Develop Reference

Retrieve the saved WiFi passwords from Android devices

I am developing an Android application in which I need to show the saved WiFi passwords in the mobile or tablet. Like for example, if my mobile is connected to any network that n/w password is saved in my mobile. I want to get it.

Unless you are rooted, I don't know of any way to do it. If you are rooted, or are willing to root your Galaxy for those nice guy points, you should be able to use a file manager (ASTRO, Root Browser, etc.) to find it.
Use the file manager to locate your data/misc/file folder, then look for wpa_supplicant.conf, or I assume it could be wep_supplicant.conf if his/her network is using WEP instead of WPA. Open the .conf file using a text editor (which is probably built into your file manager application, if not, add that to your shopping list). You should be able to read the password in plain text at that point.

Your Comments helped me to some extent to find out the solution to my question. Especially #Namik Kalavadia I am talking about you Thanks for that.
Finally here is the solution.
public class MainActivity extends Activity {
File file;
public StringBuffer ab;
public File savefile;
public InputStream in = null;
public String filename = "wpa_supplicant.conf";
public File ot_path;
Context context;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
context = getApplicationContext();
ot_path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
Log.d("aaa", ""+ot_path.toString());
}
public void path(View v){
getPath();
}
private void getPath(){
file = Environment.getRootDirectory();
String ext = ".conf";
File list[] = file.listFiles();
ab = new StringBuffer();
if(list!=null){
fileNameSearch(list);
}
}
public void fileNameSearch(File list[]){
if(list!=null){
for(int f = 0;f<list.length;f++){
ab.append(list[f].getName()+"\n");
File fi = list[f];
String path = fi.getPath();
if(fi.isDirectory()){
fileNameSearch(fi.listFiles());
}
else if(path.endsWith(".conf")){
if(path.contains(filename)){
try{
File fileForParse = copyFile(path,ot_path);
in = new FileInputStream(fileForParse);
getStringFromInputStream(in);
Log.d("aaa", "conf I got it"+path);
}catch(Exception e){
e.printStackTrace();
}
}
}
}
}
else{
Log.d("aaa", "List is null in method");
}
}
private File copyFile(String inputPath, File outputPath) {
InputStream input = null;
OutputStream out = null;
try {
if (!outputPath.exists())
{
outputPath.mkdirs();
}
savefile = new File(outputPath,filename);
if (!savefile.exists()) {
savefile.createNewFile();
File f = new File(inputPath);
Log.d("aaa",""+f.length());
input = new FileInputStream(inputPath);
out = new FileOutputStream(savefile);
byte[] buffer = new byte[1024];
int read;
while ((read = input.read(buffer)) != -1) {
out.write(buffer, 0, read);
}
Log.d("aaa",""+savefile.length());
input.close();
input = null;
out.flush();
out.close();
out = null;
}
} catch (FileNotFoundException fnfe1) {
Log.e("aaa", fnfe1.getMessage());
return null;
}
catch (Exception e) {
Log.e("aaa", e.getMessage());
return null;
}
return savefile;
}
#SuppressWarnings("deprecation")
private String getStringFromInputStream(InputStream is) {
BufferedReader br = null;
StringBuilder sb = new StringBuilder();
String line;
try {
br = new BufferedReader(new InputStreamReader(is));
while ((line = br.readLine()) != null) {
if(line.contains("ssid")||line.contains("psk")){
sb.append(line+"\n");
}
if(line.contains("}")){
sb.append("-----------------\n");
}
AlertDialog ad = new AlertDialog.Builder(MainActivity.this).create();
ad.setTitle("Lis of WiFi Passwords Saved in your Mobile");
ad.setMessage(sb);
ad.setButton("OK",new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
finish();
}
});
ad.show();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (br != null) {
try {
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return sb.toString();
}
}

It is not possible as far as I know . It will be a security problem if sdk tools allows to do so .

