I need to download a single image at time from the Internet and then save it on the SD card. How do I do it? I have made an attempt, but when I try to view that downloaded image, it shows the message, "No Preview Available". Please see my code below:
public class ImgDownloader {
private static final int IO_BUFFER_SIZE = 4 * 1024;
public static final byte[] downloadImage(String imgURL) {
byte[] data = null;
try {
Log.v("Down", "1");
InputStream in = null;
BufferedOutputStream out = null;
in = new BufferedInputStream(new URL(imgURL).openStream(), 8 * 1024);
Log.v("Down", "2");
final ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE);
copy(in, out);
out.flush();
Log.v("Down", "3");
data = dataStream.toByteArray();
// bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
Log.v("Down", "4");
} catch (Exception ex) {
ex.printStackTrace();
// System.out.println("Exception in Image Downloader .."
// +ex.getMessage());
}
return data;
}
private static void copy(InputStream in, OutputStream out)
throws IOException {
byte[] b = new byte[IO_BUFFER_SIZE];
int read;
while ((read = in.read(b)) != -1) {
out.write(b, 0, read);
}
}
}
Note:
i have download the image from the SSL connection.
Any ideas? Thanks in advance.
You can try something like
try{
URL url = new URL(downloadUrl); //you can write here any link
File file = new File(absolutePath); //Something like ("/sdcard/file.mp3")
//Create parent directory if it doesn't exists
if(!new File(file.getParent()).exists())
{
System.out.println("Path is created " + new File(file.getParent()).mkdirs());
}
file = new File(absolutePath); //Something like ("/sdcard/file.mp3")
file.createNewFile();
/* Open a connection to that URL. */
URLConnection ucon = url.openConnection();
/*
* Define InputStreams to read from the URLConnection.
*/
InputStream is = ucon.getInputStream();
/*
* Read bytes to the Buffer until there is nothing more to read(-1).
*/
FileOutputStream fos = new FileOutputStream(file);
int size = 1024*1024;
byte[] buf = new byte[size];
int byteRead;
while (((byteRead = is.read(buf)) != -1)) {
fos.write(buf, 0, byteRead);
bytesDownloaded += byteRead;
}
/* Convert the Bytes read to a String. */
fos.close();
}catch(IOException io)
{
networkException = true;
continueRestore = false;
}
catch(Exception e)
{
continueRestore = false;
e.printStackTrace();
}
Make the appropriate changes according to your requirement. I use the same code for downloading files from internet and saving it to SDCard.
Hope it helps !!
Related
Hi have implemented programatically downloading of file using inputstream and cipheroutputstream(for encryption). The download is happening very slow. Whereas if i try to download via download manager, it is very fast. What can i do to improve my code and increase the download speed of the file. Below is my code.
private void saveFileUsingEncryption(String aMineType, long length) throws Exception {
int bufferSize = 1024*4;
//byte[] buffer = new byte[1024];
byte[] buffer = new byte[bufferSize];
int bytesRead = 0;
long totalRead = 0;
FileOutputStream outStream = null;
File f = new File(Constants.DWLPATH);
if (!f.exists()) {
f.mkdirs();
}
try {
Cipher aes = Cipher.getInstance("ARC4");
aes.init(Cipher.ENCRYPT_MODE, new SecretKeySpec("mykey".getBytes(), "ARC4"));
if(contDisp==null || contDisp.length()==0) {
// downloadFileName = downloadFileName.replaceAll("[^a-zA-Z0-9_]+", "");
downloadFileName = downloadFileName + "." + getFileExtension(aMineType);
}
outStream = new FileOutputStream(Constants.DWLPATH + downloadFileName,true);
CipherOutputStream out = new CipherOutputStream(outStream, aes);
while ((bytesRead = inputStream.read(buffer, 0, bufferSize)) >= 0) {
out.write(buffer, 0, bytesRead);
try{
// Adjust this value. It shouldn't be too small.
