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 :)
Related
I want to use a Class method to read a text file & pass a return value.
My error is the line:
fis = openFileInput(FILE_NAME);
The error message is:
Cannot resolve method 'openFileInput(java.lang.String)'
I suspect it's because I'm not passing a context, or that Android does not know the full file path using my Class method code.
I want to use the Class method so I can call it from various Activities.
import java.io.FileInputStream;
public static String GetUserId(){
String str_return = null;
String FILE_NAME = "userid.txt";
try {
FileInputStream fis = null;
fis = openFileInput(FILE_NAME); \\<-- error is here
InputStreamReader isr = new InputStreamReader(fis);
BufferedReader br = new BufferedReader(isr);
StringBuilder sb = new StringBuilder();
String text;
while ((text = br.readLine()) != null) {
sb.append(text).append("\n");
}
} catch (FileNotFoundException e) {
//e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (fis != null) {
try {
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
try this :
File yourFile = new File("YOUR_TEXTFILE_PATH");
String data = null;
try (FileInputStream stream = new FileInputStream(yourFile)) {
FileChannel fc = stream.getChannel();
MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
data = Charset.defaultCharset().decode(bb).toString(); //this is the data from your textfile
} catch (Exception e) {
e.printStackTrace();
}
And generating the textfile
File root = new File("YOUR_FOLDER_PATH");
//File root = new File(Environment.getExternalStorageDirectory(), folderName); //im using this
//creation of folder (if you want)
if (!root.exists()) {
root.mkdirs();
}
File gpxfile = new File(root, textFileName);
FileWriter writer;
writer = new FileWriter(gpxfile);
writer.append(textFileData);
writer.flush();
writer.close();
}
I have done it in one of my kotlin project likethis, It might work in Java too.
val textFromFile = openFileInput(filePath).reader().readText()
I want to save my data in a .txt file. In another activity I want to be able to read the saved data. I want to save multible values each time and put them together on a line, the next values need to be in a new line. I tried \n System.getProperty("line.separator"); System.lineSeparator(); and \n\r to start in a new line but this doesn't seem to work while the data still end up behind each other instead of being on another line.
I use this code to write to the file:
Context context = getApplicationContext();
writedatatofile(context);
protected void writedatatofile(Context context){
try
{
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(context.openFileOutput("data_log.txt", Context.MODE_APPEND));
String data;
if (newstart){
data = "Exersice started \n" + "t.s a.s t.a a.a cnst";
} else {
data = (Integer.toString(time_step)+Integer.toString(new_average_step)+Integer.toString(time_footaid)+Integer.toString(new_average_aid)+Boolean.toString(rhythmconsistent)+"\n");
}
outputStreamWriter.append(data);
outputStreamWriter.close();
Toast.makeText(this, "Data has been written to File", Toast.LENGTH_SHORT).show();
}
catch(IOException e) {
e.printStackTrace();
}
}
and this code to read the file:
Context context = getApplicationContext();
String fileData = readFromFile(context, fileName);
TextView datalog = findViewById(R.id.datalog);
datalog.setText(fileData);
private String readFromFile(Context context, String fileName){
String ret = " ";
try {
InputStream inputStream = context.openFileInput(fileName);
if (inputStream != null) {
InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
String receiveString = "";
StringBuilder stringBuilder = new StringBuilder();
while ((receiveString = bufferedReader.readLine()) != null) {
Toast.makeText(this, "Data received", Toast.LENGTH_SHORT).show();
stringBuilder.append(receiveString);
}
inputStream.close();
ret = stringBuilder.toString();
} else {
Toast.makeText(this, "No data received", Toast.LENGTH_SHORT).show();
}
} catch (FileNotFoundException e){
Toast.makeText(this, "File not found", Toast.LENGTH_SHORT).show();
} catch (IOException e){
Toast.makeText(this, "Can not read file", Toast.LENGTH_SHORT).show();
}
return ret;
}
As mentioned "\n" doesn't solve the problem but is also doesn't show up in my dataas \n. So it is not stored as a normal String.
When you write the file:
BufferedWriter writer = new BufferedWriter(outputStreamWriter);
writer.write(data);
writer.newLine(); // <-- this is the magic
writer.close();
You can read the data from .txt file using below code.
