Executing scanimage command from Java

Question

I am trying to run scanimage command from java. Command is successfully executed but i can't read image that is returned from command. I want to read image from terminal and convert it to base64 string via Java. My code:

public String getimagefromscanner(String device)
{
 try {
 Process p = Runtime.getRuntime().exec("scanimage --resolution=300 -l 0 -t 0 -y 297 -x 210 --device-name " + device);
 BufferedInputStream input = new BufferedInputStream(p.getInputStream());
 byte[] file = new byte[input.available()];
 input.read(file);
 String result = new String(Base64.getDecoder().decode(file));
 p.waitFor();
 p.destroy();
 return result;
 } catch (IOException e) {
 return e.getLocalizedMessage();
 } catch (InterruptedException e) {
 return e.getLocalizedMessage();
 }
}

• Yosef Weiner: Possible duplicate of read the output from java exec
• Burak: Yes i can read line as string but i don't know how to convert to base64. I dont know which data type returns. It returns 304DNpï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿ ...
• Burak: It doesnt work.

Answer 1

Finnaly I solved my problem. Maybe someone else needs answer. Here my solution

public String getimage(String device)
{
 try{
 Process p = Runtime.getRuntime().exec("scanimage --resolution=300 -l 0 -t 0 -y 297 -x 210 --format png --device-name " + device);
 InputStream in = p.getInputStream();
 ByteArrayOutputStream out = new ByteArrayOutputStream();
 byte[] buffer = new byte[8*1024];
 int bytesRead, totalbytes = 0;
 while ((bytesRead = in.read(buffer)) != -1) {
 out.write(buffer, 0, bytesRead);
 }
 String result = Base64.getEncoder().encodeToString(out.toByteArray());
 out.close();
 p.waitFor();
 p.destroy();
 in.close();
 return result;
 } catch (IOException e) {
 return e.getLocalizedMessage();
 } catch (InterruptedException e) {
 return e.getLocalizedMessage();
 }
}