Hey I would like to save datas and then I would like to read them and put them in a EditText
speichern.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
save();
tv.setText("gespeichert");
}
});
private void save() {
try {
File myFile = new File("bla.txt");
myFile.createNewFile();
FileOutputStream fOut = new FileOutputStream(myFile);
OutputStreamWriter myOutWriter =
new OutputStreamWriter(fOut);
myOutWriter.append(string.toString() + "\n");
myOutWriter.append(string2.toString());
myOutWriter.close();
fOut.close();
Toast.makeText(getBaseContext(),
"Gespeichert",
Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.getMessage(),
Toast.LENGTH_SHORT).show();
}
}
private void read() {
int bla;
StringBuffer strInhalt = new StringBuffer("");
try {
FileInputStream in = openFileInput("bla.txt");
while( (bla = in.read()) != -1)
strInhalt.append((char)bla);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
What can i change?`
pelase help me
I'm usin eclipse
And i would like to safe the .txt not external.
I don't believe you are creating your file correctly:
File file = new File("test.txt");
file.createNewFile();
if(file.exists())
{
OutputStream fo = new FileOutputStream(file);
fo.write("Hello World");
fo.close();
System.out.println("file created: "+file);
url = upload.upload(file);
}
And to read this file:
try {
// open the file for reading
InputStream instream = openFileInput("test.txt");
// if file the available for reading
if (instream) {
// prepare the file for reading
InputStreamReader inputreader = new InputStreamReader(instream);
BufferedReader buffreader = new BufferedReader(inputreader);
String line;
// read every line of the file into the line-variable, on line at the time
while (( line = buffreader.readLine())) {
// do something with the settings from the file
}
}
// close the file again
instream.close();
} catch (java.io.FileNotFoundException e) {
// do something if the myfilename.txt does not exits
}
And don't forget to encapsulate code with a try-catch block to catch an IOException which is thrown from these objects.
EDIT
Add this to your manifest file:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
or...
File filesDir = getFilesDir();
Scanner input = new Scanner(new File(filesDir, filename));
Hope that helps! :)
Related
I have my code generating two files with rewritable data. I need a code that continues generating the files with recursive file names and should keep all the previous files as well .
In the below code, every time i have to update my file, I have to hard code it and copy it into a new file.
I want a recursive function that saves the file, named numerically in an order(Ascending), while keeping the data in my previous file as well, everytime i run the code.
public static void main(String[] args) throws IOException
{
createFileUsingFileClass();
copyFileVersion();
fileChecker();
String data_2 = "This is the new data written in your file";
writeUsingFileWriter(data_2);
copyFileInCode(data_2);
}
private static void createFileUsingFileClass() throws IOException
{
File file = new File("C:\\Users\\esunrsa\\Documents\\file.txt");
//Create the file
if (file.createNewFile()){
System.out.println("File is created!");
}else{
System.out.println("File already exists.");
}
//Write Content
FileWriter writer = new FileWriter(file);
String data_1 = " Initial data";
writer.write(data_1);
writer.close();
}
private static void copyFileVersion() {
FileInputStream ins = null;
FileOutputStream outs = null;
try {
File infile =new File("C:\\Users\\esunrsa\\Documents\\file.txt");
File outfile =new File("C:\\Users\\esunrsa\\Documents\\file_01.txt");
ins = new FileInputStream(infile);
outs = new FileOutputStream(outfile);
byte[] buffer = new byte[1024];
int length;
while ((length = ins.read(buffer)) > 0) {
outs.write(buffer, 0, length);
}
ins.close();
outs.close();
System.out.println("File created successfully!!");
} catch(IOException ioe) {
ioe.printStackTrace();
}
}
private static void fileChecker() {
File f = new File("C:\\Users\\esunrsa\\Documents\\sunrita.txt");
if(f.exists()){
System.out.println("File existed");
}else{
System.out.println("File doesnt exist");
System.exit(0);
//System.out.println("File not found!");
}
}
private static void writeUsingFileWriter(String data_2) {
File file = new File("C:\\Users\\esunrsa\\Documents\\file.txt");
FileWriter fr = null;
try {
fr = new FileWriter(file);
fr.write(data_2);
} catch (IOException e) {
e.printStackTrace();
}finally{
//close resources
try {
fr.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
private static void copyFileInCode(String filename) {
FileInputStream ins = null;
FileOutputStream outs = null;
try {
File infile =new File("C:\\Users\\esunrsa\\Documents\\file.txt");
File outfile =new File("C:\\Users\\esunrsa\\Documents\\file_02.txt");
ins = new FileInputStream(infile);
outs = new FileOutputStream(outfile);
byte[] buffer = new byte[1024];
int length;
while ((length = ins.read(buffer)) > 0) {
outs.write(buffer, 0, length);
}
ins.close();
outs.close();
System.out.println("File created successfully!!");
} catch(IOException ioe) {
ioe.printStackTrace();
}
}
}
I know I'm not doing something correctly. I know the file needs to be Serializable to read a text file.