Retrieving saved Wifi password programatically is not possible due to security issue.If you root your phone you may able to get it,but that too in an encrypted form.

Android where file is saved FileOutputStream

Here how I write bytes to a file. I'm using FileOutputStream
private final Handler handler = new Handler(){
#Override
public void handleMessage(Message msg) {
FragmentActivity activity = getActivity();
byte[] readBuffer = (byte[]) msg.obj;
FileOutputStream out = null;
try {
out = new FileOutputStream("myFile.xml");
out.write(readBuffer);
out.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
and now I want to open that file, so I need to have path of that file. So how I need to open that file?
EDIT:
Here how I read from file, but I can't see anything...
BufferedReader reader = null;
FileInputStream s = null;
try {
s = new FileInputStream("mano.xml");
reader = new BufferedReader(new InputStreamReader(s));
String line = reader.readLine();
Log.d(getTag(), line);
while (line != null) {
Log.d(getTag(), line);
line = reader.readLine();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}

I recommend to use this for writting:
OutputStream out = new FileOutputStream(Environment.getExternalStorageDirectory().getAbsolutePath()+"/yourfilename");
So to read the location:
File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath()+"/"+transaction.getUniqueId()+".pdf");
To read the path:
file.getAbsolutePath();

Your file is save in path /Data/Data/Your package Name/files/myFile.xml
you can use this.getFileDir() method to get the path of the files folder on the Application.
So use this.getFileDir() + "myFile.xml" to read the file.

How it is reported inside the developers guide you have to specify where you want to save your file. You can choose between:
Saving the file in the internal storage:
String filename = "myfile";
String string = "Hello world!";
FileOutputStream outputStream;
try {
outputStream = openFileOutput(filename, Context.MODE_PRIVATE);
outputStream.write(string.getBytes());
outputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
Or on second instance you could save your file in external storage:
// Checks if external storage is available to at least read
public boolean isExternalStorageReadable() {
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state) || Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
return true;
}
return false;
}
Just remember to set permissions!!!!
Here there is the entire documentation: Documentation

Error in adding text to existing txt file

Firstly, i know there are same questions in this web site but i couldn't add text to my existing txt file. maybe i miss out something but where ? anyway here are my codes.
i have translate.txt file. it is /raw folder.and When i click the button, the words which are written in the editTexts(w1,w2) must be added to the existing translate.txt file.But it is not working..
public class Add extends Activity {
EditText w1,w2;
Button save;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.add);
w1=(EditText)findViewById(R.id.idText1);
w2=(EditText)findViewById(R.id.idText2);
save=(Button) findViewById(R.id.idSave);
save.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
String word1=w1.getText().toString();
String word2=w2.getText().toString();
writefile(word1,word2);
}
});
}
public void writefile(String word1,String word2)
{
try
{
String finalstring=new String(word1 + " " + word2);
FileOutputStream fOut = openFileOutput("translate.txt",MODE_APPEND);
OutputStreamWriter osw = new OutputStreamWriter(fOut);
osw.write(finalstring);
osw.flush();
osw.close();
Toast.makeText(this, "Saved", Toast.LENGTH_SHORT).show();
} catch(Exception e)
{
Toast.makeText(this, "ERROR!!!", Toast.LENGTH_SHORT).show();
}
}
}

A) Code to write APPEND file in Android
public void writefile(String word1,String word2)
try {
String path = sdCard.getAbsolutePath() + "/";
File logFile = new File(path + "translate.txt");
if (!logFile.exists()) {
logFile.createNewFile();
}
// BufferedWriter for performance, true to set append to file
FileWriter fw = new FileWriter(logFile, true);
BufferedWriter buf = new BufferedWriter(fw);
buf.append(word1 + " " + word2);
buf.newLine();
buf.flush();
}
buf.close();
} catch (IOException e) {
e.printStackTrace();
}
B) Rule/ Permission
AndroidManifest.xml
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
EDIT For user
You cannot write a file to raw folder. Its read-only. Precisely you can't modify anything contained within "Res" folder on the fly.
Check this out, https://stackoverflow.com/a/3374149