Thread.sleep(50);
}catch (InterruptedException e){
TraceUtils.logException(e);
}
totalRead += bytesRead;
sb=sb.append("\n Total bytes Read:"+totalRead);
Log.e("--",sb.toString());
/* if (this.length > 0) {
Long[] progress = new Long[5];
progress[0] = (long) ((double) totalRead / (double) this.length * 100.0);
publishProgress(progress);
}*/
if (this.isCancelled()) {
if (conn != null)
conn.disconnect();
conn = null;
break;
}
}
Log.e("Download completed","success");
out.flush();
//Utils.putDownloadLogs(requestUrl,mimeType,length, downloadFileName,"Download is Successful",sb.toString(), context);
outStream.close();
buffer = null;
} catch (Exception e) {
TraceUtils.logException( e);
file_newsize = storedFileSizeInDB + totalRead;
if (totalFileSize == 0)
totalFileSize = length;
callback.onRequestInterrupted(file_newsize,totalFileSize);
StringWriter errors = new StringWriter();
e.printStackTrace(new PrintWriter(errors));
// Utils.putDownloadLogs(requestUrl,mimeType,length,downloadFileName,"failure---" + errors.toString(),sb.toString(), context);
throw e;
} finally {
if (outStream != null)
outStream.close();
outStream = null;
}
}
You can use default download manager to download the file because its very easy to implement and provide better features like respond to the internet connection , provide accessibility to add notification in status bar , by running the query on download manager object you can find the total bytes and remaining bytes so you can calculate the progress and after completion of download by tapping the notification one can perform the desired operation.
And also there are many libraries are available for to achieve this like
PRDOWNLOADER
FetchDownloader
This libraires provide you the feature of pause,download, resume download , tracking the progress and cancel download
Also you can customize it as per your need.
Here is the DownloadAndEncryptFileTask.class to download with encryption
public class DownloadAndEncryptFileTask extends AsyncTask<Void, Void, Void> {
private String mUrl;
private File mFile;
private Cipher mCipher;
InputStream inputStream;
FileOutputStream fileOutputStream;
CipherOutputStream cipherOutputStream;
public DownloadAndEncryptFileTask(String url, File file, Cipher cipher) {
if (url == null || url.isEmpty()) {
throw new IllegalArgumentException("You need to supply a url to a clear MP4 file to download and encrypt, or modify the code to use a local encrypted mp4");
}
mUrl = url;
mFile = file;
mCipher = cipher;
}
private void downloadAndEncrypt() throws Exception {
URL url = new URL(mUrl);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
if (mFile.length() > 0) {
connection.setRequestProperty("Range", "bytes=" + mFile.length() + "-");
}
connection.connect();
Log.e("length", mFile.length() + "");
if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
throw new IOException("server error: " + connection.getResponseCode() + ", " + connection.getResponseMessage());
}
inputStream = connection.getInputStream();
if (mFile.length() > 0) {
//connection.connect();
fileOutputStream = new FileOutputStream(mFile, true);
} else {
fileOutputStream = new FileOutputStream(mFile);
}
CipherOutputStream cipherOutputStream = new CipherOutputStream(fileOutputStream, mCipher);
byte buffer[] = new byte[1024 * 1024];
int bytesRead;
while ((bytesRead = inputStream.read(buffer)) != -1) {
Log.d(getClass().getCanonicalName(), "reading from http...");
cipherOutputStream.write(buffer, 0, bytesRead);
}
inputStream.close();
cipherOutputStream.close();
connection.disconnect();
}
#Override
protected Void doInBackground(Void... params) {
try {
downloadAndEncrypt();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
Log.d(getClass().getCanonicalName(), "done");
}
}
Call this class
new DownloadAndEncryptFileTask(
myFeedsModel.getVideo().getVideo360(),
new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), myFeedsModel.getFile_name()),
OBJECT OF YOUR CIPHER
I'm new at android development and I'm creating simple bluetooth app that can receive xml file and save xml file values to database. But how can I receive xml file from bytes array? Is it possible? After searchinf I found this question and based ont that question I try to save byte array to file. But how I need to test it? I can't find my file in my phone.
