Ejemplo obtener XML, AsyncTask. Curso de desarrollo de aplicaciones Android.

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="tech.alvarez.ejemploxml">

    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Evento.java

package tech.alvarez.ejemploxml.models;

import java.util.Date;

/**
 * Created by Daniel Alvarez on 14/7/16.
 * Copyright © 2016 Alvarez.tech. All rights reserved.
 */
public class Evento {

    private String nombre;
    private String lugar;
    private Date fecha;

    public String getNombre() {
        return nombre;
    }

    public void setNombre(String nombre) {
        this.nombre = nombre;
    }

    public String getLugar() {
        return lugar;
    }

    public void setLugar(String lugar) {
        this.lugar = lugar;
    }

    public Date getFecha() {
        return fecha;
    }

    public void setFecha(Date fecha) {
        this.fecha = fecha;
    }
}

MainActivity.java

package tech.alvarez.ejemploxml;

import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;

import java.util.ArrayList;

import tech.alvarez.ejemploxml.models.Evento;
import tech.alvarez.ejemploxml.utils.ParserXML;

public class MainActivity extends AppCompatActivity {

    private ArrayList<Evento> eventos;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        String url = "https://docs.google.com/uc?export=download&id=0B5wCprFP-EBZd29KNjNlaDFfOFk";

        ObtenerXMLTask obtenerXMLTask = new ObtenerXMLTask();
        obtenerXMLTask.execute(url);
    }

    public class ObtenerXMLTask extends AsyncTask<String, Void, Boolean> {

        @Override
        protected Boolean doInBackground(String... strings) {

            String url = strings[0];

            ParserXML parserXML = new ParserXML(url);
            eventos = parserXML.parse();

            return null;
        }

        @Override
        protected void onPostExecute(Boolean aBoolean) {
            super.onPostExecute(aBoolean);

            for (int i = 0; i < eventos.size(); i++) {
                Evento e = eventos.get(i);
                Log.i("MIAPP", "Evento");
                Log.i("MIAPP", " Nombre: " + e.getNombre());
                Log.i("MIAPP", " Lugar: " + e.getLugar());
                Log.i("MIAPP", " Fecha: " + e.getFecha());
            }

        }
    }
}

ParserXML.java

package tech.alvarez.ejemploxml.utils;


import android.sax.Element;
import android.sax.EndElementListener;
import android.sax.EndTextElementListener;
import android.sax.RootElement;
import android.sax.StartElementListener;
import android.util.Xml;

import org.xml.sax.Attributes;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;

import tech.alvarez.ejemploxml.models.Evento;

/**
 * Created by Daniel Alvarez on 14/7/16.
 * Copyright © 2016 Alvarez.tech. All rights reserved.
 */

public class ParserXML {

    private URL url;
    private Evento eventoActual;

    public ParserXML(String url) {
        try {
            this.url = new URL(url);
        } catch (MalformedURLException e) {
            throw new RuntimeException(e);
        }
    }

    public ArrayList<Evento> parse() {

        final ArrayList<Evento> eventos = new ArrayList<Evento>();

        RootElement root = new RootElement("eventos");
        Element item = root.getChild("evento");

        item.setStartElementListener(new StartElementListener() {
            @Override
            public void start(Attributes attributes) {
                eventoActual = new Evento();
            }
        });


        item.getChild("nombre").setEndTextElementListener(new EndTextElementListener() {
            @Override
            public void end(String s) {
                eventoActual.setNombre(s);
            }
        });

        item.getChild("lugar").setEndTextElementListener(new EndTextElementListener() {
            @Override
            public void end(String s) {
                eventoActual.setLugar(s);
            }
        });

        item.getChild("fecha").setEndTextElementListener(new EndTextElementListener() {
            @Override
            public void end(String s) {
                eventoActual.setFecha(convertir(s));
            }
        });

        item.setEndElementListener(new EndElementListener() {
            @Override
            public void end() {
                eventos.add(eventoActual);
            }
        });

        try {
            Xml.parse(getInputStream(), Xml.Encoding.UTF_8, root.getContentHandler());
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }

        return eventos;
    }


    private InputStream getInputStream() {
        try {
            return url.openConnection().getInputStream();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    // Método extra
    public static Date convertir(String fechaString) {
        SimpleDateFormat format = new SimpleDateFormat("dd/MM/yyyy");
        Date date = null;
        try {
            date = format.parse(fechaString);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return date;
    }
}