Just in case you don't want to store the data in sd card and want to use the previous method
the way you was creating a file and stroing data to it was not actually editing the file in res/ raw folder ( because it can not be edited )
but the data you was writing was actually stored in a private file associated with this Context's application package for reading.
hence it was there and the file can be read as follow:
private void readFile() {
// TODO Auto-generated method stub
try {
FileInputStream fin = openFileInput("translate.txt");
InputStreamReader isr = new InputStreamReader(fin);
BufferedReader br = new BufferedReader(isr);
String str;
StringBuilder str2 = new StringBuilder();
while ((str = br.readLine()) != null) {
str2 = str2.append(str);
}
isr.close();
editText.setText(str2.toString());
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
you can follow this method incase you dont want to store file in sd card because files in sd crad can be read by anyone.

I can create file but can't write to it

Could someone look at this snippet of code please and let me know what I'm doing wrong? It's a simple function that takes a string as parameter which it uses as a file name, adding ".txt" to the end of it.
The function checks if the file exists, creating it if it doesn't and then writes two lines of text to the file. Everything appears to be working and the file is created successfully on the sd card. However, after everything is done, the file is empty (and has a size of 0 bytes).
I suspect it's something obvious that I'm overlooking.
public void writeFile(String fileName) {
String myPath = new File(Environment.getExternalStorageDirectory(), "SubFolderName");
myPath.mkdirs();
File file = new File(myPath, fileName+".txt");
try {
if (!file.exists()) {
if (!file.createNewFile()) {
Toast.makeText(this, "Error Creating File", Toast.LENGTH_LONG).show();
return;
}
}
OutputStreamWriter writer = new OutputStreamWriter(openFileOutput(file.getName(), Context.MODE_PRIVATE));
writer.append("First line").append('\n');
writer.append("Second line").append('\n');
writer.close();
}
catch (IOException e) {
// Do whatever
}
}

Hi I will show you the full code I use, works perfect.
I don't use
new OutputStreamWriter()
i use
new BufferedWriter()
here is my Snippet
public void writeToFile(Context context, String fileName, String data) {
Writer mwriter;
File root = Environment.getExternalStorageDirectory();
File dir = new File(root.getAbsolutePath() + File.separator + "myFolder");
if (!dir.isDirectory()) {
dir.mkdir();
}
try {
if (!dir.isDirectory()) {
throw new IOException(
"Unable to create directory myFolder. SD card mounted?");
}
File outputFile = new File(dir, fileName);
mwriter = new BufferedWriter(new FileWriter(outputFile));
mwriter.write(data); // DATA WRITE TO FILE
Toast.makeText(context.getApplicationContext(),
"successfully saved to: " + outputFile.getAbsolutePath(), Toast.LENGTH_LONG).show();
mwriter.close();
} catch (IOException e) {
Log.w("write log", e.getMessage(), e);
Toast.makeText(context, e.getMessage() + " Unable to write to external storage.",Toast.LENGTH_LONG).show();
}
}
-- Original Code --

That one took a while to find out. The javadocs
here brought me on the right track.
It says:
Parameters
name The name of the file to open; can not contain path separators.
mode Operating mode. Use 0 or MODE_PRIVATE for the default operation, MODE_APPEND to append to an existing file, MODE_WORLD_READABLE and MODE_WORLD_WRITEABLE to control permissions.
The file is created, if it does not exist, but it is created in the private app space. You create the file somewhere on the sd card using File.createNewFile() but when you do context.openFileOutput() it creates always a private file in the private App space.
EDIT: Here's my code. I've expanded your method by writing and reading the lines and print what I got to logcat.
<pre>
public void writeFile(String fileName) {
try {
OutputStreamWriter writer = new OutputStreamWriter(
getContext().openFileOutput(fileName + ".txt", Context.MODE_PRIVATE));
writer.append("First line").append('\n');
writer.append("Second line").append('\n');
writer.close();
}
catch (IOException e) {
Log.e("STACKOVERFLOW", e.getMessage(), e);
return;
// Do whatever
}
// Now read the file
try {
BufferedReader is = new BufferedReader(
new InputStreamReader(
getContext().openFileInput(fileName + ".txt")));
for(String line = is.readLine(); line != null; line = is.readLine())
Log.d("STACKOVERFLOW", line);
is.close();
} catch (IOException e) {
Log.e("STACKOVERFLOW", e.getMessage(), e);
return;
// Do whatever
}
}

