Caching on Android

Question

I have an app which gets data from Parse.com and uses in 2 sections, one in a listView and second in a grid view.

So I want to cache this data(Strings,bitmaps),to work offline, whenever the device won't have internet so it loads from cache. And whenever my app closed and opened again, it should update the cached data if there is internet. During the update if I have the same data in my cache it shouldn't create it again, it has to only create the new ones and update the views.

What is the best way to do this in android ?. Thanks.

you can use `shared preference in android` for this because it keep data in your application cache, and it secures data. for more info follow this link-[http://stackoverflow.com/questions/23024831/android-shared-preferences-example](http://stackoverflow.com/questions/23024831/android-shared-preferences-example) — sud, Nov 23 '15 at 07:08
@sud.Thank you for your comment, I think it's not recommended to save bitmaps in shared preference, am I wrong ?. Thanks. — Shant11, Nov 23 '15 at 07:15
but practicaly you can save bitmap in shared pref but its not good practice — sud, Nov 23 '15 at 07:22
Bitmaps could be written to and retrieved from your app's local data directory. — mjp66, Nov 23 '15 at 07:44

score 1 · Answer 1 · answered Nov 23 '15 at 07:21

1

For caching a data coming form Webservice

for Get a data u can use Volley or retrofit after getting an data you can set it to user desired attributes for caching the data both library giving the caching option for saving an data try to use that library.

answered Nov 23 '15 at 07:21

santoXme

802
5
20

Thank you for your comment, I'm getting the data already and in easy way with parse.com api, I just don't know where is the best way to cache it. But yea I will try it. @antosh rawat – Shant11 Nov 23 '15 at 07:27

score 0 · Answer 2 · answered Nov 23 '15 at 07:24

0

For String / Text :

If your data amount is not so much , you can use SharedPreference
If you have huge Data you should use SQlite

For Image :

Picasso -> http://square.github.io/picasso/
Universal Image Loader -> https://github.com/nostra13/Android-Universal-Image-Loader

answered Nov 23 '15 at 07:24

Zahidul Islam

3,180
1
25
35

Thank you for your comment, so I should make a sqlite table in my app and save the info there everytime ?.@Zahidul Islam – Shant11 Nov 23 '15 at 07:31
Yes , It's easy to run CRUD operation for your data. And you can manage data in every version of your application . – Zahidul Islam Nov 23 '15 at 07:33
Okay I will give a shot. – Shant11 Nov 23 '15 at 07:38

score 0 · Answer 3 · answered Nov 23 '15 at 07:25

try this code it will help-

File cacheDir = getBaseContext().getCacheDir();
File f = new File(cacheDir, "pic");

try {
    FileOutputStream out = new FileOutputStream(
            f);
    pic.compress(
            Bitmap.CompressFormat.JPEG,
            100, out);
    out.flush();
    out.close();

} catch (FileNotFoundException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
}

Intent intent = new Intent(
        AndroidActivity.this,
        OpenPictureActivity.class);
startActivity(intent);

and then in the new activity-

public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    setContentView(R.layout.open_pic_layout);
    File cacheDir = getBaseContext().getCacheDir();
    File f = new File(cacheDir, "pic");     
    FileInputStream fis = null;
    try {
        fis = new FileInputStream(f);
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    Bitmap bitmap = BitmapFactory.decodeStream(fis);

    ImageView viewBitmap = (ImageView) findViewById(R.id.icon2);
    viewBitmap.setImageBitmap(bitmap);

Thank you for your answer, so you recommend me to write it on the local disk, am I right ? .@sud — Shant11, Nov 23 '15 at 07:29
read this you will be get more clear about `cachedir` [http://stackoverflow.com/questions/13731203/why-to-use-getcachedir-on-android](http://stackoverflow.com/questions/13731203/why-to-use-getcachedir-on-android) — sud, Nov 23 '15 at 07:38

Caching on Android

3 Answers3