Develop Reference

FileInputStream doesn't access the file [duplicate]

I have a resource file in my /res/raw/ folder (/res/raw/textfile.txt) which I am trying to read from my android app for processing.
public static void main(String[] args) {
File file = new File("res/raw/textfile.txt");
FileInputStream fis = null;
BufferedInputStream bis = null;
DataInputStream dis = null;
try {
fis = new FileInputStream(file);
bis = new BufferedInputStream(fis);
dis = new DataInputStream(bis);
while (dis.available() != 0) {
// Do something with file
Log.d("GAME", dis.readLine());
}
fis.close();
bis.close();
dis.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
I have tried different path syntax but always get a java.io.FileNotFoundException error. How can I access /res/raw/textfile.txt for processing? Is File file = new File("res/raw/textfile.txt"); the wrong method in Android?
***** Answer: *****
// Call the LoadText method and pass it the resourceId
LoadText(R.raw.textfile);
public void LoadText(int resourceId) {
// The InputStream opens the resourceId and sends it to the buffer
InputStream is = this.getResources().openRawResource(resourceId);
BufferedReader br = new BufferedReader(new InputStreamReader(is));
String readLine = null;
try {
// While the BufferedReader readLine is not null
while ((readLine = br.readLine()) != null) {
Log.d("TEXT", readLine);
}
// Close the InputStream and BufferedReader
is.close();
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
Note this will return nothing, but will print the contents line by line as a DEBUG string in the log.

If you have a file in res/raw/textfile.txt from your Activity/Widget call:
getResources().openRawResource(...) returns an InputStream
The dots should actually be an integer found in R.raw... corresponding to your filename, possibly R.raw.textfile (it's usually the name of the file without extension)
new BufferedInputStream(getResources().openRawResource(...)); then read the content of the file as a stream

Download file from webserver and read content on android

I am learning Android and porting my Windows app to Android platform. I need an advice how to download a small text file and read content of this file.
I have following code in my Windows app, I need to rewrite it for Android app:
string contents = "file.txt";
string neturl = "http://www.example.com/file.txt";
HttpClient client = new HttpClient();
try {
HttpResponseMessage message = await client.GetAsync(neturl);
StorageFolder folderForFile = Windows.Storage.ApplicationData.Current.LocalFolder;
StorageFile fileWithContent = await folderForFile.CreateFileAsync(channels, CreationCollisionOption.ReplaceExisting);
byte[] bytesToWrite = await message.Content.ReadAsByteArrayAsync();
await FileIO.WriteBytesAsync(fileWithContent, bytesToWrite);
var file = await folderForFile.GetFileAsync(contents);
var text = await FileIO.ReadLinesAsync(file);
foreach (var textItem in text)
{
string[] words = textItem.Split(',');
...
I have found what on Android I need to create following class for async download
public class DownloadFileFromURL extends AsyncTask<String, String, String> {
/**
* Downloading file in background thread
* */
#Override
protected String doInBackground(String... f_url) {
int count;
try {
URL url = new URL(f_url[0]);
URLConnection conection = url.openConnection();
conection.connect();
// download the file
InputStream input = new BufferedInputStream(url.openStream(), 8192);
// Output stream
OutputStream output = new FileOutputStream("file.txt");
byte data[] = new byte[1024];
while ((count = input.read(data)) != -1) {
// writing data to file
output.write(data, 0, count);
}
// flushing output
output.flush();
// closing streams
output.close();
input.close();
} catch (Exception e) {
Log.e("Error: ", e.getMessage());
}
return null;
}
In the code above I try to download file and name it as "file.txt", but get exception 'FileNotFoundException file.txt open failed: EROFS (Read-only file system)", I need to save it internally (I do not want to let users to see this file in the file explorers) and rewrite file if it exists.
And I try to execute this task and read file
void DownloadAndReadContent() {
new DownloadFileFromURL().execute("http://www.example.com/file.txt");
try {
BufferedReader br = new BufferedReader(new InputStreamReader(openFileInput("file.txt")));
String str = "";
while ((str = br.readLine()) != null) {
Log.d(LOG_TAG, str);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}

