Question

I implemented the code to work with a async task and it works perfectly, but if user exits app it will get killed very fast, so I decided to try it with a service, it works perfectly, but it makes the app freeze.

So here’s my decompress class:

    public class Decompress {
    private String _zipFile;
    private String _location;
    ZipEntry ze = null;

    public Decompress(String zipFile, String location) {
        _zipFile = zipFile;
        _location = location;

        _dirChecker("");
    }

    public void unzip() {
        try  {
            FileInputStream fin = new FileInputStream(_zipFile);
            ZipInputStream zin = new ZipInputStream(fin);
            while ((ze = zin.getNextEntry()) != null) {
                //Log.v("Decompress", "Unzipping " + ze.getName()); 

                if(ze.isDirectory()) {
                    _dirChecker(ze.getName());
                } else {
                    FileOutputStream fout = new FileOutputStream(_location + ze.getName());
                    for (int c = zin.read(); c != -1; c = zin.read()) {
                        fout.write(c);
                    }

                    zin.closeEntry();
                    fout.close();
                } 

            }
            zin.close();
        } catch(Exception e) {
            Log.e("Decompress", "unzip", e);
        }

    }

    private void _dirChecker(String dir) {
        File f = new File(_location + dir);

        if(!f.isDirectory()) {
            f.mkdirs();
        }
    }
}

Here is my service call for unzip:

@Override
public void onStart(Intent intent, int startid)
{

    try
    {
        zipFile = intent.getStringExtra("zipFile");
        zipLocation = intent.getStringExtra("unzipLocation");
        String fileS = intent.getStringExtra("file");
        file = new File(fileS);
        fin = new FileInputStream(zipFile); 
        zin = new ZipInputStream(fin);

        while (zin.getNextEntry() != null) {
            numFiles++;
        }
    }
    catch (FileNotFoundException e)
    {}
    catch (IOException e)
    {}

    d = new Decompress(zipFile, zipLocation);
    d.unzip();

}

Now here’s how I ussed to call it with async task:

@Override
    protected Void doInBackground(Void... params) {

        d.unzip();

        return null;
    }

now my question is, why with async tsk my app don’t get freeze and it will keep unzipping letting me cancel it with a button, but with service it makes the app lags? I even got a message about MyApp not responding, Would you like to close it?

EDIT: My service call for Start

@Override
    protected Void doInBackground(Void... params) {

        Intent intent = new Intent(DownloadFiles.this, MyService.class);
        String unzipLocation = Environment.getExternalStorageDirectory().toString()+"/Android/data/";
        String zipFile = Environment.getExternalStorageDirectory().toString()+"/Android/data/test.zip"; 
        intent.putExtra("zipFile", zipFile);
        intent.putExtra("unzipLocation", unzipLocation);
        intent.putExtra("file", Environment.getExternalStorageDirectory().toString()+"/Android/data/");
        startService(intent);

        try {
            FileInputStream fin = new FileInputStream(zipFile); 
            ZipInputStream zin = new ZipInputStream(fin);

            while (zin.getNextEntry() != null) {
                 numFiles++;
                }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return null;
    }

Answer 1

Services also run in the UI (main) Thread, so you need to implement an AsyncTask or sepearate Thread approach there too.

The docs say it all under What is a Service?

A Service is not a thread. It is not a means itself to do work off of the main thread (to avoid Application Not Responding errors).

Edit: Note that if you start a Service from a background thread, the service is still running in the main thread. As per this SO answer. This should make sense as the docs say:

When a Service component is actually created, for either of these
reasons, all that the system actually does is instantiate the
component and call its onCreate() and any other appropriate callbacks
on the main thread. It is up to the Service to implement these with
the appropriate behavior, such as creating a secondary thread in which
it does its work.

This ultimately means that you should always implement a seperate AsyncTask/Thread approach in Services as well, no matter how you start the Service.