Optional SLF4J support without adding compile time dependency

commons/pom.xml

@@ -29,6 +29,12 @@
             <version>5.14.1</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+        	<groupId>org.slf4j</groupId>
+        	<artifactId>slf4j-api</artifactId>
+        	<version>1.7.2</version>
+        	<scope>provided</scope>
+        </dependency>
     </dependencies>
 
     <build>

commons/src/main/java/com/orientechnologies/common/log/OJulLogger.java

@@ -0,0 +1,21 @@
+package com.orientechnologies.common.log;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class OJulLogger implements OLogger {
+
+	@Override
+	public void log(String name, Level iLevel, String iMessage, Throwable iException,
+			Object... iAdditionalArgs) {
+		Logger log = Logger.getLogger(name);
+		if (log.isLoggable(iLevel)) {
+			final String msg = String.format(iMessage, iAdditionalArgs);
+			if (iException != null)
+				log.log(iLevel, msg, iException);
+			else
+				log.log(iLevel, msg);
+		}
+	}
+
+}

commons/src/main/java/com/orientechnologies/common/log/OLogManager.java

@@ -20,8 +20,16 @@ public class OLogManager {
   private static final String      DEFAULT_LOG  = "com.orientechnologies";
 
   private static final OLogManager instance     = new OLogManager();
+  private OLogger                  loggerImpl;
 
   protected OLogManager() {
+	  try {
+		  Class.forName("org.slf4j.Logger");
+		  loggerImpl = new OSlf4JLogger();
+	  }
+	  catch(ClassNotFoundException e) {
+		  loggerImpl = new OJulLogger();
+	  }
   }
 
   public void setConsoleLevel(final String iLevel) {
@@ -35,14 +43,7 @@ public void setFileLevel(final String iLevel) {
   public void log(final Object iRequester, final Level iLevel, String iMessage, final Throwable iException,
       final Object... iAdditionalArgs) {
     if (iMessage != null) {
-      final Logger log = iRequester != null ? Logger.getLogger(iRequester.getClass().getName()) : Logger.getLogger(DEFAULT_LOG);
-      if (log.isLoggable(iLevel)) {
-        final String msg = String.format(iMessage, iAdditionalArgs);
-        if (iException != null)
-          log.log(iLevel, msg, iException);
-        else
-          log.log(iLevel, msg);
-      }
+    	loggerImpl.log(iRequester != null ? iRequester.getClass().getName() : DEFAULT_LOG, iLevel, iMessage, iException, iAdditionalArgs);
     }
   }
 

commons/src/main/java/com/orientechnologies/common/log/OLogger.java

@@ -0,0 +1,11 @@
+package com.orientechnologies.common.log;
+
+import java.util.logging.Level;
+
+public interface OLogger {
+
+
+	void log(final String name, final Level iLevel, String iMessage,
+			final Throwable iException, final Object... iAdditionalArgs);
+
+}

commons/src/main/java/com/orientechnologies/common/log/OSlf4JLogger.java

@@ -0,0 +1,29 @@
+package com.orientechnologies.common.log;
+
+import java.util.logging.Level;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class OSlf4JLogger implements OLogger {
+
+	@Override
+	public void log(String name, Level iLevel, String iMessage,
+			Throwable iException, Object... iAdditionalArgs) {
+		Logger logger = LoggerFactory.getLogger(name);
+
+		if (canLog(logger, iLevel)) {
+			String msg = String.format(iMessage, iAdditionalArgs);
+			logger.info(msg, iException);
+
+		}
+
+	}
+
+	private boolean canLog(Logger logger, Level iLevel) {
+		return (Level.INFO == iLevel && logger.isInfoEnabled()
+				|| Level.WARNING == iLevel && logger.isWarnEnabled()
+				|| Level.SEVERE == iLevel && logger.isErrorEnabled() 
+				|| (Level.FINE == iLevel || Level.FINER == iLevel || Level.FINEST == iLevel) && logger.isDebugEnabled());
+	}
+}