Download + Unzip example in Android

MapsDownloadService.java

package zzz.yyy.xxx.network.service;

import org.json.JSONObject;

import okhttp3.ResponseBody;
import retrofit2.Call;
import retrofit2.http.GET;

public interface MapsDownloadService {

    @GET("appversion")
    Call<JSONObject> latestAppVersion();

    @GET("static/cna_pp_v1.2.zip")
    Call<ResponseBody> downloadFileWithFixedUrl();

}

ServiceFactory.java

package zzz.yyy.xxx.network;

import java.util.concurrent.TimeUnit;

// ...

import okhttp3.OkHttpClient;
import okhttp3.logging.HttpLoggingInterceptor;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;

public enum ServiceFactory {

    AUTH(AuthService.class, "https://auth.xxx.yyy.zzz/"),
    MAP_DOWNLOAD(MapsDownloadService.class, "https://uatapi.xxx.yyy.zzz/"),

    private static final String BEARER_FORMAT = "Bearer %s";
    private static final int DEFAULT_CONNECT_TIMEOUT = 60;

    private static final Retrofit.Builder retrofitBuilder;
    private static final OkHttpClient httpClient;

    static {
        OkHttpClient.Builder httpClientBuilder = new OkHttpClient.Builder();

        if(BuildConfig.DEBUG) {
            // enable logging for debug builds
            HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor();
            loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
            httpClientBuilder
                .addInterceptor(loggingInterceptor)
                .connectTimeout(DEFAULT_CONNECT_TIMEOUT, TimeUnit.SECONDS);
        }

        httpClient = httpClientBuilder.build();
        retrofitBuilder = new Retrofit.Builder()
            .addConverterFactory(GsonConverterFactory.create());
    }


    private final Class<?> clazz;
    private final String baseUrl;

    ServiceFactory(Class<?> clazz, String baseUrl) {
        this.clazz = clazz;
        this.baseUrl = baseUrl;
    }

    public <T> T create() {
        return create(null);
    }

    @SuppressWarnings("unchecked")
    public <T> T create(String authorization) {
        OkHttpClient baseHttpClient = httpClient;

        if (authorization != null) {
            baseHttpClient = httpClient.newBuilder()
                .addInterceptor(new AuthorizationInterceptor(String.format(BEARER_FORMAT, authorization)))
                .build();
        }
        return (T) retrofitBuilder
            .baseUrl(this.baseUrl)
            .callFactory(baseHttpClient)
            .build()
            .create(this.clazz);
    }

}

SplashActivity.java

package zzz.yyy.xxx;
// ...

@EActivity(R.layout.activity_splash)
public class SplashActivity extends AbstractActivity {

    private static final String TAG = SplashActivity.class.getSimpleName();
    
    // ...
    
    private void startBitch() {
        final String path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getPath();

        if (new File(path + "/cna/6.sqlite").exists() &&
            new File(path + "/cna/18.sqlite").exists() &&
            new File(path + "/cna/62.sqlite").exists() &&
            new File(path + "/cna/90.sqlite").exists()) {
            startForGodSake();
            return;
        }
        clearDb(path);

        status.setText("Descargando base de datos..\nNo cierre la aplicación.");
        statusContainer.setVisibility(View.VISIBLE);

        downloadService.downloadFileWithFixedUrl().enqueue(new Callback<ResponseBody>() {
            @Override
            public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
                if (response.isSuccessful()) {
                    Log.d(TAG, "server contacted and has file");

                    boolean writtenToDisk = writeResponseBodyToDisk(response.body());


                    Log.d(TAG, "file download was a success? " + writtenToDisk);

                    final String path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getPath();

                    status.setText("Descarga finalizada");
                    status.postDelayed(new Runnable() {
                        @Override
                        public void run() {
                            status.setText("Descomprimiendo..\nNo cierre la aplicación.");
                            try {
                                unzip(new File(path + "/cna_pp_v1.2.zip"), new File(path));
                                status.setText("Descompresión finalizada. Iniciando..");
                                status.postDelayed(new Runnable() {
                                    @Override
                                    public void run() {
                                        startForGodSake();
                                    }
                                }, 1000);

                            } catch (IOException e) {
                                Log.e(TAG, e.getMessage(), e);
                                Toast.makeText(SplashActivity.this, "Ha ocurrido un error. Por favor vuelva a intentarlo.", Toast.LENGTH_SHORT).show();
                                clearDb(path);
                                finish();
                            }
                        }
                    }, 1000);

                } else {
                    Log.d(TAG, "server contact failed");
                    clearDb(path);

                    status.setText("Ocurrió un error. Por favor reinicie la aplicación para volver a intentar.");
                    status.postDelayed(new Runnable() {
                        @Override
                        public void run() {
                            finish();
                        }
                    }, 1500);
                }
            }

            @Override
            public void onFailure(Call<ResponseBody> call, Throwable t) {
                status.setText("Ocurrió un error. Verifique su conexión y reinicie para volver a intentar.");
                status.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        finish();
                    }
                }, 1500);
            }
        });
    }

    private void clearDb(String path) {
        new File(path + "/cna/6.sqlite").delete();
        new File(path + "/cna/18.sqlite").delete();
        new File(path + "/cna/62.sqlite").delete();
        new File(path + "/cna/90.sqlite").delete();
    }

    private boolean writeResponseBodyToDisk(ResponseBody body) {
        try {
            String path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getPath();
            File futureStudioIconFile = new File(path + File.separator + "cna_pp_v1.2.zip");

            InputStream inputStream = null;
            OutputStream outputStream = null;

            try {
                byte[] fileReader = new byte[4096];

                long fileSize = body.contentLength();
                long fileSizeDownloaded = 0;

                inputStream = body.byteStream();
                outputStream = new FileOutputStream(futureStudioIconFile);

                while (true) {
                    int read = inputStream.read(fileReader);

                    if (read == -1) {
                        break;
                    }

                    outputStream.write(fileReader, 0, read);

                    fileSizeDownloaded += read;

                    Log.d(TAG, "file download: " + fileSizeDownloaded + " of " + fileSize);
                }

                outputStream.flush();

                return true;
            } catch (IOException e) {
                return false;
            } finally {
                if (inputStream != null) {
                    inputStream.close();
                }

                if (outputStream != null) {
                    outputStream.close();
                }
            }
        } catch (IOException e) {
            return false;
        }
    }

    public static void unzip(File zipFile, File targetDirectory) throws IOException {
        ZipInputStream zis = new ZipInputStream(
            new BufferedInputStream(new FileInputStream(zipFile)));
        try {
            ZipEntry ze;
            int count;
            byte[] buffer = new byte[8192];
            while ((ze = zis.getNextEntry()) != null) {
                File file = new File(targetDirectory, ze.getName());
                File dir = ze.isDirectory() ? file : file.getParentFile();
                if (!dir.isDirectory() && !dir.mkdirs())
                    throw new FileNotFoundException("Failed to ensure directory: " +
                        dir.getAbsolutePath());
                if (ze.isDirectory())
                    continue;
                FileOutputStream fout = new FileOutputStream(file);
                try {
                    while ((count = zis.read(buffer)) != -1)
                        fout.write(buffer, 0, count);
                } finally {
                    fout.close();
                }
            }
        } finally {
            zis.close();
        }
    }
}