diff --git a/src/main/java/mpo/dayon/common/log/Log.java b/src/main/java/mpo/dayon/common/log/Log.java
index d64633bc..1d59a7b6 100644
--- a/src/main/java/mpo/dayon/common/log/Log.java
+++ b/src/main/java/mpo/dayon/common/log/Log.java
@@ -18,26 +18,24 @@
 public final class Log {
     private static final boolean DEBUG = System.getProperty("dayon.debug") != null;
 
-    private static LogAppender out;
+    private static final LogAppender out;
 
     private Log() {
     }
 
     static {
-        final String mode = System.getProperty("dayon.log", "console");
-        out = new ConsoleAppender();
-
-        if ("file".equals(mode)) {
-            try {
-                final File logFile = getOrCreateLogFile();
-                // console ...
-                info("Log logFile : " + logFile.getAbsolutePath());
-                // logFile ...§
-                out = new FileAppender(logFile.getAbsolutePath());
-            } catch (IOException ex) {
-                // console ...
-                warn("Log file setup error (fallback to console)!", ex);
-            }
+        String mode = System.getProperty("dayon.log", "console");
+        out = mode.equals("file") ? createFileAppender() : new ConsoleAppender();
+    }
+
+    private static LogAppender createFileAppender() {
+        try {
+            File logFile = getOrCreateLogFile();
+            info("Log logFile : " + logFile.getAbsolutePath());
+            return new FileAppender(logFile.getAbsolutePath());
+        } catch (IOException ex) {
+            warn("Log file setup error (fallback to console)!", ex);
+            return new ConsoleAppender();
         }
     }
 
diff --git a/src/main/java/mpo/dayon/common/log/file/FileAppender.java b/src/main/java/mpo/dayon/common/log/file/FileAppender.java
index 5d7e26a9..32855633 100644
--- a/src/main/java/mpo/dayon/common/log/file/FileAppender.java
+++ b/src/main/java/mpo/dayon/common/log/file/FileAppender.java
@@ -38,24 +38,21 @@ public FileAppender(String filename) throws FileNotFoundException {
 	@Override
     public synchronized void append(LogLevel level, String message, Throwable error) {
 		try {
-			final String info = format(level, message);
-
-			writer.println(info);
-			writer.flush();
-
-			count += info.length();
+			StringBuilder builder = new StringBuilder();
+			builder.append(format(level, message)).append(System.lineSeparator());
+			count += message.length();
 
 			if (error != null) {
-				final String stack = getStackTrace(error);
-				writer.println(stack);
-				writer.flush();
-
-				count += stack.length();
+				builder.append(getStackTrace(error)).append(System.lineSeparator());
+				count += getStackTrace(error).length();
 			}
 
 			if (count >= MAX_FILE_SIZE && count >= nextRolloverCount) {
 				rollOver();
 			}
+
+			writer.write(builder.toString());
+			writer.flush();
 		} catch (RuntimeException ex) {
 			fallback.append(level, message, error);
 			fallback.append(LogLevel.WARN, "[FileAppender] error", ex);