I've got implements Serializable on the main class. But my readText and my writeText aren't converting.
Nothing is coming in when I read and when I write out the file is not text.
public static ArrayList<String> readText() {
ArrayList<String> read = new ArrayList<String>();
Frame f = new Frame();
FileDialog foBox = new FileDialog(f, "Reading serialized file",
FileDialog.LOAD);
foBox.setVisible(true);
String foName = foBox.getFile();
String dirPath = foBox.getDirectory();
File inFile = new File(dirPath + foName);
BufferedReader in = null;
ObjectInputStream OIS = null;
try {
in = new BufferedReader(new FileReader(inFile));
} catch (FileNotFoundException e1) {
e1.printStackTrace();
}
String line = null;
try {
line = in.readLine();
} catch (IOException e1) {
e1.printStackTrace();
while (line != null) {
try {
FileInputStream IS = new FileInputStream(inFile);
OIS = new ObjectInputStream(IS);
inFile = (File) OIS.readObject();
} catch (IOException io) {
io.printStackTrace();
System.out.println("An IO Exception occurred");
}
catch (ClassNotFoundException cnf) {
cnf.printStackTrace(); // great for debugging!
System.out.println("An IO Exception occurred");
} finally
{
try {
OIS.close();
} catch (Exception e) {
}
}
}
}
return read;
}
public static void writeText(ArrayList<String> file) {
ArrayList<String> write = new ArrayList<String>();
Frame f = new Frame();
FileDialog foBox = new FileDialog(f, "Saving customer file",
FileDialog.SAVE);
foBox.setVisible(true);
String foName = foBox.getFile();
String dirPath = foBox.getDirectory();
File outFile = new File(dirPath + foName);
PrintWriter out = null;
try {
out = new PrintWriter(new BufferedWriter(new FileWriter(outFile)));
for (int i = 0; i < write.size(); i++) {
String w = write.get(i);
out.println(file.toString());
}
}
catch (IOException io) {
System.out.println("An IO Exception occurred");
io.printStackTrace();
} finally {
try {
out.close();
} catch (Exception e) {
}
}
}
Nothing is coming in
You're never calling read.add(line) and you're attempting to read the file within an infinite loop inside of the catch block, which is only entered if you are not able to read the file.
Just use one try block, meaning try to open and read the file at once, otherwise, there's no reason to continue trying to read the file if it's not able to be opened
List<String> read = new ArrayList<>();
try (BufferedReader br = new BufferedReader(new FileReader(inFile)) {
String line = null;
while ((line = in.readLine()) != null) {
read.add(line); // need this
}
} catch (Exception e) {
e.printStackTrace();
}
return read;
Now, whatever you're doing with this serialized object stuff, that's completely separate, and it isn't the file or your main class that needs set to Serializable, it's whatever object you would have used a writeObject method on. However, you're reading and writing String objects, which are already Serializable.
when I write out the file is not text
Not sure what you mean by not text, but if you followed the above code, you'll get exactly what was in the initial file... Anyway, you do not need a write list variable.
