I have trouble to sending data from Android Client to NodeJS Server.
I use Socket.IO-client java library in my client.
But, there is not much information for me.
How can i sending binary data from android client to nodejs server?
You can use Base64 to encode the image:
public void sendImage(String path)
{
JSONObject sendData = new JSONObject();
try{
sendData.put("image", encodeImage(path));
socket.emit("message",sendData);
}catch(JSONException e){
}
}
private String encodeImage(String path)
{
File imagefile = new File(path);
FileInputStream fis = null;
try{
fis = new FileInputStream(imagefile);
}catch(FileNotFoundException e){
e.printStackTrace();
}
Bitmap bm = BitmapFactory.decodeStream(fis);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.JPEG,100,baos);
byte[] b = baos.toByteArray();
String encImage = Base64.encodeToString(b, Base64.DEFAULT);
//Base64.de
return encImage;
}
So basically you are sending a string to node.js
If you want to receive the image just decode in Base64:
private Bitmap decodeImage(String data)
{
byte[] b = Base64.decode(data,Base64.DEFAULT);
Bitmap bmp = BitmapFactory.decodeByteArray(b,0,b.length);
return bmp;
}
Related
Someone is providing a S3 Presigned URL so that I can upload my images to that link. All my images are on the website. Is there a way in JAVA to copy the image URL to the new URL provided ?
I am trying to do this. Seems like an overkill
try {
// Get Image from URL
URL urlGet = new URL("http://something.com/something.png");
BufferedImage image = ImageIO.read(urlGet);
//for png
ImageIO.write(image, "png",new File("/something.png"));
// for jpg
//ImageIO.write(image, "jpg",new File("/something.jpg"));
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
ImageIO.write(image, "png", outputStream);
outputStream.flush();
byte[] imageInBytes = outputStream.toByteArray();
outputStream.close();
URL url = new URL(putUrl);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestMethod(HttpMethod.PUT);
connection.setRequestProperty(HttpHeaders.CONTENT_TYPE, PNG_MIME_TYPE);
OutputStream stream = connection.getOutputStream();
try {
stream.write(imageInBytes);
} finally {
stream.close();
connection.disconnect();
}
switch (connection.getResponseCode()) {
case HttpURLConnection.HTTP_OK:
return "";
default:
break;
}
} catch (Exception e) {
log.error("Exception occured", e);
throw e;
}
There would be no point converting to BufferedImage and back for the copy when you can preserve the byte stream of the original files. The first part can be replaced with simple call to extract the bytes off your website:
byte[] imageInBytes = read(urlGet);
Where read() is:
private static byte[] read(URL url) throws IOException {
ByteArrayOutputStream out = new ByteArrayOutputStream(16*1024);
try (var in = url.openStream()) {
in.transferTo(out);
}
return out.toByteArray();
}
If you use JDK11 onwards you could try the HttpClient class for the GET and POSTs, for example this does same as above if passing it urlGet.toURI():
private static byte[] read(URI uri) throws IOException, InterruptedException
{
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder().uri(uri).build();
var resp = client.send(request, BodyHandlers.ofByteArray());
return resp.body();
}
I'm not able to convert pdf file to base64 string but file uploaded successfully when I open pdf file it showing 0kb file size. This same code works for an image but when I try to use to convert for pdf file it is not working. in my code I have created a method called 'NewBase64' in that I'm converting pdf file to base64 can any tell me where I'm gone wrong plz help me.
private String KEY_IMAGE = "image";
private String KEY_NAME = "name";
private int PICK_IMAGE_REQUEST = 1;
VolleyAppController volleyAppController;
mydb db;
public static String url = "http://xxx.xxx.x.x:xx/Android_Service.asmx/UploadPDFFile";
int SELECT_MAGAZINE_FILE = 1;
private File myFile;
String encodeFileToBase64Binary = "";
private String NewBase64(String Path) {
String encoded = "";
try {
File file = new File(Path);
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(bos);
oos = new ObjectOutputStream(bos);
oos.writeObject(file);
bos.close();
oos.close();
byte[] bytearray = bos.toByteArray();
encoded = Base64.encodeToString(bytearray, Base64.DEFAULT);
} catch (Exception ex) {
}
return encoded;
}
private void uploadImage() {
#RequiresApi(api = Build.VERSION_CODES.O)
#Override
protected Map<String, String> getParams() throws AuthFailureError {
String image = null;
image = NewBase64(encodeFileToBase64Binary);
String name1 = name.getText().toString().trim();
Map<String, String> params = new Hashtable<String, String>();
params.put(KEY_IMAGE, image);
params.put(KEY_NAME, name1);
return params;
}
};
}
You can convert PDF to base64 using below method
public String NewBase64(File mfile) {
ByteArrayOutputStream output = null;
try {
InputStream inputStream = null;
inputStream = new FileInputStream(mfile.getAbsolutePath());
byte[] buffer = new byte[8192];
int bytesRead;
output = new ByteArrayOutputStream();
Base64OutputStream output64 = new Base64OutputStream(output, Base64.DEFAULT);
while ((bytesRead = inputStream.read(buffer)) != -1) {
output64.write(buffer, 0, bytesRead);
}
output64.close();
} catch (IOException e) {
e.printStackTrace();
}
return output.toString();
}
So, I am downloading the profile picture from the Google SIgn-in api and I save it to a hidden file. The problem is that when I try to retrieve it, it throws me: D/skia: --- Failed to create image decoder with message 'unimplemented'. However when I retrieve an image from FireBaseStorage and save that one to the hidden file I can retrieve it whithout any problems.
