Passing an arraylist of arraylists

Question

I know it\'s a commonly asked question and I looked at the solutions online, but I am having a difficulty implementing this on my own.

I have a class which contains thr

Answer 1

Ok.

Your Model

public class ImageHolder implements Serializable {

    // Use String here, to avoid serialization problems
    private String uri;
    private Date date;
    private Location loc;

    public ImageHolder() {
    }

    public ImageHolder(String uri, Date date, Location loc) {
        this.uri = uri;
        this.date = date;
        this.loc = loc;
    }

    public String getUri() {
        return uri;
    }

    public void setUri(String uri) {
        this.uri = uri;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    public Location getLoc() {
        return loc;
    }

    public void setLoc(Location loc) {
        this.loc = loc;
    }

    @Override
    public String toString() {
        return "ImageHolder{" +
                "uri=" + uri +
                ", date=" + date +
                ", loc=" + loc +
                '}';
    }
}

Create a Container class

public class Container implements Serializable {

    private ArrayList list;

    public Container() {
    }

    public Container(ArrayList list) {
        this.list = list;
    }

    public ArrayList getList() {
        return list;
    }

    public void setList(ArrayList list) {
        this.list = list;
    }

    @Override
    public String toString() {
        return "Container{" +
                "list=" + list +
                '}';
    }
}

Your First Activity

public class MainActivity extends AppCompatActivity {

    public static final String TAG = MainActivity.class.getSimpleName();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_activity);
    }

    @Override
    protected void onPostCreate(@Nullable Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);

        ImageHolder imageHolder0 = new ImageHolder("http://www.stackoverflow.com", new Date(), new Location("test0"));
        ImageHolder imageHolder1 = new ImageHolder("http://www.google.com", new Date(), new Location("test1"));

        ArrayList list = new ArrayList<>();
        list.add(imageHolder0);
        list.add(imageHolder1);

        Container container = new Container(list);

        Gson gson = new Gson();
        String json = gson.toJson(container);

        Intent intent = new Intent(MainActivity.this, TestActivity.class);
        intent.putExtra("yourKey", json);

        startActivity(intent);
    }
}

Your second activity

public class TestActivity extends AppCompatActivity {
    public static final String TAG = TestActivity.class.getSimpleName();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    protected void onPostCreate(@Nullable Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);

        Gson gson = new Gson();
        Container container = gson.fromJson(getIntent().getStringExtra("yourKey"), Container.class);

        Log.d(TAG, "OK?" + container.getList().toString());

        // Here convert String uri Fields to Uri Objects
        // Example:
        Uri uri = Uri.parse(container.getList().get(0).getUri());
    }
}

Logcat result: 08-01 11:10:22.097 6671-6671/it.darksurfer.english.template D/TestActivity: OK?[ImageHolder{uri=http://www.stackoverflow.com, date=Wed Aug 01 11:10:21 GMT+02:00 2018, loc=Location[test0 0,000000,0,000000 acc=??? t=?!? et=?!?]}, ImageHolder{uri=http://www.google.com, date=Wed Aug 01 11:10:21 GMT+02:00 2018, loc=Location[test1 0,000000,0,000000 acc=??? t=?!? et=?!?]}]

Obviously you can put an undefined number of others ArrayList in the list of Container class!