You must use the individual lines of ArrayList<String> file parameter instead, but not file.toString()
for (String line:file) {
out.println(line);
}
out.close(); // always close your files and writers
So I'm trying to basically write some logs to a text file so i can view it later. I'm running this on a physical phone, not the emulator. I've tried so many different variations, and the most i got was it writing to data/data and storage/emulated but i can never access my file. Any help would be appreciated. Some of my latest undeleted examples have been:
String filename = "myfile.txt";
try {
File path = new File(context.getFilesDir(), "myfolder");
if (!path.exists())
path.mkdir();
File output = new File(path, filename);
BufferedWriter buff = new BufferedWriter(new FileWriter(output));
buff.append("hi");
Log.d("Success",
"Successfully wrote a file " + context.getFilesDir());
} catch (Exception e) {
e.printStackTrace();
}
and
final String appPath = String.format("%s/Datafiles",
context.getFilesDir());
File path = new File(appPath);
if (!path.exists()) {
path.mkdir();
}
String fileName = String.format("%s/filedemo.txt", appPath);
and
try {
String filename = "myfile.txt";
File path = new File(Environment.getRootDirectory(), "myfolder");
if (!path.exists())
path.mkdir();
File output = new File(path, filename);
BufferedWriter buff = new BufferedWriter(new FileWriter(output));
buff.append("hi");
Log.d("Success",
"Successfully wrote a file " + context.getFilesDir());
} catch (Exception e) {
e.printStackTrace();
}
Both of the following put it under /storage/emulated/0/Android/data/com.example.simplelte/files/system/stuff/test.txt
and
/storage/emulated/0/Android/data/com.example.simplelte/files/storage/emulated/0/stuff/test.txt
respectively
try {
File file = new File(context.getExternalFilesDir(Environment
.getRootDirectory().getCanonicalPath()), "stuff");
if (!file.mkdirs()) {
Log.e(LOG_TAG, "Directory not created");
}
File output = new File(file, "test.txt");
BufferedWriter buff;
buff = new BufferedWriter(new FileWriter(output));
buff.append("hi");
buff.close();
Log.d("Success", output.getCanonicalPath());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
and
try {
File file = new File(context.getExternalFilesDir(Environment
.getExternalStorageDirectory().getCanonicalPath()),
"stuff");
if (!file.mkdirs()) {
Log.e(LOG_TAG, "Directory not created");
}
File output = new File(file, "test.txt");
BufferedWriter buff;
buff = new BufferedWriter(new FileWriter(output));
buff.append("hi");
buff.close();
Log.d("Success", output.getCanonicalPath());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
and much more. I've followed every example I can think of. I literally just want to view the text file under Computer\Nexus 5\Internal storage\ I'm just a simple man with simple desires. Why does this have to be so complicated.
Have you tried this ?
File sdCard = Environment.getExternalStorageDirectory();
File dir = new File (sdCard.getAbsolutePath() + "/");
File file = new File(dir, "text.txt");
FileOutputStream f = new FileOutputStream(file);
I have an existing text file and edited some stuff in it. I want to save a line of text to that same file. Currently, my Save button will create a new file for the text file I just edited. What I want is that my Save button will just overwrite the existing file. What code do I need to write on it?
Here's my current code:
private void btnSaveActionPerformed(java.awt.event.ActionEvent evt) {
JFileChooser fc = new JFileChooser();
int choice = fc.showSaveDialog(null);
if (choice == JFileChooser.APPROVE_OPTION) {
String filename = fc.getSelectedFile().getAbsolutePath();
writeToFile(filename);
}
}
here's my writeToFile code:
private void writeToFile(String filename) {
Person p = getPersonFromDisplay();
PersonFileMgr.save(filename, p);
}
To overwrite a file without creating a whole new file. Use FileWriter and BufferedWriter
example:
Inside your writeToFile method
try{
FileWriter fstream = new FileWriter("out.txt",true);
BufferedWriter out = new BufferedWriter(fstream);
out.write("Hi\n");
out.close();
}catch (Exception e){
System.err.println("Error: " + e.getMessage());
}
}
You could do something like this:
InputStream ios = null;
OutputStream out = null;
try {
ios = new FileInputStream(file);
byte[] buffer = new byte[SIZE];
int read;
out = new FileOutputStream(file);
while ((read = ios.read(buffer)) != -1) {
out.write(buffer, 0, read);
out.flush();
}
} catch (IOException e) {
log.error("Saving failed", e);
} finally {
if (ios != null) {
ios.close();
}
if (out != null) {
out.close();
}
}
Make the notice that in our current code you don't need several variables as choice and filename and you could inline them. There is no reason to have them.
I know of cours that here were some question about this, but I still can't find answer.
I need to write some text in external storage, but this code makes application crashed. Note that String dane is this text.
void zapis2 (String dane){
Context myContext = getApplicationContext();
File file = new File(myContext.getExternalFilesDir(null), "state.txt");
try {
FileOutputStream os = new FileOutputStream(file, true);
OutputStreamWriter out = new OutputStreamWriter(os);
out.write(dane);
out.close();}catch (IOException e) {
}
}
Have you got any idea. I add permision in android manifest of course.
Try this:
File root = android.os.Environment.getExternalStorageDirectory();
File dir = new File (root.getAbsolutePath() + "/foldername");
dir.mkdirs();
File file = new File(dir, "filename.txt");
try {
FileOutputStream f = new FileOutputStream(file);
PrintWriter pw = new PrintWriter(f);
pw.println(dane); //your string which you want to store
pw.flush();
pw.close();
f.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
Hope this helps!
Contect.getExternalFilesDir(..) is only available from API8, if you run/deploy on earler versions it will crash.