how to write image data to a text file as a base 64 string?

Question

im trying to write image data to a text file as a base 64 string its working if it doesnt contain to much information but when it contains quite a bit of information it crashes the application saying that its out off memory below is my code:

package com.search.visual;

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Environment;
import android.util.Base64;
import android.util.Log;
import android.widget.Toast;

public class SavePhotoTask extends AsyncTask<byte[], String, String>{
    String name;
    byte[] num;
    @Override
    protected String doInBackground(byte[]... params) {
        // TODO Auto-generated method stub
    File photo = new File(Environment.getExternalStorageDirectory(),".vis/image.xml");

    name = Base64.encodeToString(params[0], 0);



    //return base64String;
    if (photo.exists()){
        photo.delete();
    }
    try{



        FileWriter fi = new FileWriter(photo.getPath());
        fi.write("<Image>\n\t<Data>");
        fi.write(name);

        fi.write("</Data>\n</Image>");
        fi.close();


    }catch (IOException e) {
        // TODO: handle exception
        Log.e("pictureDemo","exception", e);
    }


    return (null);
}

    }

am i doing something wrong or is there a better way to do this?

thank you in advance

Answer 1

Sounds like you're simply running out of RAM. One reason this is happening is because you're holding the entire original image and the entire base-64 encoded image in memory, all at once, even if only briefly. Try writing the data out a chunk at a time in a for loop, using the variation:

encodeToString(byte[] input, int offset, int len, int flags)

And encoding and writing a few thousand bytes at a time