Sorting ArrayList not affecting to ArrayList

Question

I am trying to sort ArrayList on the basis of String actually I have numbers in "" , like this: "4000"

I have written code to sort arraylist on the basis of price, but whenever i do tap on button it is not affecting to my ListView... why ?

I am following this tutorial....

This is how my JSON looks:

{
"locations": [
{
"name": "Office",
"price": "4,00,000"
},
{
"name": "Work",
"price": "1,20,000"
}
]
}

Model class:

public class Locations {

    private String name;
    private String price;

    public Locations() {
        // TODO Auto-generated constructor stub
    }

    public Locations(String name, String price) {
        super();
        this.name = name;
        this.price = price;
    }


    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPrice() {
        return price;
    }

    public void setPrice(String price) {
        this.price = price;
    }

}

LocationsActivity.java :

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_locations);
    actorsList = new ArrayList<Locations>();
    new JSONAsyncTask().execute(" ");

    listview = (ListView) findViewById(R.id.list);
    adapter = new LocationsAdapter(getApplicationContext(), R.layout.adapter_locations, actorsList);

    btnHTL = (Button) findViewById(R.id.btnHTL);
    btnHTL.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            Collections.sort(actorsList, new Comparator<Locations>(){
                  public int compare(Locations obj1, Locations obj2)
                  {
                      // ascending
                      return (Integer)(arg1.price).compareTo(arg2.price);
                  }
                });
            }
        }); 

    btnLTH = (Button) findViewById(R.id.btnLTH);
    btnLTH.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            Collections.sort(actorsList, new Comparator<Locations>(){
                  public int compare(Locations obj1, Locations obj2)
                  {
                      // descending
                      return (Integer)(arg2.price).compareTo(arg1.price);
                  }
                }); 
            }
        });
}

Answer 1

public class MainActivity extends Activity {

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

        Button asc = (Button) findViewById(R.id.asc);
        Button desc = (Button) findViewById(R.id.desc);
        final ArrayList<Location> actorsList = new ArrayList<Location>();

        Location loc = new Location();
        loc.setName("1");
        loc.setPrice("4000");
        actorsList.add(loc);

        loc = new Location();
        loc.setName("2");
        loc.setPrice("8000");
        actorsList.add(loc);

        loc = new Location();
        loc.setName("3");
        loc.setPrice("1000");
        actorsList.add(loc);

        loc = new Location();
        loc.setName("4");
        loc.setPrice("16000");
        actorsList.add(loc);

        asc.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Collections.sort(actorsList, new Comparator<Location>() {
                    @Override
                    public int compare(Location arg1, Location arg2) {
                        Integer obj1 = new Integer(arg1.getPrice().replace(",",""));
                        Integer obj2 = new Integer(arg2.getPrice().replace(",",""));
                        return (Integer) (obj1).compareTo(obj2);
                    }
                });

                for (int i = 0; i < actorsList.size(); i++) {
                    System.out.println("monika 1233"
                            + actorsList.get(i).getPrice());
                }
            }
        });

    }

}

Answer 2

You can use Collections.sort , which takes a comparator in argument. In the comparator you will define what you want to compare (here, the price).

Answer 3

I added code for int sorting:

Collections.sort(actorsList, new Comparator<Locations>() {
    public int compare(Locations user1, Locations user2) {
        return user1.price.compareTo(user2.price);
    }
});

And implement Comparable method in your Location model:

Locations implements Comparable<Locations>

Answer 4

Make class like this:

class PriceSort implements Comparator<location> {
    @Override
    public int compare(location cr1, location cr2) {

          long l1 = Integer.parseInt(cr1.getPrice());
          long l2 = Integer.parseInt(cr2.getPrice());
          return Long.compare(l1, l2);

    }
}

And call like:

Collections.sort(actorsList, new PriceSort());

Answer 5

If you just want to sort the list by price, use custom comparator . If you want filter the list based on any search term, use Filterable interface