case Constants.MESSAGE_READ:
byte[] readBuffer = (byte[]) msg.obj;
try {
String path = activity.getFilesDir() + "/myFile.xml";
Log.d("MuTestClass", path);
FileOutputStream stream = new FileOutputStream(path);
stream.write(readBuffer);
stream.close();
} catch (Exception e1) {
e1.printStackTrace();
}
break;
You can use:
class Utils{
public static InputStream openFile(String filename) throws IOException{
AssetManager assManager = getApplicationContext().getAssets();
InputStream is = null;
is = assManager.open(filename);
return new BufferedInputStream(is);
}
public static byte[] readBytes(InputStream inputStream) throws IOException {
ByteArrayOutputStream byteBuffer = new ByteArrayOutputStream();
int bufferSize = 1024;
byte[] buffer = new byte[bufferSize];
int len = 0;
while ((len = inputStream.read(buffer)) != -1) {
byteBuffer.write(buffer, 0, len);
}
return byteBuffer.toByteArray();
}
}
like this:
try {
Utils.readBytes(Utils.openFile("something.xml"));
} catch (IOException e) {
e.printStackTrace();
}
This is a code for saving images in SD card if and if not exist.
but i don't know how to read it.
Can anybody help me please.
This is the download file method:
public static String DownLoadFile(String netUrl, String name ) {
try {
//need uses permission WRITE_EXTERNAL_STORAGE
ByteArrayBuffer baf = null;
long startTime = 0;
//get to directory (a File object) from SD Card
File savePath=new File(Environment.getExternalStorageDirectory().getPath()+"/postImages/");
String ext="jpg";
URL url = new URL(netUrl);
//create your specific file for image storage:
File file = new File(savePath, name + "." + ext);
boolean success = true;
if (!savePath.exists()) {
success = savePath.mkdir();
}
if (success) {
if(file.createNewFile())
{
file.createNewFile();
//write the Bitmap
Log.i("file existence", "file does not exist!!!!!!!!!!!");
/* Open a connection to that URL. */
URLConnection ucon = url.openConnection();
InputStream is = ucon.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
startTime = System.currentTimeMillis();
baf = new ByteArrayBuffer(5000);
int current = 0;
while ((current = bis.read()) != -1) {
baf.append((byte) current);
}
/* Convert the Bytes read to a String. */
FileOutputStream fos = new FileOutputStream(file);
fos.write(baf.toByteArray());
fos.flush();
fos.close();
Log.d("DownloadManager", "download ready in" + ((System.currentTimeMillis() - startTime) / 1000) + " sec");
return file.getAbsolutePath();
}//end of create file if not exists
}//end of if success
} catch (Exception exx) {
if (exx.getMessage() != null) {
} else {
}
}
return null;
}
Try this,
Uri uri = Uri.parse("file:///sdcard/temporary_file.jpg");
img.setImageURI(uri);
if u have image uri so get path from uri like
String Path = fileUri.getPath();
// read file from sdcard
public static byte[] readFromStream(String path) throws Exception { File
file = new File(path); InputStream inputStream = new
FileInputStream(file); ByteArrayOutputStream baos = new
ByteArrayOutputStream(); DataOutputStream dos = new
DataOutputStream(baos); byte[] data = new byte[(int) file.length()]; int
count = inputStream.read(data); while (count != -1) { dos.write(data, 0,
count); count = inputStream.read(data); } return baos.toByteArray(); }
I currently have two activities. One for pulling the image from the SD card and one for Bluetooth connection.
I have utilized a Bundle to transfer the Uri of the image from activity 1.