so downloading to SD card is working
protected String doInBackground(String... f_url) {
int count;
try {
URL url = new URL(f_url[0]);
URLConnection conection = url.openConnection();
conection.connect();
InputStream input = new BufferedInputStream(url.openStream(), 8192);
File SDCardRoot = Environment.getExternalStorageDirectory();
SDCardRoot = new File(SDCardRoot.getAbsolutePath() + "/plus");
SDCardRoot.mkdir();
File file = new File(SDCardRoot,"settings.dat");
FileOutputStream output = new FileOutputStream(file);
byte data[] = new byte[1024];
while ((count = input.read(data)) != -1) {
output.write(data, 0, count);
}
output.flush();
output.close();
input.close();
} catch (Exception e) {
Log.e("Error: ", e.getMessage());
}
return null;
}
and reading:
new DownloadFileFromURL().execute("http://www.example.com/file.txt");
if (!Environment.getExternalStorageState().equals(
Environment.MEDIA_MOUNTED)) {
Log.d(LOG_TAG, "SD n\a " + Environment.getExternalStorageState());
return;
}
File sdPath = Environment.getExternalStorageDirectory();
sdPath = new File(sdPath.getAbsolutePath() + "/plus");
File sdFile = new File(sdPath, "settings.dat");
try {
BufferedReader br = new BufferedReader(new FileReader(sdFile));
String str = "";
while ((str = br.readLine()) != null) {
String[] words = str.split(",");
// do some work
}
}
Log.d(LOG_TAG, str);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}

Android: Download from URL

i follow more explain in this site for download mp3 or picture from URL , I follow more method and try to write my method but when i run application it stop.
I make method to query download when click
also put permission for INTERNET & WRITE_EXTERNAL_STORAGE
put the problem is still
this method is download
public static void downloadMain(){
File fileToSave = null;
String scrPath ="http://***";
BufferedInputStream bis;
BufferedOutputStream bos;
fileToSave = new File(Environment.getExternalStorageDirectory().getPath() +"/"+ "A"+"/");
if (!fileToSave.exists())
fileToSave.mkdirs();
fileToSave = new File(Environment.getExternalStorageDirectory().getPath() +"/"+ "A" +"/" + "h"+"/");
if (!fileToSave.exists())
fileToSave.mkdirs();
File file = new File (fileToSave,"***.mp3");
try{
URL url = new URL(scrPath+"***.mp3");
URLConnection ucon = url.openConnection();
ucon.connect();
bis=new BufferedInputStream(ucon.getInputStream());
bos = new BufferedOutputStream(new FileOutputStream(file));
bis=new BufferedInputStream(url.openStream());
byte[] data = new byte[1024];
int a =0;
while(true){
int k = bis.read(data);
if(k==-1){
bis.close();
bos.flush();
bos.close();
break;
}
bos.write(data, 0, k);
a+=k;
}
}catch(IOException e){}
}

I have three main perplexity about your program:
Do you run the following code in an asynctask? (this must run asincronusly otherwise it will block)
Why it loop infinitly?
You couldn't open an url or a file named with a '*' inside of it
Edit:
You must run the download method asincronusly otherwise it wouldn't work, interaction with filesystem and network couldn't be done in the main thread
Edit2:
AsyncTask should be something like this
private class DownloadTask extends AsyncTask<String, Integer, String> {
private Context context;
public DownloadTask(Context context) {
this.context = context;
}
#Override
protected String doInBackground(String... sUrl) {
InputStream input = null;
OutputStream output = null;
HttpURLConnection connection = null;
try {
URL url = new URL(sUrl[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
// expect HTTP 200 OK, so we don't mistakenly save error report
// instead of the file
if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
return "Server returned HTTP " + connection.getResponseCode()
+ " " + connection.getResponseMessage();
}
// download the file
input = connection.getInputStream();
output = new FileOutputStream("/sdcard/file_name.extension");//put here your path and your mkdirs
byte data[] = new byte[4096];
long total = 0;
int count;
while ((count = input.read(data)) != -1) {
total += count;
output.write(data, 0, count);
}
} catch (Exception e) {
return e.toString();
} finally {
try {
if (output != null)
output.close();
if (input != null)
input.close();
} catch (IOException ignored) {
}
if (connection != null)
connection.disconnect();
}
return null;
}
#Override
protected void onPostExecute(String result) {
if (result != null)
Toast.makeText(context,"Download error: "+result, Toast.LENGTH_LONG).show();
else
Toast.makeText(context,"File downloaded", Toast.LENGTH_SHORT).show();
}
}
And you shoould call it like this
DownloadTask downloadTask = new DownloadTask(YourActivity.this);
downloadTask.execute("the url to the file you want to download");
You could also have a look at this answer

read file from another activity

I want to read a text file that i had write in another activity using OutputStreamWriter.
this is my readFromFile method in Sale.java:
private int readFromFile(String request) {
int res = 0;
try {
//InputStream inputStream = openFileInput("dalassnums.txt");
File file=new File("dalassnums.txt");
InputStream inputStream = new FileInputStream(file);
if ( inputStream != null ) {
InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
String receiveString = "";
while ( (receiveString = bufferedReader.readLine()) != null ) {
String s=bufferedReader.readLine();
if(receiveString==request) {
res=Integer.valueOf(s);
break;
}
}
inputStream.close();
}
}
catch (FileNotFoundException e) {
Log.e("login activity", "File not found: " + e.toString());
res=0;
} catch (IOException e) {
//Log.e("login activity", "Can not read file: " + e.toString());
}
return res;
}
And this is writeToFile method in MainActivity.java:
private void writeToFile2(String numchar) {
try {
//File file=new File("dalassnums.txt");
//OutputStream outputStream=new FileOutputStream(file);
OutputStreamWriter outputStreamWriter;
if(numchar=="1") outputStreamWriter = new OutputStreamWriter(openFileOutput("dalassnums.txt", Context.MODE_PRIVATE));
else outputStreamWriter = new OutputStreamWriter(openFileOutput("dalassnums.txt", Context.MODE_APPEND));
for(int k=0; k<imageNums.size();k+=2){
outputStreamWriter.append(imageNums.get(k));
outputStreamWriter.append("\n");
outputStreamWriter.append(imageNums.get(k+1));
outputStreamWriter.append("\n");
}
outputStreamWriter.close();
}
catch (IOException e) {
Log.e("Exception", "File write failed: " + e.toString());
}
}
When performing readFromFile, it returns 0 that means file not found;
I read about passing context but i don't know what context to pass; And wondering if there is any other way than passing context.
Any help would be appreciated.

Use : openFileInput in readFromFile, look here for example:
openFileInput() and/or openFileOutput() i/o streams silently failing
Another problem is that this is invalid:
if(numchar=="1")
you should
if(numchar.equals("1"))
otherwise you compare reference values instead content of string

Writing/Reading Files to/from Android phone's internal memory

I have an utility class named 'MyClass'. The class has two methods to read/write some data into phone's internal memory. I am new to android, Please follow below code.
public class MyClass {
public void ConfWrite() {
try {
BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(new
File(getFilesDir()+File.separator+"MyFile.txt")));
bufferedWriter.write("lalit poptani");
bufferedWriter.close();
} catch (Exception e1) {
e1.printStackTrace();
}
}
}
while executing ConfWrite method, it fails
please provide a better solution to solve this
thanks in advance

You can Read/ Write your File in data/data/package_name/files Folder by,
To Write
BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(new
File(getFilesDir()+File.separator+"MyFile.txt")));
bufferedWriter.write("lalit poptani");
bufferedWriter.close();
To Read
BufferedReader bufferedReader = new BufferedReader(new FileReader(new
File(getFilesDir()+File.separator+"MyFile.txt")));
String read;
StringBuilder builder = new StringBuilder("");
while((read = bufferedReader.readLine()) != null){
builder.append(read);
}
Log.d("Output", builder.toString());
bufferedReader.close();

public static void WriteFile(String strWrite) {
String strFileName = "Agilanbu.txt"; // file name
File myFile = new File("sdcard/Agilanbu"); // file path
if (!myFile.exists()) { // directory is exist or not
myFile.mkdirs(); // if not create new
Log.e("DataStoreSD 0 ", myFile.toString());
} else {
myFile = new File("sdcard/Agilanbu");
Log.e("DataStoreSD 1 ", myFile.toString());
}
try {
File Notefile = new File(myFile, strFileName);
FileWriter writer = new FileWriter(Notefile); // set file path & name to write
writer.append("\n" + strWrite + "\n"); // write string
writer.flush();
writer.close();
Log.e("DataStoreSD 2 ", myFile.toString());
} catch (IOException e) {
e.printStackTrace();
}
}
public static String readfile(File myFile, String strFileName) {
String line = null;
try {
FileInputStream fileInputStream = new FileInputStream(new File(myFile + "/" + strFileName)); // set file path & name to read
InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream); // create input steam reader
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
StringBuilder stringBuilder = new StringBuilder();
while ((line = bufferedReader.readLine()) != null) { // read line by line
stringBuilder.append(line + System.getProperty("line.separator")); // append the readed text line by line
}
fileInputStream.close();
line = stringBuilder.toString(); // finially the whole date into an single string
bufferedReader.close();
Log.e("DataStoreSD 3.1 ", line);
} catch (FileNotFoundException ex) {
Log.e("DataStoreSD 3.2 ", ex.getMessage());
} catch (IOException ex) {
Log.e("DataStoreSD 3.3 ", ex.getMessage());
}
return line;
}
use this code to write --- WriteFile(json); // json is a string type
use this code to read --- File myFile = new File("sdcard/Agilanbu");
String strObj = readfile(myFile, "Agilanbu.txt");
// you can put it in seperate class and just call it where ever you need.(for that only its in static)
// happie coding :)