--- old/src/java.desktop/share/classes/javax/sound/sampled/AudioFileFormat.java	2014-08-21 20:50:53.000000000 +0800
+++ new/src/java.desktop/share/classes/javax/sound/sampled/AudioFileFormat.java	2014-08-21 20:50:53.000000000 +0800
@@ -272,26 +272,25 @@
     @Override
     public String toString() {
 
-        StringBuffer buf = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
 
         //$$fb2002-11-01: fix for 4672864: AudioFileFormat.toString() throws unexpected NullPointerException
         if (type != null) {
-            buf.append(type.toString() + " (." + type.getExtension() + ") file");
+            sb.append(type.toString()).append(" (.").append(type.getExtension()).append(") file");
         } else {
-            buf.append("unknown file format");
+            sb.append("unknown file format");
         }
 
         if (byteLength != AudioSystem.NOT_SPECIFIED) {
-            buf.append(", byte length: " + byteLength);
+            sb.append(", byte length: ").append(byteLength);
         }
 
-        buf.append(", data format: " + format);
+        sb.append(", data format: ").append(format);
 
         if (frameLength != AudioSystem.NOT_SPECIFIED) {
-            buf.append(", frame length: " + frameLength);
+            sb.append(", frame length: ").append(frameLength);
         }
-
-        return new String(buf);
+        return sb.toString();
     }
 
     /**