Now what i wish to do is get that Uri in the Bluetooth activity to and convert it into a transmittable state via Byte Arrays i have seen some examples but i can't seem to get them to work for my code!!
Bundle goTobluetooth = getIntent().getExtras();
test = goTobluetooth.getString("ImageUri");
is what i have to pull it across. What would be the next step?
From Uri to get byte[] I do the following things,
InputStream iStream = getContentResolver().openInputStream(uri);
byte[] inputData = getBytes(iStream);
and the getBytes(InputStream) method is:
public byte[] getBytes(InputStream inputStream) throws IOException {
ByteArrayOutputStream byteBuffer = new ByteArrayOutputStream();
int bufferSize = 1024;
byte[] buffer = new byte[bufferSize];
int len = 0;
while ((len = inputStream.read(buffer)) != -1) {
byteBuffer.write(buffer, 0, len);
}
return byteBuffer.toByteArray();
}
Kotlin is very concise here:
#Throws(IOException::class)
private fun readBytes(context: Context, uri: Uri): ByteArray? =
context.contentResolver.openInputStream(uri)?.buffered()?.use { it.readBytes() }
Kotlin has convenient extension functions for InputStream like buffered,use , and readBytes.
buffered decorates the input stream as BufferedInputStream
use handles closing the stream
readBytes does the main job of reading the stream and writing into a byte array
Error cases:
IOException can occur during the process (like in Java)
openInputStream can return null. If you call the method in Java you can easily oversee this. Think about how you want to handle this case.
Syntax in kotlin
val inputData = contentResolver.openInputStream(uri)?.readBytes()
Java best practice: never forget to close every stream you open!
This is my implementation:
/**
* get bytes array from Uri.
*
* #param context current context.
* #param uri uri fo the file to read.
* #return a bytes array.
* #throws IOException
*/
public static byte[] getBytes(Context context, Uri uri) throws IOException {
InputStream iStream = context.getContentResolver().openInputStream(uri);
try {
return getBytes(iStream);
} finally {
// close the stream
try {
iStream.close();
} catch (IOException ignored) { /* do nothing */ }
}
}
/**
* get bytes from input stream.
*
* #param inputStream inputStream.
* #return byte array read from the inputStream.
* #throws IOException
*/
public static byte[] getBytes(InputStream inputStream) throws IOException {
byte[] bytesResult = null;
ByteArrayOutputStream byteBuffer = new ByteArrayOutputStream();
int bufferSize = 1024;
byte[] buffer = new byte[bufferSize];
try {
int len;
while ((len = inputStream.read(buffer)) != -1) {
byteBuffer.write(buffer, 0, len);
}
bytesResult = byteBuffer.toByteArray();
} finally {
// close the stream
try{ byteBuffer.close(); } catch (IOException ignored){ /* do nothing */ }
}
return bytesResult;
}
use getContentResolver().openInputStream(uri) to get an InputStream from a URI. and then read the data from inputstream convert the data into byte[] from that inputstream
Try with following code
public byte[] readBytes(Uri uri) throws IOException {
// this dynamically extends to take the bytes you read
InputStream inputStream = getContentResolver().openInputStream(uri);
ByteArrayOutputStream byteBuffer = new ByteArrayOutputStream();
// this is storage overwritten on each iteration with bytes
int bufferSize = 1024;
byte[] buffer = new byte[bufferSize];
// we need to know how may bytes were read to write them to the byteBuffer
int len = 0;
while ((len = inputStream.read(buffer)) != -1) {
byteBuffer.write(buffer, 0, len);
}
// and then we can return your byte array.
