public void onClick(View v) {
            WebServiceC webService = WebServiceC();

            epubDownloaded = webService.downloadEpub(publi.getId());
             File fileEpub=new File(Environment.getExternalStorageDirectory(), "test.epub");
             if (fileEpub.exists()) {
                fileEpub.delete();
              }
             try {
                    FileOutputStream fos=new FileOutputStream(arquivoEpub.getPath());

                    fos.write(epubDownloaded);
                    fos.close();
                  }catch (IOException e) {
                        e.printStackTrace();
                    }
        }

    });

int count;
                    WebServiceC webService = new WebServiceC();

                    epubDownloaded = webService.downloadEpub(publi.getId());

                    InputStream input = new ByteArrayInputStream(epubDownloaded);
                    OutputStream output = null;
                    try {
                        output = new FileOutputStream(Environment.getExternalStorageDirectory()+"/test.epub");
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    }
                    byte data[] = new byte[1024];

                    try {
                        while ((count = input.read(data)) != -1) {

                            output.write(data, 0, count);
                        }
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }