I need to read a json file from the SD card and display the data in the spinner. Is there any way to read the data from file in Android and display the contents of that file in spinner?
First read the file from SD card and then parse that file
Step-1
Retrieve the data from file from SD card. see tutorial
Step-2
Parse the data. See How to parse JSON String
Sample code
try {
File dir = Environment.getExternalStorageDirectory();
File yourFile = new File(dir, "path/to/the/file/inside/the/sdcard.ext");
FileInputStream stream = new FileInputStream(yourFile);
String jString = null;
try {
FileChannel fc = stream.getChannel();
MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
/* Instead of using default, pass in a decoder. */
jString = Charset.defaultCharset().decode(bb).toString();
}
finally {
stream.close();
}
JSONObject jObject = new JSONObject(jString);
} catch (Exception e) {e.printStackTrace();}
Related
I have a text file in folder res/raw name "pass.txt" and some data in it i want to delete this data and enter new data in it.... is it possible to write data on it?? otherwise what is correct path to store my text file so i can easily read/write data on it.... and what is the code to read and write data from it?? below is the code through which i can only read data from this text file
InputStream fr = getResources().openRawResource(R.raw.pass);
BufferedReader br = new BufferedReader(new InputStreamReader(fr));
String s=br.readLine().toString().trim();
Resources contained in your raw directory in your project will be packaged inside your APK and will not be writeable at runtime.
Look at Internal or External Data Storage APIs to read write files.
https://developer.android.com/training/basics/data-storage/files.html
you can use Android internal storage to Read and write file ... as res/raw is only Read only..you can not change content at runtime.
Here is the code:
Create file
String MY_FILE_NAME = “mytextfile.txt”;
// Create a new output file stream
FileOutputStream fileos = openFileOutput(MY_FILE_NAME, Context.MODE_PRIVATE);
// Create a new file input stream.
FileInputStream fileis = openFileInput(My_FILE_NAME);
Read from file:
public void Read(){
static final int READ_BLOCK_SIZE = 100;
try {
FileInputStream fileIn=openFileInput("mytextfile.txt");
InputStreamReader InputRead= new InputStreamReader(fileIn);
char[] inputBuffer= new char[READ_BLOCK_SIZE];
String s="";
int charRead;
while ((charRead=InputRead.read(inputBuffer))>0) {
// char to string conversion
String readstring=String.copyValueOf(inputBuffer,0,charRead);
s +=readstring;
}
InputRead.close();
Toast.makeText(getBaseContext(), s,Toast.LENGTH_SHORT).show();
} catch (Exception e) {
e.printStackTrace();
}
}
Write to file:
public void Write(){
try {
FileOutputStream fileout=openFileOutput("mytextfile.txt", MODE_PRIVATE);
OutputStreamWriter outputWriter=new OutputStreamWriter(fileout);
outputWriter.write("TEST STRING..");
outputWriter.close();
//display file saved message
Toast.makeText(getBaseContext(), "File saved successfully!",
Toast.LENGTH_SHORT).show();
} catch (Exception e) {
e.printStackTrace();
}
}
I am developing an Android app. In my app, I am uploading multiple images to server using Retrofit network library. Before I uploading file I create a temporary file from bitmaps. Then delete them after uploaded.
photoFiles = new ArrayList<File>();
MultipartBody.Builder requestBodyBuilder = new MultipartBody.Builder().setType(MultipartBody.FORM);
int index = 0;
for(Bitmap bitmap: previewBitmaps)
{
File file = null;
try{
String fileName = String.valueOf(System.currentTimeMillis())+".jpeg";
file = new File(Environment.getExternalStorageDirectory(), fileName); // create temporary file start from here
if(file.exists())
{
file.delete();
}
OutputStream os = new BufferedOutputStream(new FileOutputStream(file));
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, os);
os.close();
photoFiles.add(file);
requestBodyBuilder.addFormDataPart("files",file.getName(), RequestBody.create(MediaType.parse("image/png"),file));
}
catch (Exception e)
{
Toast.makeText(getBaseContext(),e.getMessage(),Toast.LENGTH_SHORT).show();
}
index++;
}
//Upload process goes here and delete files back after upload
Using above code, all working fine. But the problem is I have to create temporary files. I do not want to create temporary files. What I want to do is I create array list of Uri string when I pick up the file. Then on file upload, I will convert them to file back and do the upload process.
photoFiles = new ArrayList<File>();
MultipartBody.Builder requestBodyBuilder = new MultipartBody.Builder().setType(MultipartBody.FORM);
int index = 0;
for(Bitmap bitmap: previewBitmaps)
{
File file = null;
try{
Uri uri = Uri.parse(photosUriStrings.get(index));
file = new File(getPathFromUri(uri));
Toast.makeText(getBaseContext(),getPathFromUri(uri),Toast.LENGTH_SHORT).show();
photoFiles.add(file);
requestBodyBuilder.addFormDataPart("files",file.getName(), RequestBody.create(MediaType.parse("image/png"),file));
}
catch (Exception e)
{
Toast.makeText(getBaseContext(),e.getMessage(),Toast.LENGTH_SHORT).show();
}
index++;
}
As you can see in the above, I am converting the URI string back to file and then upload it. But this time retrofit unable to upload the file. File is not null as well. So I am pretty sure the error is with converting uri string back to image file back because my old code above working fine. Why can I not do that? How can I successfully convert from URI to image file back please?
I found this
Convert file: Uri to File in Android
and
Create File from Uri type android
both not working.
I am not clear about your question but I think this may help you. This single line code will help you to convert URI to file and show in your view.
Picasso.with(getContext()).load("URI path").into(holder.imgID);
I am trying to save a p12 file to internal storage like so:
File file = new File(mContext.getFilesDir(), "fileName.p12");
I then proceed to read this file into a byte array like so:
byte[] bFile = new byte[(int) file.length()];
try {
bFile = org.apache.commons.io.FileUtils.readFileToByteArray(file);
}catch(Exception e){
e.printStackTrace();
}
After doing this, I get a FileNotFoundException even though the debugger shows that the file is saved in /data/data/com.fm.sg.android/files/fileName.p12
What am I doing wrong?
path = context.getFilesDir().getAbsolutePath().toString();
String filename = "fileName.p12";
File file = new File(path,filename);
then the rest of your code....this should make it...
I have a layout where I have an Edit Text field where I enter my data.
I have 2 buttons.Save and Plot.
When I press save I want to save the data (in xls format) from edittext field and the current date in sd card.
When I press the plot ,I want to plot them.
To save data:
case R.id.savebtn:
savefunc();
break;
...
public void savefunc(){
//saving
File sdCard = Environment.getExternalStorageDirectory();
File directory = new File (sdCard, "MyFiles");
directory.mkdirs();
File file = new File(directory, filename);
try {
FileOutputStream fOut = new FileOutputStream(file);
DataOutputStream os = new DataOutputStream(fOut);
os.writeUTF(thedata);
os.writeUTF(mydate);
os.close();
} catch (FileNotFoundException e) {
// handle exception
} catch (IOException e) {
// handle exception
}
}
For reading:
public void readfunc(){
File sdCard = Environment.getExternalStorageDirectory();
File directory = new File (sdCard, "MyFiles");
File file = new File(directory, filename);
try{
FileInputStream fIn = new FileInputStream(file);
DataInputStream is = new DataInputStream(fIn);
String name = is.readUTF();
String content = is.readUTF();
is.close();
} catch (FileNotFoundException e) {
// handle exception
} catch (IOException e) {
// handle exception
}
}
and :
case R.id.savebtn:
savefunc();
break;
case R.id.graphicsbtn:
readfunc();
...
But the xls file asks me format , I choose UTF8 and it is empty.
If I leave it shows chinese characters.
I am not sure about the "reading" part of the code.
Read this documentation here have more information about save data to external storage and read it is:
Saving and Reading file from External storage
Ok, I found this and works fine!
I have downloaded a file from HttpConnection using the FileOutputStream in android and now its being written in phone's internal memory on path as i found it in File Explorer
/data/data/com.example.packagename/files/123.ics
Now, I want to open & read the file content from phone's internal memory to UI. I tried to do it by using the FileInputStream, I have given just filename with extension to open it but I am not sure how to mention the file path for file in internal memory,as it forces the application to close.
Any suggestions?
This is what I am doing:
try
{
FileInputStream fileIn;
fileIn = openFileInput("123.ics");
InputStream in = null;
EditText Userid = (EditText) findViewById(R.id.user_id);
byte[] buffer = new byte[1024];
int len = 0;
while ( (len = in.read(buffer)) > 0 )
{
Userid.setText(fileIn.read(buffer, 0, len));
}
fileIn.close();
} catch (FileNotFoundException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
String filePath = context.getFilesDir().getAbsolutePath();//returns current directory.
File file = new File(filePath, fileName);
Similar post here
read file from phone memory
If the file is where you say it is, and your application is com.example.packagename, then calling openFileInput("123.ics"); will return you a FileInputStream on the file in question.
Or, call getFilesDir() to get a File object pointing to /data/data/com.example.packagename/files, and work from there.
I am using this code to open file in internal storage. i think i could help.
File str = new File("/data/data/com.xlabz.FlagTest/files/","hello_file.xml");