return byteBuffer.toByteArray();
}
Refer this LINKs
This code works for me
Uri selectedImage = imageUri;
getContentResolver().notifyChange(selectedImage, null);
ImageView imageView = (ImageView) findViewById(R.id.imageView1);
ContentResolver cr = getContentResolver();
Bitmap bitmap;
try {
bitmap = android.provider.MediaStore.Images.Media
.getBitmap(cr, selectedImage);
imageView.setImageBitmap(bitmap);
Toast.makeText(this, selectedImage.toString(),
Toast.LENGTH_LONG).show();
finish();
} catch (Exception e) {
Toast.makeText(this, "Failed to load", Toast.LENGTH_SHORT)
.show();
e.printStackTrace();
}
public void uriToByteArray(String uri)
{
ByteArrayOutputStream baos = new ByteArrayOutputStream();
FileInputStream fis = null;
try {
fis = new FileInputStream(new File(uri));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
byte[] buf = new byte[1024];
int n;
try {
while (-1 != (n = fis.read(buf)))
baos.write(buf, 0, n);
} catch (IOException e) {
e.printStackTrace();
}
byte[] bytes = baos.toByteArray();
}
Use the following method to create a bytesArray from a URI in Android studio.
public byte[] getBytesArrayFromURI(Uri uri) {
try {
InputStream inputStream = getContentResolver().openInputStream(uri);
ByteArrayOutputStream byteBuffer = new ByteArrayOutputStream();
int bufferSize = 1024;
byte[] buffer = new byte[bufferSize];
int len = 0;
while ((len = inputStream.read(buffer)) != -1) {
byteBuffer.write(buffer, 0, len);
}
return byteBuffer.toByteArray();
}catch(Exception e) {
Log.d("exception", "Oops! Something went wrong.");
}
return null;
}
I am loading a image from the web to the local android phone. The code that I have for writing to a file is as follows
BufferedInputStream bisMBImage=null;
InputStream isImage = null;
URL urlImage = null;
URLConnection urlImageCon = null;
try
{
urlImage = new URL(imageURL); //you can write here any link
urlImageCon = urlImage.openConnection();
isImage = urlImageCon.getInputStream();
bisMBImage = new BufferedInputStream(isImage);
int dotPos = imageURL.lastIndexOf(".");
if (dotPos > 0 )
{
imageExt = imageURL.substring(dotPos,imageURL.length());
}
imageFileName = PATH + "t1" + imageExt;
File file = new File(imageFileName);
if (file.exists())
{
file.delete();
Log.d("FD",imageFileName + " deleted");
}
ByteArrayBuffer baf = new ByteArrayBuffer(255);
Log.d("IMAGEWRITE", "Start to write image to Disk");
int current = 0;
try
{
while ((current = bisMBImage.read()) != -1)
{
baf.append((byte) current);
}
FileOutputStream fos = new FileOutputStream(file);
fos.write(baf.toByteArray());
fos.close();
Log.d("IMAGEWRITE", "Image write to Disk done");
}
catch (IOException e)
{
e.printStackTrace();
}
isImage.close();
}
catch (IOException e)
{
Log.d("DownloadImage", "Error: " + e);
}
finally
{
isImage = null;
urlImageCon = null;
urlImage = null;
}
For some reason the whole writing to a file takes 1 minute. Is there a way I can optimize this ?
Your buffer is very small: 255 bytes. You could make it 1024 times bigger (255 kilobytes). This is an acceptable size and this would certainly speed up the thing.
Also, this is very slow as it reads the bytes one by one:
while ((current = bisMBImage.read()) != -1) {
baf.append((byte) current);
}
You should try using the array version of read() instead: read(byte[] buffer, int offset, int byteCount) with an array as large as what I have described above.
You should use the Android HttpClient for file fetching over the java URL Connection. Also your Buffer is very small.
Try this snipped:
FileOutputStream f = new FileOutputStream(new File(root,"yourfile.dat"));
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpGet request = new HttpGet(urlString);
HttpResponse response = httpClient.execute(request);
InputStream is = response.getEntity().getContent();
byte[] buffer = new byte[1024];
int len1 = 0;
while ( (len1 = is.read(buffer)) > 0 ) {
f.write(buffer,0, len1);
}
f.close();