ANDROID GC_FOR_ALLOC freed in my app going wrong

Question

That's my android code which takes 30 min to copy a 3MB .log file into a .zip and gives lots of GC_FOR_ALLOC . I also tried to change buffersize from 1k to 8k

File tempFolder=new File(Environment.getExternalStorageDirectory()+LOG_FILE_DIRECTORY_TEMP); 
String filePath= Environment.getExternalStorageDirectory()+LOG_FILE_DIRECTORY_TEMP+ "/";
String fileName ="";
String zipFileName="";

String date=DATE_FORMAT_TEMP.format(new Date());
fileName = Settings.LOG_FILE_PREFIX + date+"_" + IMEI +.log; 
zipFileName = Settings.LOG_FILE_PREFIX + date+"_" + IMEI +.zip;

br = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
String result="";
String line = "";
while((line = br.readLine())!=null)
    result += line;

result = getHeader() + result;
fos = new FileOutputStream(file);
fos.write(result.getBytes());

File zipFile=new File(filePath+zipFileName);

iStream = new FileInputStream(file);
oStream = new FileOutputStream(zipFile);

zos = new ZipOutputStream(oStream);
ze = new ZipEntry(fileName);
zos.putNextEntry(ze);

byte[] buffer = new byte[1024];
while((length = iStream.read(buffer)) != -1)
    zos.write(buffer, 0, length);
zos.flush();
oStream.flush();

Answer 1

In your code it looks like you are opening and reading the file twice (your BufferedReader and your iStream object). Also, you are loading the entire file into memory twice before writing anything to memory. That's still only 6MB but you probably are hitting your memory stack limit - unless you use android:largeHeap="true" in your manifest.

Before you do that though, try just reading/writing each part:

    public void zip(String[] _files, String zipFileName) {
        try {
            BufferedInputStream origin = null;
            FileOutputStream dest = new FileOutputStream(zipFileName);
            ZipOutputStream out = new ZipOutputStream(new BufferedOutputStream(
                    dest));
            byte data[] = new byte[BUFFER];

            for (int i = 0; i < _files.length; i++) {
                Log.v("Compress", "Adding: " + _files[i]);
                FileInputStream fi = new FileInputStream(_files[i]);
                origin = new BufferedInputStream(fi, BUFFER);

                ZipEntry entry = new ZipEntry(_files[i].substring(_files[i].lastIndexOf("/") + 1));
                out.putNextEntry(entry);
                int count;

                while ((count = origin.read(data, 0, BUFFER)) != -1) {
                    out.write(data, 0, count);
                }
                origin.close();
            }

            out.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

Here is the reference: http://javatechig.com/android/how-to-programmatically-zip-and-unzip-file-in-android