diff --git a/src/fr/devinsy/sikevadb/filetree/FileTreeSikevaDB.java b/src/fr/devinsy/sikevadb/filetree/FileTreeSikevaDB.java
index e17e3ef..2b2086f 100644
--- a/src/fr/devinsy/sikevadb/filetree/FileTreeSikevaDB.java
+++ b/src/fr/devinsy/sikevadb/filetree/FileTreeSikevaDB.java
@@ -152,7 +152,7 @@ public class FileTreeSikevaDB implements SikevaDB
 			}
 			catch (IOException exception)
 			{
-				this.logger.error("Error clearing database", exception);
+				logger.error("Error clearing database", exception);
 				throw new SikevaDBException("Error clearing database", exception);
 			}
 		}
@@ -1368,7 +1368,7 @@ public class FileTreeSikevaDB implements SikevaDB
 	@Override
 	public void renameKey(final String oldKey, final String newKey) throws SikevaDBException
 	{
-		this.logger.debug("renameKey starting... [{}][{}]", oldKey, newKey);
+		logger.debug("renameKey starting... [{}][{}]", oldKey, newKey);
 
 		if (isClosed())
 		{
@@ -1404,7 +1404,7 @@ public class FileTreeSikevaDB implements SikevaDB
 			}
 		}
 
-		this.logger.debug("renameKey done.");
+		logger.debug("renameKey done.");
 	}
 
 	/* (non-Javadoc)
@@ -1429,7 +1429,7 @@ public class FileTreeSikevaDB implements SikevaDB
 	@Override
 	public void renameSubkey(final String key, final String oldSubkey, final String newSubkey) throws SikevaDBException
 	{
-		this.logger.debug("renameSybKey starting... [{}][{}][{}]", oldSubkey, newSubkey);
+		logger.debug("renameSybKey starting... [{}][{}][{}]", oldSubkey, newSubkey);
 
 		if (isClosed())
 		{
@@ -1470,7 +1470,7 @@ public class FileTreeSikevaDB implements SikevaDB
 			}
 		}
 
-		this.logger.debug("renameSubKey done.");
+		logger.debug("renameSubKey done.");
 	}
 
 	/* (non-Javadoc)
@@ -1479,7 +1479,7 @@ public class FileTreeSikevaDB implements SikevaDB
 	@Override
 	public void replaceInValue(final String key, final String... tokens) throws SikevaDBException
 	{
-		this.logger.info("replaceInValue starting... [{}]", key);
+		logger.info("replaceInValue starting... [{}]", key);
 
 		if (isClosed())
 		{
@@ -1497,7 +1497,7 @@ public class FileTreeSikevaDB implements SikevaDB
 			put(key, value);
 		}
 
-		this.logger.info("replaceInValue done.");
+		logger.info("replaceInValue done.");
 	}
 
 	/* (non-Javadoc)
@@ -1506,7 +1506,7 @@ public class FileTreeSikevaDB implements SikevaDB
 	@Override
 	public void replaceInValues(final String key, final String... tokens) throws SikevaDBException
 	{
-		this.logger.info("replaceInValues starting... [{}]", key);
+		logger.info("replaceInValues starting... [{}]", key);
 
 		if (isClosed())
 		{
@@ -1519,7 +1519,7 @@ public class FileTreeSikevaDB implements SikevaDB
 			long count = 0;
 			for (Element element : elements)
 			{
-				this.logger.info(element.getKey() + " (" + element.getSubkey() + ") " + count + "/" + elements.size());
+				logger.info(element.getKey() + " (" + element.getSubkey() + ") " + count + "/" + elements.size());
 
 				if (element.getSubkey() != null)
 				{
@@ -1541,7 +1541,7 @@ public class FileTreeSikevaDB implements SikevaDB
 			}
 		}
 
-		this.logger.info("replaceInValues done.");
+		logger.info("replaceInValues done.");
 	}
 
 	/**