How do I write to a .txt file in Android?

问题:

I have an app that needs to read and write to a text file. I have it reading, but I don't have it writing. The idea is that when I click the save button on the screen, its going to save all the info that has been put into the textviews into an array and the write each segment of the array into the text file. This is my code for the writing portion:

public class AddOrModify extends Activity {

    private Button Savebtn;
    private Button Cancelbtn;
    private EditText NameofRoute;
    private EditText Address1;
    private EditText City1;
    private EditText State1;
    private EditText Zip1;
    private EditText Address2;
    private EditText City2;
    private EditText State2;
    private EditText zip2;




        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.add_or_modify);

            Savebtn = (Button)findViewById(R.id.savebtn);
            Savebtn.setOnClickListener(new btnlistenersave());

            Cancelbtn = (Button)findViewById(R.id.cancelbtn);
            Cancelbtn.setOnClickListener(new btnlistenercancel());

        }

        private class btnlistenersave implements View.OnClickListener{
            public void onClick(View v) {

                NameofRoute = (EditText)findViewById(R.id.NameofRoute);
                Address1 = (EditText)findViewById(R.id.editAddress1);
                City1 = (EditText)findViewById(R.id.City1);
                State1= (EditText)findViewById(R.id.State1);
                Zip1 = (EditText)findViewById(R.id.Zip1);
                Address2= (EditText)findViewById(R.id.Address2);
                City2 = (EditText)findViewById(R.id.City2);
                State2 = (EditText)findViewById(R.id.State2);
                zip2 = (EditText)findViewById(R.id.Zip2);

                //String[] mySettings ={NameofRouteinput,Address1input,City1input, State1input,Zip1input,Address2input,City2input,State2input,Zip2input,";"};


               // if(mySettings != null){ 
                try{

                    String NameofRouteinput = NameofRoute.getText().toString();
                    String Address1input = Address1.getText().toString();
                    String City1input = City1.getText().toString();
                    String State1input=State1.getText().toString();
                    String Zip1input = Zip1.getText().toString();
                    String Address2input =Address2.getText().toString();
                    String City2input = City2.getText().toString();
                    String State2input = State2.getText().toString();
                    String Zip2input= zip2.getText().toString();
                    OutputStreamWriter out = new OutputStreamWriter(openFileOutput("myaddress.txt",0));

                    String[] mySettings ={NameofRouteinput,Address1input,City1input, State1input,Zip1input,Address2input,City2input,State2input,Zip2input,";"};


                    for(int i =0; i < mySettings.length; i++)
                    out.write(mySettings[i]);
                    out.close();
                }
                catch (java.io.IOException e){

                }


                Intent i = new Intent(AddOrModify.this, Frontpage.class);
                startActivity(i);

            }

        }

        private class btnlistenercancel implements View.OnClickListener{

            public void onClick(View v) {
                Intent i = new Intent(AddOrModify.this, Frontpage.class);
                startActivity(i);
            }

        }

}

回答1:

with mari's solution i was getting

       java.lang.IllegalArgumentException: contains a path separator

then i tried following and it worked for me

  File root = new File(DIRECTORY_PATH);
  File gpxfile = new File(root, "samples.txt");
  FileWriter writer = new FileWriter(gpxfile);
  writer.append("First string is here to be written.");
  writer.flush();
  writer.close();

you can loop it to write multiple lines

回答2:

You can use FileOutputStream instead of OutputStreamWriter, something like this:

File file = getFileStreamPath("test.txt");

if (!file.exists()) {
   file.createNewFile();
}

FileOutputStream writer = openFileOutput(file.getName(), Context.MODE_PRIVATE);

for (String string: data){
    writer.write(string.getBytes());
    writer.flush();
}

writer.close();

Check the android docs.