final List<LogListener> listeners = new CopyOnWriteArrayList<>();
+	private final Logger rootLogger;
 
 	// -- constructor --
 
@@ -64,6 +63,7 @@ public AbstractLogService() {
 	}
 
 	public AbstractLogService(final Properties properties) {
+		rootLogger = new RootLogger();
 		// provide this constructor to enable unit tests
 		final int level = LogLevel.value(properties.getProperty(
 			LogService.LOG_LEVEL_PROPERTY));
@@ -74,10 +74,7 @@ public AbstractLogService(final Properties properties) {
 
 	// -- AbstractLogService methods --
 
-	protected void notifyListeners(LogMessage message) {
-		for (LogListener listener : listeners)
-			listener.messageLogged(message);
-	}
+	abstract void notifyListeners(LogMessage message);
 
 	// -- Logger methods --
 
@@ -100,17 +97,17 @@ public void setLevel(final String classOrPackageName, final int level) {
 
 	@Override
 	public void alwaysLog(final int level, final Object msg, final Throwable t) {
-		notifyListeners(new LogMessage(level, msg, t));
+		rootLogger.alwaysLog(level, msg, t);
 	}
 
 	@Override
 	public void addListener(final LogListener listener) {
-		listeners.add(listener);
+		rootLogger.addListener(listener);
 	}
 
 	@Override
 	public void removeListener(final LogListener listener) {
-		listeners.remove(listener);
+		rootLogger.removeListener(listener);
 	}
 
 	// -- Deprecated --
@@ -155,4 +152,24 @@ private Map<String, Integer> setupMapFromProperties(Properties properties,
 			}
 		return map;
 	}
+
+	// -- Helper classes --
+
+	@IgnoreAsCallingClass
+	private class RootLogger extends DefaultLogger {
+
+		public RootLogger() {
+			super(LogLevel.NONE);
+		}
+
+		@Override
+		public int getLevel() {
+			return AbstractLogService.this.getLevel();
+		}
+
+		@Override
+		protected void messageLogged(LogMessage message) {
+			AbstractLogService.this.notifyListeners(message);
+		}
+	}
 }

src/main/java/org/scijava/log/DefaultLogger.java

@@ -0,0 +1,82 @@
+/*
+ * #%L
+ * SciJava Common shared library for SciJava software.
+ * %%
+ * Copyright (C) 2009 - 2017 Board of Regents of the University of
+ * Wisconsin-Madison, Broad Institute of MIT and Harvard, and Max Planck
+ * Institute of Molecular Cell Biology and Genetics.
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * #L%
+ */
+
+package org.scijava.log;
+
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+/**
+ * Default implementation of {@link Logger}.
+ *
+ * @author Matthias Arzt
+ */
+@IgnoreAsCallingClass
+public class DefaultLogger implements Logger {
+
+	private final int level;
+
+	private final List<LogListener> listeners = new CopyOnWriteArrayList<>();
+
+	public DefaultLogger(final int level)
+	{
+		this.level = level;
+	}
+
+	// -- DefaultLogger methods --
+
+	protected void messageLogged(final LogMessage message) {
+		for (LogListener listener : listeners)
+			listener.messageLogged(message);
+	}
+
+	// -- Logger methods --
+
+	@Override
+	public int getLevel() {
+		return level;
+	}
+
+	@Override
+	public void alwaysLog(final int level, final Object msg, final Throwable t) {
+		messageLogged(new LogMessage(level, msg, t));
+	}
+
+	@Override
+	public void addListener(final LogListener listener) {
+		listeners.add(listener);
+	}
+
+	@Override
+	public void removeListener(final LogListener listener) {
+		listeners.remove(listener);
+	}
+}

src/main/java/org/scijava/log/StderrLogService.java

@@ -54,7 +54,6 @@ public class StderrLogService extends AbstractLogService {
 
 	@Override
 	public void notifyListeners(final LogMessage message) {
-		super.notifyListeners(message);
 		final PrintStream out = (message.level() <= LogLevel.WARN) ? System.err
 			: System.out;
 		out.print(message);

src/test/java/org/scijava/log/DefaultLoggerTest.java

@@ -0,0 +1,65 @@
+/*
+ * #%L
+ * SciJava Common shared library for SciJava software.
+ * %%
+ * Copyright (C) 2009 - 2017 Board of Regents of the University of
+ * Wisconsin-Madison, Broad Institute of MIT and Harvard, and Max Planck
+ * Institute of Molecular Cell Biology and Genetics.
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * #L%
+ */
+
+package org.scijava.log;
+
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Tests {@link DefaultLogger}
+ *
+ * @author Matthias Arzt
+ */
+public class DefaultLoggerTest {
+
+	private Logger logger;
+	private TestLogListener listener;
+
+	@Before
+	public void setup() {
+		logger = new DefaultLogger(LogLevel.INFO);
+		listener = new TestLogListener();
+		logger.addListener(listener);
+	}
+
+	@Test
+	public void test() {
+		listener.clear();
+
+		logger.error("Hello World!");
+
+		assertTrue(listener.hasLogged(m -> m.text().equals("Hello World!")));
+		assertTrue(listener.hasLogged(m -> m.level() == LogLevel.ERROR));
+	}
+}

src/test/java/org/scijava/log/LogServiceTest.java

@@ -219,9 +219,9 @@ public Throwable exception() {
 		}
 
 		@Override
-		public void alwaysLog(int level, Object msg, Throwable t) {
-			this.message = LogLevel.prefix(level) + msg;
-			this.exception = t;
+		void notifyListeners(LogMessage message) {
+			this.message = message.toString();
+			this.exception = message.throwable();
 		}
 	}
 }