I would like to store my string values as a text file and hence i declared like
String item1, item2;
//code...
item1=arraylist.getItem1();
item2=arraylist.getItem2();
FileOutputStream fos;
try {
fos = openFileOutput(item1, Context.MODE_PRIVATE);
fos.write(item2.getBytes());
fos.close();
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
//code....
But am getting an error of
1)java.lang.illegalargumentexception file contains a path separator
and my textfile in data/data/my package dir couldn't be opened and displays a message of
opendir failed permission denied android adb
What am doing wrong here and how can i store and see the values of my string in a text file.
1) java.lang.illegalargumentexception file contains a path separator
openFileOutput() doesn't accept paths, only a file name. If you want to create a file using a path try:
BufferedWriter writer;
try {
File file = new File(filePath);
FileWriter fileWriter = new FileWriter(file);
writer = new BufferedWriter(fileWriter);
...
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
2) opendir failed permission denied android adb
In android you cannot access files in in your phone. If you need to access the file then you need to save it somewhere accessible such as SD card.
Finally i resolved this issue. I created a new class and instantiated this class in the previous class and my codings are:
public void Class1(String item1, String item2, Context context)
{
FileOutputStream fos;
try {
fos = context.openFileOutput("newfile.txt", Context.MODE_PRIVATE);
fos.write(item1.getBytes());
fos.write(item2.getBytes());
fos.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
and i instantiated this class as
Class1 main = new Class1();
tracklog.Logger(item1, item2,this);
Hence illegal argument exception error got resolved. Hope this may help someone :-)
Related
Honestly, I've searched a lot do this task so I ended up trying various methods but nothing worked until I ended up on this code. It works for me perfectly like it should, so I do not want to change my code.
The help I need is to put this code in a such a way that it begins to read a file, but if it the file doesn't exist then it will create a new file.
Code for saving data:
String data = sharedData.getText().toString();
try {
fos = openFileOutput(FILENAME, MODE_PRIVATE);
fos.write(data.getBytes());
fos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Code for loading data:
FileInputStream fis = null;
String collected = null;
try {
fis = openFileInput(FILENAME);
byte[] dataArray = new byte [fis.available()];
while (fis.read(dataArray) != -1){
collected = new String(dataArray);
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
try {
fis.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
So If I add the saving data code in to the "FileNotFoundException" catch of the loading data part then could I achieve what I want?
Add
File file = new File(FILENAME);
if(!file.exists())
{
file.createNewFile()
// write code for saving data to the file
}
above
fis = openFileInput(FILENAME);
This will check if there exists a File for the given FILENAME and if it doesn't it will create a new one.
If you're working on Android, why don't you use the API's solution for saving files?
Quoting:
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();
}
You should really read the whole document, they explain pretty well the basic ways of creating or accessing files, you can also check the different ways of storing data.
But regarding your original question:
So If I add the saving data code in to the "FileNotFoundException"
catch of the loading data part then could I achieve what I want?
Yes, you could achieve it.
Try this one:
public static void readData() throws IOException
{
File file = new File(path, filename);
if (!file.isFile() && !file.createNewFile()){
throw new IOException("Error creating new file: " + file.getAbsolutePath());
}
BufferedReader r = new BufferedReader(new FileReader(file));
try {
// ...
// read data
// ...
}finally{
r.close();
}
}
Ref: Java read a file, if it doesn't exist create it
So many examples for this question. I tried and still doesn't work.
Test.txt file is created. But no data is written into the test.txt file.
What is wrong with my code? I have permission in the Manifest file as
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
Code:
String file_path = Environment.getExternalStorageDirectory().getAbsolutePath() +
"/PrintFiles";
File file = new File(file_path+"/test.txt");
if (!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
FileOutputStream fos = null;
try {
fos = openFileOutput(file.getName(), Context.MODE_PRIVATE);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
byte[] b = {65,66,67,68,69};
fos.write(b);
fos.flush();
fos.close();
Cause, you are creating file in SDCard but writing in Internal Storage. Try as follows...
String file_path = Environment.getExternalStorageDirectory().getAbsolutePath() +
"/PrintFiles";
File file = new File(file_path+"/test.txt");
if (!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
FileOutputStream fos = null;
try {
fos = new FileOutputStream(file);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
byte[] b = {65,66,67,68,69};
fos.write(b);
fos.flush();
fos.close();
From the doc openFileOutput will
Open a private file associated with this Context's application package for writing. Creates the file if it doesn't already exist.
those files are under the.
data > data > your app id > files
but your file is not in internal folder its in external storage..