File exportDir = new File(Environment.getExternalStorageDirectory(), File.separator + "bluetooth/abc.txt");
if (exportDir.exists()) {
FileReader file = null;
try {
file = new FileReader(exportDir);
BufferedReader buffer = new BufferedReader(file);
String line = "";
int iteration = 0;
while ((line = buffer.readLine()) != null) { //read next line
if (iteration == 0) { //Skip the 1st position(header)
iteration++;
continue;
}
StringBuilder sb = new StringBuilder();
String[] str = line.split(",");
//get the single data from column
String text1 = str[1].replace("\"", "");
String text2 = str[2].replace("\"", "");
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
I tried using many codes I've found for downloading files with an AsyncTask with no success yet.
I get an error on the logcat: E/Error:: No such file or directory.
Despite looking for solutions for this error, couldn't find What's missing or wrong.
This is the doInBackground method in which I assume something is missing/wrong:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash);
new DownloadJSON().execute("http://api.androidhive.info/json/movies.json");
}
protected String doInBackground(String...fileUrl) {
int count;
try {
String root = "data/data/com.example.jsonapp2";
URL url = new URL(fileUrl[0]);
URLConnection connection = url.openConnection();
connection.connect();
// input stream to read file - with 8k buffer
InputStream input = new BufferedInputStream(url.openStream(), 8192);
File fileName = new File(root+"/movies.json");
boolean existsOrNot = fileName.createNewFile(); // if file already exists will do nothing
// Output stream to write file
OutputStream output = new FileOutputStream(fileName,false);
byte data[] = new byte[1024];
System.out.println("Downloading");
long total = 0;
while ((count = input.read(data)) != -1) {
total += count;
// 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;
}
Thanks.
Didn't want to bombard with redundant code. If some other code is needed, I'd love to provide it.
UPDATED ANSWER
this is working for me, write file in local storage and read it again on method PostExecute
class DownloadJSON extends AsyncTask<String, Void, Void>{
String fileName;
String responseTxt;
String inputLine;
String folder;
#Override
protected Void doInBackground(String... strings) {
try {
String root = "data/data/com.example.jsonapp2";
URL url = new URL(strings[0]);
HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection();
//Set methods and timeouts
urlConnection.setRequestMethod("GET");
urlConnection.setReadTimeout(15000);
urlConnection.setConnectTimeout(15000);
urlConnection.connect();
//Create a new InputStreamReader
InputStreamReader streamReader = new
InputStreamReader(urlConnection.getInputStream());
BufferedReader reader = new BufferedReader(streamReader);
StringBuilder response = new StringBuilder();
//Check if the line we are reading is not null
while((inputLine = reader.readLine()) != null){
response.append(inputLine);
}
//Close our InputStream and Buffered reader
reader.close();
streamReader.close();
responseTxt = response.toString();
Log.d(TAG, "doInBackground: responseText " + responseTxt);
// PREPARE FOR WRITE FILE TO DEVICE DIRECTORY
FileOutputStream fos = null;
fileName = "fileName.json";
folder = fileFolderDirectory();
try {
fos = new FileOutputStream(new File(folder + fileName));
//fos = openFileOutput(folder + fileName, MODE_PRIVATE);
fos.write(responseTxt.getBytes());
} catch (IOException e) {
e.printStackTrace();
} finally {
if(fos != null){
fos.close();
}
}
} catch (Exception e) {
Log.e("Error: ", e.getMessage());
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
// -- THIS METHOD IS USED TO ENSURE YOUR FILE AVAILABLE INSIDE LOCAL DIRECTORY -- //
FileInputStream fis = null;
try {
fis = new FileInputStream(new File(folder +fileName));
InputStreamReader isr = new InputStreamReader(fis);
BufferedReader br = new BufferedReader(isr);
StringBuilder sb = new StringBuilder();
String text;
while ((text = br.readLine()) != null) {
sb.append(text).append("\n");
}
Toast.makeText(TestActivity.this, "result " + sb.toString(), Toast.LENGTH_SHORT).show();
} catch (IOException e) {
e.printStackTrace();
}finally {
try {
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
ops, almost forget this method
public static String fileFolderDirectory() {
String folder = Environment.getExternalStorageDirectory() + File.separator + "write_your_app_name" + File.separator;
File directory = new File(folder);
if(!directory.exists()){
directory.mkdirs();
}
return folder;
}
Your root is wrong
String root = "data/data/package.appname";
make sure your root contains right package name or file path.
package name which should be your application id
I want to read XML file, save it as String and pass to setText. I don't want to parse it but see it on my smartphone screen with all tags and white-characters, eg.
