Develop Reference

Creating a File object from a resource

I have a file located at /res/introduced.xml. I know that I can access it in two ways:
1) the R.introduced resource
2) some absolute/relative URI
I'm trying to create a File object in order to pass it to a particular class. How do I do that?

This is what I ended up doing:
try{
InputStream inputStream = getResources().openRawResource(R.raw.some_file);
File tempFile = File.createTempFile("pre", "suf");
copyFile(inputStream, new FileOutputStream(tempFile));
// Now some_file is tempFile .. do what you like
} catch (IOException e) {
throw new RuntimeException("Can't create temp file ", e);
}
private void copyFile(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
int read;
while((read = in.read(buffer)) != -1){
out.write(buffer, 0, read);
}
}

some absolute/relative URI
Very few things in Android support that.
I'm trying to create a File object in order to pass it to a particular class. How do I do that?
You don't. A resource does not exist as a file on the filesystem of the Android device. Modify the class to not require a file, but instead take the resource ID, or an XmlResourceParser.

How to load a file from assets folder of my android test project?

Is there a way to get the file object of one of the files which are inside the assets folder. I know how to load the inputstream of such a file, but i need to have a file object instead of the inputstream.
This way i load the inputstream
InputStream in2 = getInstrumentation().getContext().getResources().getAssets().open("example.stf2");
But I need the file object, this way the file will not be found
File f = new File("assets/example.stf2");

Found a soltion which works in my case, mabye someone else can use this as well.
Retrieving the file from my android test project to an inputstream
InputStream input = getInstrumentation().getContext().getResources().getAssets().open("example.stf2");
Create a file on the External-Cachedir of the android application under test
File f = new File(getInstrumentation().getTargetContext().getExternalCacheDir() +"/test.txt");
Copy the inputstream to the new file
FileUtils.copyInputStreamToFile(input, f);
Now I can use this file for my further tests

try below code:-
AssetManager am = getAssets();
InputStream inputStream = am.open(file:///android_asset/myfoldername/myfilename);
File file = createFileFromInputStream(inputStream);
private File createFileFromInputStream(InputStream inputStream) {
try{
File f = new File(my_file_name);
OutputStream outputStream = new FileOutputStream(f);
byte buffer[] = new byte[1024];
int length = 0;
while((length=inputStream.read(buffer)) > 0) {
outputStream.write(buffer,0,length);
}
outputStream.close();
inputStream.close();
return f;
}catch (IOException e) {
//Logging exception
}
return null;
}
for more info see below link :-
How to pass a file path which is in assets folder to File(String path)?

mp3 not saving to sd correctly; how to save mp3 to sd card?

I've been looking at this site for the past 3 or so hours. How to copy files from 'assets' folder to sdcard?
This is the best I could come up with because I'm only trying to copy one file at a time.
InputStream in = null;
OutputStream out = null;
public void copyAssets() {
try {
in = getAssets().open("aabbccdd.mp3");
File outFile = new File(root.getAbsolutePath() + "/testf0lder");
out = new FileOutputStream(outFile);
copyFile(in, out);
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch (IOException e) {
Log.e("tag", "Failed to copy asset file: ", e);
}
}
private void copyFile(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) != -1) {
out.write(buffer, 0, read);
}
}
I've figured out how to create a file and save a text file. http://eagle.phys.utk.edu/guidry/android/writeSD.html
I would rather save an mp3 file to the sdcard rather than a text file.
When I use this code I provided, I get a text document that same size as the aabbccdd.mp3 file. It does not create a folder and save an .mp3 file. It saves a text document in the root folder. When you open it, I see a whole bunch of chinese letters, but at the top in English I can see the words WireTap. WireTap Pro was the program I used to record the sound so I know the .mp3 is passing through. It's just not creating a folder and then saving a file like the above .edu example.
What should I do?

I think you should do something like that -[Note: this i used for some other formats not mp3 but its works on my app for multiple format so i hope it will work for u too.]
InputStream in = this.getAssets().open("tmp.mp3"); //give path as per ur app
byte[] data = getByteData(in);
Make sure u have the folder already exists on path, if folder is not there it will not save content correctly.
byteArrayToFile(data , "testfolder/tmp.mp3"); //as per ur sdcard path, modify it.
Now the methods ::
1) getByteData from inputstream -
private byte[] getByteData(InputStream is)
{
byte[] buffer= new byte[1024]; /* or some other number */
int numRead;
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
try{
while((numRead = is.read(buffer)) > 0) {
bytes.write(buffer, 0, numRead);
}
return bytes.toByteArray();
}
catch(Exception e)
{ e.printStackTrace(); }
return new byte[0];
}
2) byteArrayToFile
public void byteArrayToFile(byte[] byteArray, String outFilePath){
FileOutputStream fos;
try {
fos = new FileOutputStream(outFilePath);
fos.write(byteArray);
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
}

Load the pdf file in app from assets

I have a PDF file stored in my assets. I want to load the PDF from my assets and read it in the app itself without using any 3rd party app to view.
I got the solution in this link. It works fine when selecting files from sdcard.

Following snippet might help you accessing files from asset folder and then open it:
private void ReadFromAssets()
{
AssetManager assetManager = getAssets();
InputStream in = null;
OutputStream out = null;
File file = new File(getFilesDir(), "file.pdf");
try
{
in = assetManager.open("file.pdf");
out = openFileOutput(file.getName(), Context.MODE_WORLD_READABLE);
copyFile(in, out);
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch (Exception e)
{
Log.e("tag", e.getMessage());
}
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(
Uri.parse("file://" + getFilesDir() + "/file.pdf"),
"application/pdf");
startActivity(intent);
}
and copyFile method is as follows:
private void copyFile(InputStream in, OutputStream out) throws IOException
{
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) != -1)
{
out.write(buffer, 0, read);
}
}
EDIT
For that purpose you'll have to use an ecternal library. It's explained quite well in the link below:
Render a PDF file using Java on Android
Hope this will help you.

Its better if you can open it using a webview
WebView web = (WebView) findViewById(R.id.webView1);
web.loadUrl("file:///android_asset/yourpdf.pdf");
Hope it works.
Ooops just now I checked, the pdf cannot be loaded in the web view
Sorry

How to create a independent and full copy of a File object?

Official facebook App has a bug, when you try to share an image with share intent, the image gets deleted from the sdcard. This is the way you have to pass the image to facebook app using the uri of the image:
File myFile= new File(Environment.getExternalStorageDirectory(), "car.jpg");
Uri uri = Uri.fromFile(myFile);
i.putExtra(Intent.EXTRA_STREAM, uri);
Then, suppose that if i create a copy from the original myFile object, and i pass the uri of the copy to facebook app, then, my original image will not be deleted.
I tried with this code, but it doesn't work, the original image file is still getting deleted:
File myFile= new File(Environment.getExternalStorageDirectory(), "car.jpg");
File auxFile=myFile.getAbsoluteFile();
Uri uri = Uri.fromFile(auxFile);
Can someone tell me how to do a exact copy of a file that doesn't redirect to the original File?

Please check: Android file copy
The file is copied byte by byte so no reference to the old file is maintained.

Here, this should be able to create a copy of your file:
private void CopyFile() {
InputStream in = null;
OutputStream out = null;
try {
in = new FileInputStream(<file path>);
out = new FileOutputStream(<output path>);
copyFile(in, out);
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch(Exception e) {
Log.e("tag", e.getMessage());
}
}
private void copyFile(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
int read;
while((read = in.read(buffer)) != -1){
out.write(buffer, 0, read);
}
}