--- a/src/main/java/jp/ac/uryukyu/ie/e165759/FileWrite.java	Thu Nov 16 18:05:16 2017 +0900
+++ b/src/main/java/jp/ac/uryukyu/ie/e165759/FileWrite.java	Fri Nov 17 18:06:06 2017 +0900
@@ -7,6 +7,7 @@
     private long writeSize = 4096;
     private String filename = "testData.txt";
     private int writeData = '0';
+    private int bufferSize=0;
 
     public static void main(String args[]) throws IOException {
         FileWrite filewrite = new FileWrite();
@@ -22,6 +23,13 @@
         for(int i=0;i < args.length;i++){
             switch (args[i]) {
                 case "-b" : isBuffering = true; break;
+                case "-bs" : isBuffering = true;
+                    if(i+1 <= args.length) {
+                        bufferSize = Integer.parseInt(args[i+1]);
+                        i++;
+                    }
+                    break;
+
                 case "-u" : isBuffering = false; break;
                 case "-s" :
                     if (i+1<=args.length){
@@ -29,6 +37,9 @@
                         i++;
                     }
                     break;
+                case "-h" :
+                    System.out.println(args);
+                    break;
             }
         }
     }
@@ -41,7 +52,11 @@
 
         OutputStream os = new FileOutputStream(filename);
         if(isBuffering) {
-            os = new BufferedOutputStream(os);
+            if(bufferSize>0){
+                os = new BufferedOutputStream(os,bufferSize);
+            }else {
+                os = new BufferedOutputStream(os);
+            }
         }
         while(written < size){
             os.write(data);