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Thread: image url cannot be converted to bytes

  1. #1
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    Default image url cannot be converted to bytes

    I want to get an image from a url, convert it into bytes and encrypt it using AES. However, when I try to compile the code for my Server, I get this error:
        Server1.java:77: error: cannot find symbol
                                    plainpic = Base64.getUrlEncoder().encodeToString(myimage.getBytes());
     
          symbol:   method getBytes()
          location: variable myimage of type URL
    Why is this so? Below is the code for my server which generates an AES key and tries to convert a image url to bytes.

    Server1.java
        public class Server1 { 
        public static void main (String [] args ) throws InvalidKeyException, IOException, Exception { 
    		ServerSocket serverSocket = new ServerSocket(15123);
    		Socket socket = null;
    		//start of AES
    		//Generate AES Key
    		int sizeofkey = 128;
    		KeyGenerator kg = KeyGenerator.getInstance("AES");
    		//initialize with sizeofkey
    		kg.init(sizeofkey);
    		Key mykey = kg.generateKey();
    		System.out.println("Key Generated");
    		//create cipher object & initialize with generated key
    		Cipher cipher = Cipher.getInstance("AES/ECB/PCKS5PADDING");
    		cipher.init(Cipher.ENCRYPT_MODE, mykey);
     
    		while(true)	{
    			socket = serverSocket.accept();
    			System.out.println("Accepted connection : " + socket.getRemoteSocketAddress().toString() + " <-> /127.0.0.1:15123" );
    			DataOutputStream dos = new DataOutputStream(socket.getOutputStream());
     
    			// get the image from a webcam
    			URL myimage = new URL("http://183.76.13.58:80/SnapshotJPEG?Resolution=640x480");
     
     
    			DataInputStream in = null;
     
    			String plainpic = null;
    			try	{
    				in = new DataInputStream(myimage.openStream()); 
     
                    //Error
    				plainpic = Base64.getUrlEncoder().encodeToString(myimage.getBytes());
    			} 	       
    			catch (Exception ee)	{
    				System.out.println("Check internet connection please");
    				socket.close(); 
    				return;
    			}          
    			DateFormat dateFormat = new SimpleDateFormat("yy/MM/dd HH:mm:ss");
    			Date date = new Date();
    			System.out.println("Sending image " + dateFormat.format(date));
     
    			try	{
    				while (true) {
    					dos.writeByte(in.readByte()); 
    				} 
    			}
    			catch (EOFException ee)	{ 
    				System.out.println("-------------- Done ----------"); 
    				in.close();
    			}
     
    			dos.flush();
    			dos.close();
    			socket.close();
        }
     
          } 
        }
    Last edited by wei123; February 13th, 2018 at 08:10 AM.

  2. #2
    Super Moderator Norm's Avatar
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    Default Re: image url cannot be converted to bytes

    Server1.java:77: error: cannot find symbol
    plainpic = Base64.getUrlEncoder().encodeToString(myimage.getB ytes());

    symbol: method getBytes()
    location: variable myimage of type URL
    The compiler can not find a method named getBytes() for the class URL.
    Try reading the image file into a byte array that can be passed to the encode method.
    If you don't understand my answer, don't ignore it, ask a question.

  3. #3
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    Default Re: image url cannot be converted to bytes

    Is this fine?
    			is = myimage.openStream ();
    			byte[] byteChunk = new byte[4096]; 
    			int n;
     
    			while ( (n = is.read(byteChunk)) > 0 ) {
    			baos.write(byteChunk, 0, n);
    				}
    				plainpic=Base64.getUrlEncoder().encodeToString(baos.toByteArray());

  4. #4
    Super Moderator Norm's Avatar
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    Default Re: image url cannot be converted to bytes

    Did you try it?
    What happened?
    If you don't understand my answer, don't ignore it, ask a question.

  5. #5
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    Default Re: image url cannot be converted to bytes

    Yup, it worked! I printed the string and the output was what I wanted.

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