android image draws of five canvases save the image in the specified format and size

Edit the image (shrink, doodle, etc.) and save it to the specified format and size.
First paste the code:

 
Bitmap bmp = Bitmap.createBitmap(480, 800, Config.ARGB_8888); 
Canvas canvas = new Canvas(bmp); 
canvas.drawBitmap(this.bmp, matrix, paint); 
canvas.save(Canvas.ALL_SAVE_FLAG); 
canvas.restore(); 

File file = new File("/sdcard/akai/"); 
if(!file.exists()) 
file.mkdirs(); 
try { 
FileOutputStream fos = new FileOutputStream(file.getPath() + "/2.png"); 
bmp.compress(Bitmap.CompressFormat.PNG, 100, fos); 
fos.close(); 
System.out.println("saveBmp is here"); 
} catch (Exception e) { 
e.printStackTrace(); 
} 

Explanation:
1. First create an Bitmap image and specify the size;
2. Create a new canvas Canvas on the image, then draw it on the canvas and save it;
3, need to save the directory File, note that if the directory such as "/sdcard/akai/" does not exist, to create (file.mkdirs ()), otherwise FileOutputStream will report an error No found;
4. Permissions need to be added: < uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/ >