Question

I have a cities.txt file placed in my res/raw folder. Inside it contains the following.

<div class="state">Alabama</div>
<ul><li><a href="http://auburn.org">auburn</a></li>
<li><a href="http://bham.org">birmingham</a></li> </ul>

<div class="state">Alaska</div>
<ul><li><a href="http://anchorage.org">anchorage</a></li>
<li><a href="http://fairbanks.org">fairbanks</a></li></ul>

<div class="state">Arizona</div>
<ul><li><a href="http://flagstaff.org">flagstaff</a></li>
<li><a href="http://mohave.org">mohave county</a></li></ul>

I want to grab the cities for the state Alabama and display it on a ListView. The ouput should be like this.

auburn

birmingham

My current code grabs all the six cities and displays them on the ListView instead. This is my code.

package com.example.readfile;

import java.io.InputStream;
import java.util.ArrayList;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
import android.app.Activity;
import android.content.res.Resources;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class Cities extends Activity {

    ListView listUSCities;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.city_layout);
        listUSCities = (ListView) findViewById(R.id.listcities);

        new MyTask().execute();

    }

    class MyTask extends AsyncTask<Void, Void, ArrayList<String>> {

        ArrayList<String> arr_linkText = new ArrayList<String>();

        @Override
        protected ArrayList<String> doInBackground(Void... params) {

            Document doc;

            try {
                Resources res = getResources();
                InputStream in_s = res.openRawResource(R.raw.cities);

                byte[] b = new byte[in_s.available()];
                in_s.read(b);

                // Parsing using Jsoup starts here
                doc = Jsoup.parse(new String(b));

                // Parsing the states
                Elements links = doc.select("div");
                for (Element link : links) {
                    if (link.text().contains("Alabama")) {

                        // Extracting the cities
                        Elements cities = doc.select("a");
                        for (Element city : cities) {
                            arr_linkText.add(city.text());
                        }

                    }

                }

            } catch (Exception e) {
                // e.printStackTrace();

            }

            return arr_linkText; // << retrun ArrayList from here
        }

        @Override
        protected void onPostExecute(ArrayList<String> result) {
            ArrayAdapter<String> adapter = new ArrayAdapter<String>(
                    Cities.this, android.R.layout.simple_list_item_1,
                    android.R.id.text1);
            for (String temp_result : result) {

                adapter.add(temp_result);
            }
            listUSCities.setAdapter(adapter);
        }

    }

}

How can I extract the cities only for that specified state?

How do I stop parsing the file after I extracted the cities to optimize speed?

The actual cities.txtcontains more information, I only provided a sample. I will appreciate your help. Thank you!

Answer 1

That is an odd structure for an HTML document. The <div> is used just for the header, and the list is off by itself. Seeing as you trimmed the actual document, this may or may not work. The elements you are after are in the ul element following your div, so you need to go to the next sibling and search there. This will only work if there are no other elements between your div and ul elements.

Elements links = doc.select("div");
for (Element link : links) {
    if (link.text().contains("Alabama")) {
       // Extracting the cities in the list that is next in the DOM
        Elements cities = link.nextElementSibling().select("a");
        for (Element city : cities) {

            arr_linkText.add(city.text());
        }
}

}