I have a simple android app that uses jSoup to get data from a URL. I have a dirty solution with TOAST giving me a warning of on or offline. I would like to be able to have the data from the last time the user queried for new information stored incase the user is offline. I am not sure where to start? I read about Data Cache, SQLite, etc...
What would be the best way to store the data from the jsoup parse so I can retrieve it if the user is offline?
Here is my code so far:
public class SlockActivity extends SherlockActivity {
private TextView textView;
private String url = "http://www.backcountryskiers.com/sac/sac-full.html";
private String noDangerUrl = "http://www.sierraavalanchecenter.org/sites/default/files/images/danger_icons_and_bars/0_nodangerrate.png";
private ImageView image;
private TextView tvWX;
// GLOBAL RESOURCES
private static SlockActivity instance = null;
// private ProgressDialog dialog = new ProgressDialog(SlockActivity.this);
@Override
public boolean onCreateOptionsMenu(Menu menu) {
menu.add("Emergency")
.setIcon(R.drawable.emergencyicon)
.setShowAsAction(
MenuItem.SHOW_AS_ACTION_IF_ROOM
| MenuItem.SHOW_AS_ACTION_WITH_TEXT);
menu.add("Weather")
.setIcon(R.drawable.wx_icon)
.setShowAsAction(
MenuItem.SHOW_AS_ACTION_IF_ROOM
| MenuItem.SHOW_AS_ACTION_WITH_TEXT);
menu.add("Refresh")
.setIcon(R.drawable.ic_refresh)
.setShowAsAction(
MenuItem.SHOW_AS_ACTION_IF_ROOM
| MenuItem.SHOW_AS_ACTION_WITH_TEXT);
return true;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById(R.id.todaysReport);
image = (ImageView) findViewById(R.id.dangerRose);
tvWX = (TextView) findViewById(R.id.todaysWX);
boolean check = isOnline();
if (check == true) {
Toast.makeText(this, "Internet is Connected", Toast.LENGTH_LONG)
.show();
fetcher task = new fetcher();
task.execute();
}
else {
Toast.makeText(this, "Failed to connect to internet.",
Toast.LENGTH_LONG).show();
textView.setText("No Network Connection and attempt to get Cached Data did not work. ");
}
}
public static Bitmap getBitmapFromURL(String src) {
try {
Log.e("src", src);
URL url = new URL(src);
HttpURLConnection connection = (HttpURLConnection) url
.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
Log.e("Bitmap", "returned");
return myBitmap;
} catch (IOException e) {
e.printStackTrace();
Log.e("Exception", e.getMessage());
return null;
}
}
class fetcher extends AsyncTask<String, Void, String> {
// HERE DECLARE THE VARIABLES YOU USE FOR PARSING
private ProgressDialog dialog = new ProgressDialog(SlockActivity.this);
private Document doc = null;
private Elements content = null;
private Document parse = null;
private String results = null;
private Element dangerRatingImg = null;
private String dangerRatingSrc = null;
private Bitmap bimage;
@Override
protected String doInBackground(String... params) {
try {
doc = Jsoup.connect(url).get();
Log.e("Jsoup", "...is working...");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.e("Exception", e.getMessage());
}
content = doc.select("#content");
parse = Jsoup.parse(doc.html());
results = doc.select("#content").outerHtml();
// find rating image...
dangerRatingImg = doc.select("img").first();
dangerRatingSrc = dangerRatingImg.absUrl("src");
// Get the rating image
bimage = getBitmapFromURL(dangerRatingSrc);
return results;
}
@Override
protected void onPostExecute(String result) {
dialog.dismiss();
// smooth out the long scrolling...
textView.setMovementMethod(ScrollingMovementMethod.getInstance());
// Set this after the load so the background is the picture without
// the textviews background in
textView.setBackgroundResource(R.drawable.tvbg);
// Set the rating image
//
// DO THE IMAGE REPLACE ON URL COMPARE THING HERE>>>>>>>
if (dangerRatingSrc.equals(noDangerUrl)) {
image.setImageDrawable(getResources().getDrawable(
R.drawable.nodanger));
}
//
// image.setImageBitmap(bimage);
image.setPadding(0, 10, 0, 30);
// image.setScaleType(ScaleType.FIT_XY);
// return the summary
results = parse.select("#reportSummary").outerHtml();
// String reportDate = parse.select("#reportDate").outerHtml();
textView.setText(Html.fromHtml(results));
// textView.append(Html.fromHtml("<a href='#'><em>Read Full Report »</em></a>"));
textView.setPadding(30, 20, 20, 10);
// ditch the dialog, it's all loaded.
tvWX.setText(Html.fromHtml("Today's High: <b>26F</b>"));
}
@Override
protected void onPreExecute() {
// before we get the async results show this
dialog.setMessage("Loading Latest Update from the Sierra Avalanche Center...");
dialog.show();
}
}
// check network connectivity
public boolean isOnline() {
ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netInfo = cm.getActiveNetworkInfo();
if (netInfo != null && netInfo.isConnectedOrConnecting()) {
Log.i("Network", "IS CONNECTED");
return true;
}
Log.i("Network", "IS NOT-CONNECTED");
return false;
}
public void onClickFullReport(View v) {
Intent intentFullReport = new Intent(getBaseContext(),
FullReportActivity.class);
intentFullReport.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
startActivity(intentFullReport);
}
}
I would suggest writing the String to a file only readable to your app as described in the documentation: http://developer.android.com/guide/topics/data/data-storage.html#filesInternal
To write "data" to file "filename.txt":
String FILENAME = "filename.txt";
String string = "data";
FileOutputStream fos = openFileOutput(FILENAME, Context.MODE_PRIVATE);
fos.write(string.getBytes());
fos.close();
To read it again:
FileInputStream fis = context.openFileInput(FILENAME);
StringBuffer fileContent = new StringBuffer("");
byte[] buffer = new byte[1024];
int length;
while ((length = fis.read(buffer)) != -1) {
fileContent.append(new String(buffer));
}
String string = fileContent.toString();