Change the mode from Context.MODE_PRIVATE to Context.MODE_APPEND in openFileOutput()
MODE_APPEND
MODE_PRIVATE
Instead of
OutputStreamWriter writer = new OutputStreamWriter(openFileOutput(file.getName(), Context.MODE_PRIVATE));
Use
OutputStreamWriter writer = new OutputStreamWriter(openFileOutput(file.getName(), Context.MODE_APPEND));
UPDATE :
1.
FileOutputStream osr = new FileOutputStream(file.getName(), true); // this will set append flag to true
OutputStreamWriter writer = new OutputStreamWriter(osr);
BufferedWriter fbw = new BufferedWriter(writer);
fbw.write("First line");
fbw.newLine();
fbw.write("Second line");
fbw.newLine();
fbw.close();
Or 2.
private void writeFileToInternalStorage() {
FileOutputStream osr = new FileOutputStream(file.getName(), true); // this will set append flag to true
String eol = System.getProperty("line.separator");
BufferedWriter fbw = null;
try {
OutputStreamWriter writer = new OutputStreamWriter(osr);
fbw = new BufferedWriter(writer);
fbw.write("First line" + eol);
fbw.write("Second line" + eol);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (fbw != null) {
try {
fbw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}

Writing to text file in "APPEND mode" in emulator-mode,

In my Android app I should store the data from user in simple text-file, that I created in the raw directory. After this, I'm trying to write file in APPEND MODE by using simple code from the Google's examples:
try
{
FileOutputStream fos = openFileOutput(FILE_NAME, Context.MODE_APPEND);
fos.write((nameArticle+"|"+indexArticle).getBytes());
fos.close();
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
But nothing happens: no exceptions, but I can see nothing in my FILE_NAME, besides the single record, which was added by me.
What am I doing wrong ? Is it possible at common to write to file in emulator ?

openFileOutput will only allow you to open a private file associated with this Context's application package for writing. I'm not sure where the file you're trying to write to is located. I mean full path. You can use the code below to write to a file located anywhere (as long as you have perms). The example is using the external storage, but you should be able to modify it to write anywhere:
public Uri writeToExternalStoragePublic() {
final String filename = mToolbar.GetTitle() + ".html";
final String packageName = this.getPackageName();
final String folderpath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/Android/data/" + packageName + "/files/";
File folder = new File(folderpath);
File file = null;
FileOutputStream fOut = null;
try {
try {
if (folder != null) {
boolean exists = folder.exists();
if (!exists)
folder.mkdirs();
file = new File(folder.toString(), filename);
if (file != null) {
fOut = new FileOutputStream(file, false);
if (fOut != null) {
fOut.write(mCurrentReportHtml.getBytes());
}
}
}
} catch (IOException e) {
Toast.makeText(this, e.getMessage(), Toast.LENGTH_LONG).show();
}
return Uri.fromFile(file);
} finally {
if (fOut != null) {
try {
fOut.flush();
fOut.close();
} catch (IOException e) {
Toast.makeText(this, e.getMessage(), Toast.LENGTH_LONG).show();
}
}
}
}
In the example you have given, try catching 'I0Exception`, I have a feeling you do not have permission where you are trying to write.
Have a Happy New Year.