Change this line
fos = openFileOutput(file.getName(), Context.MODE_PRIVATE);
into
fos=new FileOutputStream(file);
And try..
i have problem with file writing. I want to create OnClick method of button that add line to file on sdcard but instead it delete previous line and put all content in place of current one. In result i got only the Text i put at the last click of Button, here is my code:
if (txtFile.createNewFile() || txtFile.isFile()) {
FileOutputStream fOut = null;
try {
fOut = new FileOutputStream(txtFile);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
OutputStreamWriter myOutWriter = new OutputStreamWriter(fOut);
BufferedWriter bwriter = new BufferedWriter(myOutWriter);
EditText desc__ = (EditText)findViewById(R.id.descriptionEditTExt);
try {
bwriter.newLine();
bwriter.write(lat+"|"+lng+"|"+desc__.getText().toString()+"|"+f+"|"+position);
bwriter.close();
myOutWriter.close();
fOut.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} else {
/* handle directory here */
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Please rewrite your FileOutputStream constructor as
FileOutputStream fos = new FileOutputStream(file, true);
here is suggests that your file will be opened in the append mode which will solve your first problem..
secondly if you want to add new line to the file use "\r\n" string
e.g. fos.write("\r\n".getBytes());
Hope this helps..
I am able to write and then read a text file in the SAME activity, but I am unable to read a text file after writing to it from another Activity.
Ex: Activity A creates and writes to a text file. Activity B reads that text file.
I use this code to write to the text file in Activity A:
FileOutputStream fos = null;
OutputStreamWriter osw = null;
try
{
fos = openFileOutput("user_info.txt", Context.MODE_WORLD_WRITEABLE);
osw = new OutputStreamWriter(fos);
osw.write("text here");
osw.close();
fos.close();
}
catch (FileNotFoundException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
And then I use this code to try and read the same text file created by Activity A, but I get a FileNotFoundException:
try
{
FileInputStream fis = openFileInput("user_info.txt");
InputStreamReader isr = new InputStreamReader(fis);
BufferedReader buff = new BufferedReader(isr);
String line;
while((line = buff.readLine()) != null)
{
Toast.makeText(this, line, Toast.LENGTH_LONG).show();
}
}
catch (FileNotFoundException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
Does anyone know why I am getting the FileNotFoundException?
Is it a path issue?
Don't really know how is built your application, but, the error you get does seem like a path issue, are you sure both Activities are in the same folder ?
If not, you'll need to set either an abolute path (like : "/home/user/text.txt") for the text file or a relative path (like : "../text.txt").
If you're not sure, try to print the current path for the Activity using some command like
new File(".").getAbsolutePath();
And, although I can't say I'm expert with Android, are you sure you need the Context.MODE_WORLD_WRITEABLE for your file ? If no other application than yours is reading or writing from/to it, it should not be necessary, right ?
it is surealy a path issue.
you can write like this
fpath=Environment.getExternalStorageDirectory().getAbsolutePath()+"/"+"yourdirectory";
File custdir=new File(fpath);
if(!custdir.exists())
{
custdir.mkdirs();
}
File savedir=new File(custdir.getAbsolutePath());
File file = new File(savedir, filename);
if(file.exists())
{
file.delete();
}
FileOutputStream fos;
byte[] data = texttosave.getBytes();
try {
fos = new FileOutputStream(file);
fos.write(data);
fos.flush();
fos.close();
Toast.makeText(getBaseContext(), "File Saved", Toast.LENGTH_LONG).show();
finish();
} catch (FileNotFoundException e) {
Toast.makeText(getBaseContext(), "Error File Not Found", Toast.LENGTH_LONG).show();
Log.e("fnf", ""+e.getMessage());
// handle exception
} catch (IOException e) {
// handle exception
Toast.makeText(getBaseContext(), "Error IO Exception", Toast.LENGTH_LONG).show();
}
and you can read like
String locatefile=Environment.getExternalStorageDirectory().getAbsolutePath()+"/"+"yourdirectory"+"/filename";
try {
br=new BufferedReader(new FileReader(locatefile));
while((text=br.readLine())!=null)
{
body.append(text);
body.append("\n");
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
I need to write entire Logcat in to sdcard not the filtered Logcat. So I tried doing this way
String[] cmd ={"/system/bin/logcat " +"-f"+" /sdcard/d.txt"};
Log.d("NTK","cmd string"+cmd);
Runtime run = Runtime.getRuntime();
Process pr;
try {
pr = run.exec(cmd);
pr.waitFor();
BufferedReader buf = new BufferedReader(new InputStreamReader(pr.getInputStream()));
String line = "";
while ((line=buf.readLine())!=null) {
System.out.println(line);
Log.i(NTL, "lines"+line);
}
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
I have given all permissions in manifest file too.
Not able to write logcat in to sdcard.
You can have this Tutorial for Reading the Logs. And for writing the logs in the file you can simply use FileWriter give path of the file with file name.
try {
File root = Environment.getExternalStorageDirectory();
if (root.canWrite()) {
File gpslogfile = new File(root, "log.txt");
FileWriter gpswriter = new FileWriter(gpslogfile, true);
BufferedWriter out = new BufferedWriter(gpswriter);
out.append(DataToWrite);
out.close();
}
} catch (IOException e) {
Log.d("Log: ", "Could not write file " + e.getMessage());
}