Java – Write text files in Java

I have an application that needs an experienced Java expert (probably just a glance). The engine works perfectly, but I can’t save the data to a text file; Also, every time I debug a file operation, I have to bind (bind) my tablet, uninstall the old app, copy the apk, and then reinstall it because I can’t write to disk in the emulator.

I added:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

to

list outside of the application tag, and tried several ways to write to a file. The exception is (depending on the current attempt) eacces or the file does not exist. I also googled all day to find a solution. Does anyone know?

// this is a canned method that should presumably work
 private void writeStringToTextFile(String s, String f){
File sdCard = Environment.getExternalStorageDirectory();
File dir = new File (sdCard.getAbsolutePath());
dir.mkdirs();
File file = new File(dir, f);
try{
    FileOutputStream f1 = new FileOutputStream(file,false); True = Append to file, false = Overwrite
    PrintStream p = new PrintStream(f1);
    p.print(s);
    p.close();
    f1.close();
} catch (FileNotFoundException e) {
} catch (IOException e) {
}   }

 this is the save method
 it has been modified a little less than a million times today
 some lines may be unnecessary because I have tried several approaches
  public void saveSystem(View view){
          String s="";
          String FILENAME = "data/data/TopExpertAndroid/" + fileName;
          FileOutputStream f;
          File file = new File(FILENAME);
          if(!( file.exists())){
             try{
                 file.createNewFile(); } 
             catch(Exception e){
                showSplash(e.getMessage() + e.getCause(), "OK");
                return; }}
          try{
              getFile();
              if(fileName.equals("")){}
              else{
                   f = openFileOutput(FILENAME, Context.MODE_PRIVATE);
                   for(int temp=0; temp<50; temp++){
                       for(int loop=0; loop<50; loop++){
                           s += topExpert.nodeBank[temp][loop].activationResponse + "\n";
                           s += topExpert.nodeBank[temp][loop].display + "\n";
                           s += topExpert.nodeBank[temp][loop].falseLink + "\n";
                           s += topExpert.nodeBank[temp][loop].identifier + "\n";
                           if(topExpert.nodeBank[temp][loop].isTop){
                              s += "true"; }
                           else{
                                s += "false"; }
                           s += "\n" + topExpert.nodeBank[temp][loop].trueLink + "\n"; }}
                           writeStringToTextFile(s,FILENAME);
              }}
          catch(Exception e){
                showSplash(e.getMessage() + e.getCause(), "OK"); }}

THE

FILENAME VARIABLE MAY BE MISSING A /: AT THE BEGINNING

String FILENAME = "/data/data/TopExpertAndroid/" + fileName;

You should use getDataDirectory or getExternalStorageDirectory On the contrary….

But what you said about disks that can’t be written to the emulator seems strange…?