I tried BitmapFactory.decodeByteArray(), but then I had a message telling me skia wasn't able to decode the file and it returned null.
The method I use to retrieve the profile picture and call the method that will save the file
private void getUsersPic() {
Bitmap profilePic;
try {
InputStream in = new URL(AppData.getUser().getPicture()).openConnection().getInputStream();
profilePic = BitmapFactory.decodeStream(in);
int size = profilePic.getRowBytes()*profilePic.getHeight();
ByteBuffer b = ByteBuffer.allocate(size);
byte[] bytes = new byte[size];
profilePic.copyPixelsToBuffer(b);
b.position(0);
b.get(bytes, 0, bytes.length);
SaveBitmapToFile.saveBitmap(bytes , AppData.getUser().getName()+AppData.getUser().getLastName());
} catch(Exception e) {
System.out.println("Get profile pic: "+e.toString());
}
}
Save the file
public static void saveBitmap(byte[] bitmap, String key) {
String path = AppData.getAppContext().getFilesDir()+"/.image"+"/";
File fileDir = new File(path);
if(!fileDir.isDirectory())
fileDir.mkdirs();
try {
File bitmapDir = new File(fileDir+"/"+key);
bitmapDir.createNewFile();
FileOutputStream stream = new FileOutputStream(bitmapDir);
stream.write(bitmap);
stream.close();
} catch (IOException e) {
System.out.println("Problem creating file "+e.toString()+ " Directory: "+fileDir);
}
}
Retrieve and return a bitmap
public static Bitmap getBitmap(String key) {
File file = new File(AppData.getAppContext().getFilesDir()+"/.image/"+key);
try {
BufferedInputStream buf = new BufferedInputStream(new FileInputStream(file));
return BitmapFactory.decodeStream(buf);//BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
} catch(Exception e) {
System.out.println("Exception getting bitmap: "+e.toString());
return null;
}
}
The last method should return a Bitmap and it is doing it. It is just not working when the image comes from the Google Sign-in api.
As pskink said in the comment of the post, I had to use compress() instead of copyPixelToBuffer(). Here is my updated method:
private void getUsersPic() {
Bitmap profilePic;
try {
InputStream in = new URL(AppData.getUser().getPicture()).openConnection().getInputStream();
profilePic = BitmapFactory.decodeStream(in);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
profilePic.compress(Bitmap.CompressFormat.PNG, 100, stream);
SaveBitmapToFile.saveBitmap(stream.toByteArray() , AppData.getUser().getName()+AppData.getUser().getLastName());
} catch(Exception e) {
System.out.println("Get profile pic: "+e.toString());
}
}
I'm accessing an external api and I'm expecting to get an image as response (byte[]). My method that connects to this endpoint looks like this:
private byte[] retrieveImage(String uri) {
byte[] imageBytes = null;
try {
URL url = new URL(uri);
BufferedImage bufferedImage = ImageIO.read(url);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ImageIO.write(image, "png", baos);
imageBytes = baos.toByteArray();
} catch (Exception ex) {
throw new ImageNotReadException(ex.getLocalizedMessage());
}
return imageBytes;
}
It turned out that if I pass the wrong parameters to the target endpoint I get this error message:
So basically I would like to throw the same error above but I also would like to throw an ImageNotReadException (java.lang.IllegalArgumentException: image == null! ) in case the program fails to read the image (byte[]). So basically, my method private byte[] retrieveImage(String uri) would have to throw my read image exception and the endpoint response exception.
Any tips?
Appreciate the help!
As i have commented see below options
private Response retrieveImage(String uri) {
byte[] imageBytes = null;
Response r=new Response();
try {
URL url = new URL(uri);
BufferedImage bufferedImage = ImageIO.read(url);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ImageIO.write(image, "png", baos);
imageBytes = baos.toByteArray();
r.setImage(imageBytes);
r.setStatus(1);
} catch (Exception ex) {
r.setStatus(0);
}
return r;
}
Response :
class Response{
String status;
byte[] image;
//getters setters
}
Or :
private Response retrieveImage(String uri)throws CustomException {
byte[] imageBytes = null;
try {
URL url = new URL(uri);
BufferedImage bufferedImage = ImageIO.read(url);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ImageIO.write(image, "png", baos);
imageBytes = baos.toByteArray();
} catch (Exception ex) {
throw new CustomException(ex.getLocalizedMessage());
}
return imageBytes;
}
How to display Base64 string in image on Java com.sun.net.httpserver.HttpServer ?
I run this code:
static class base implements HttpHandler{
#Override
public void handle(HttpExchange he) throws IOException {
byte[] name = Base64.getEncoder().encode(base64String.getBytes());
byte[] decodedString = Base64.getDecoder().decode(new String(name).getBytes("UTF-8"));
String base64String = "BASE64 IMAGE";
Headers headers = he.getResponseHeaders();
headers.add("Content-Type", "image/png");
File file = new File ("1.png");
//System.out.println(file);
FileInputStream fileInputStream = new FileInputStream(file);
InputStream bufferedInputStream = new ByteArrayInputStream(decodedString);
bufferedInputStream.read(decodedString, 0, decodedString.length);
he.sendResponseHeaders(200, decodedString.length);
final OutputStream os = he.getResponseBody();
os.write(decodedString);
os.close();
}
}
But displays a white cube