<a>
<b>some text</b>
</a>
not:
some text
How to do it?
FYI, this is how I solve my problem:
public String readXML() {
String line;
StringBuilder total = new StringBuilder();
try {
InputStream is = activity.getAssets().open("subjects.xml");
BufferedReader r = new BufferedReader(new InputStreamReader(is, "UTF-8"));
total = new StringBuilder();
while ((line = r.readLine()) != null) {
total.append(line + "\n");
}
} catch (IOException e) {
e.printStackTrace();
}
return total.toString();
}
Use FileInputStream to read file:
File file = new File(<FilePath>);
if (!file.exists()) {
System.out.println("File does not exist.");
return;
}
if (!(file.isFile() && file.canRead())) {
System.out.println(file.getName() + " cannot be read from.");
return;
}
try {
FileInputStream stream = new FileInputStream(file);
char current;
while (stream.available() > 0) {
current = (char) stream.read();
//Do something with character
}
} catch (IOException e) {
e.printStackTrace();
}
What I am trying to accomplish is to read a file line by line and store each line into an ArrayList. This should be such a simple task but I keep running into numerous problems. At first, it was repeating the lines when it was saved back into a file. Another error which seems to occur quite often is that it skips the try but doesn't catch the exception? I have tried several techniques but no luck. If you have any advice or could provide help in anyway it would be greatly appreciated. Thank you
Current code:
try{
// command line parameter
FileInputStream fstream = new FileInputStream(file);
// Get the object of DataInputStream
DataInputStream in = new DataInputStream(fstream);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String strLine;
while ((strLine = br.readLine()) != null) {
fileList.add(strLine);
}
//Close the input stream
in.close();
} catch (Exception e){//Catch exception if any
Toast.makeText(this, "Could Not Open File", Toast.LENGTH_SHORT).show();
}
fileList.add(theContent);
//now to save back to the file
try {
FileWriter writer = new FileWriter(file);
for(String str: fileList) {
writer.write(str);
writer.write("\r\n");
}
writer.close();
} catch (java.io.IOException error) {
//do something if an IOException occurs.
Toast.makeText(this, "Cannot Save Back To A File", Toast.LENGTH_LONG).show();
}
There is a very simple alternative to what you are doing with Scanner class:
Scanner s = new Scanner(new File("filepath"));
ArrayList<String> list = new ArrayList<String>();
while (s.hasNext()){
list.add(s.next());
}
s.close();
Why do you have fileList.add(theContent) after the try/catch? I don't see what the point of that is. Remove that line and see if it helps.
Example, I just tested this code on my local machine (not android but should be the same)
import java.io.*;
import java.util.ArrayList;
class FileRead
{
public static void main(String args[])
{
ArrayList<String> fileList = new ArrayList<String>();
final String file = "textfile.txt";
final String outFile = "textFile1.txt";
try{
FileInputStream fstream = new FileInputStream(file);
DataInputStream in = new DataInputStream(fstream);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String strLine;
//Read File Line By Line
while ((strLine = br.readLine()) != null) {
// Print the content on the console
fileList.add(strLine);
}
//Close the input stream
in.close();
} catch (Exception e){//Catch exception if any
System.err.println("Error: " + e.getMessage());
}
try {
FileWriter writer = new FileWriter(outFile);
for(String str: fileList) {
writer.write(str);
writer.write("\r\n");
}
writer.close();
} catch (java.io.IOException error) {
System.err.println("Error: " + error.getMessage());
}
}
}
After I ran this the 2 files had no differences. So my guess is that line may have something to do with it.