This are android tutorials for downloading,parsing and rendering RSS Feeds. We use AsyncTask,XmlPullParser and HttpURLConnection to achieve these. Our adapterview is the ListView.

Example 1 – Android RSS – ListView – Download,Parse,Show Headlines

This is an android RSS example with XmlPullParser,AsyncTask ,HttpURLConnection and ListView..We shall download RSS Feeds from a local website and then parse the feed.We then show parsed images and text news in our ListView.

What we do :

• Connect to Internet and make a HTTP GET request using HtttpURLConnection.
• Download our data in the background thread.
• WE use AsyncTask for our threading.
• WE parse the downloaded xml feeds.
• We shall be parsing using XmlPullParser.
• We show our results in a ListView.
• Our results shall consist of images and text.
• The website we shall be parsing was hosted locally and it was a dummy wordpress site.

SECTION 1 : Our Dependencies and Manifest

AndroidManifest.xml

• Remember we are downloading data from a network.
• Hence we need to add permission to access the internet.
• Or else Android won’t allow us establish connection.

<?xml version="1.0" encoding="utf-8"?>
<manifest 
    package="com.tutorials.hp.simplelistviewrss">

    <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"
            android_label="@string/app_name"
            android_theme="@style/AppTheme.NoActionBar">
            <intent-filter>
                <action android_name="android.intent.action.MAIN" />

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

</manifest>

SECTION 2 : Our Networking and Parsing classes

Connector class

Main Responsibility : ESTABLISH CONNECTION.

• Establishes connection to our server for us.
• We then set up connection properties like Request method.
• In this case we are making a HTTP GET request to our server.
• We shall use HttpURLConnection so our only method shall return its instance .

package com.tutorials.hp.simplelistviewrss.m_RSS;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class Connector {

    public static Object connect(String urlAddress)
    {
        try
        {
            URL url=new URL(urlAddress);
            HttpURLConnection con= (HttpURLConnection) url.openConnection();

            con.setRequestMethod("GET");
            con.setConnectTimeout(15000);
            con.setReadTimeout(15000);
            con.setDoInput(true);

            return con;

        } catch (MalformedURLException e) {
            e.printStackTrace();
            return ErrorTracker.WRONG_URL_FORMAT;

        } catch (IOException e) {
            e.printStackTrace();
            return ErrorTracker.CONNECTION_ERROR;
        }
    }

}

Downloader class

Main Responsibility : DOWNLOAD XML FEEDS.

• We use our Connector class above to establish a connection.
• If we have a connection then we download data XML feeds from server.
• We download in background using AsyncTask to avoid freezing our user interface.
• Meanwhile we show progress dialog while downloading.
• We dismiss our progress dialog on completion.
• Then we send this downloaded xml feeds to our Data Parser class for it to be processed.

package com.tutorials.hp.simplelistviewrss.m_RSS;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.ListView;
import android.widget.Toast;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;

public class Downloader extends AsyncTask<Void,Void,Object> {

    Context c;
    String urlAddress;
    ListView lv;

    ProgressDialog pd;

    public Downloader(Context c, String urlAddress, ListView lv) {
        this.c = c;
        this.urlAddress = urlAddress;
        this.lv = lv;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pd=new ProgressDialog(c);
        pd.setTitle("Fetch Headlines");
        pd.setMessage("Fetching....Please wait");
        pd.show();
    }

    @Override
    protected Object doInBackground(Void... params) {
        return this.downloadData();
    }

    @Override
    protected void onPostExecute(Object data) {
        super.onPostExecute(data);
        pd.dismiss();

        if(data.toString().startsWith("Error"))
        {
            Toast.makeText(c,data.toString(),Toast.LENGTH_SHORT).show();
        }else {
            //PARSE
            new RSSParser(c, (InputStream) data,lv).execute();
        }
    }

    private Object downloadData()
    {
        Object connection=Connector.connect(urlAddress);
        if(connection.toString().startsWith("Error"))
        {
            return connection.toString();
        }

        try
        {
            HttpURLConnection con= (HttpURLConnection) connection;
            InputStream is=new BufferedInputStream(con.getInputStream());

            return is;

        } catch (IOException e) {
            e.printStackTrace();
            return ErrorTracker.IO_EROR;
        }
    }
}

RSS Parser class

Main Responsibility : DOWNLOAD XML FEEDS.

• It receives raw XML feeds from downloader class.
• It then processes/parses these feeds.
• We use XmlPullParser to parse the feeds.
• It then fills an arraylist of Article Objects with our results.
• It then sends this arraylist to adapter for binding purposes.

package com.tutorials.hp.simplelistviewrss.m_RSS;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;

public class RSSParser extends AsyncTask<Void,Void,Boolean> {

    Context c;
    InputStream is;
    ListView lv;

    ProgressDialog pd;
    ArrayList<String> headlines=new ArrayList<>();

    public RSSParser(Context c, InputStream is, ListView lv) {
        this.c = c;
        this.is = is;
        this.lv = lv;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pd=new ProgressDialog(c);
        pd.setTitle("Parse Data");
        pd.setMessage("Parsing...Please wait");
        pd.show();
    }

    @Override
    protected Boolean doInBackground(Void... params) {
        return this.parseRSS();
    }

    @Override
    protected void onPostExecute(Boolean isParsed) {
        super.onPostExecute(isParsed);
        pd.dismiss();
        if(isParsed)
        {
            //BIND
            lv.setAdapter(new ArrayAdapter<String>(c,android.R.layout.simple_list_item_1,headlines));

        }else {
            Toast.makeText(c,"Unable To Parse",Toast.LENGTH_SHORT).show();
        }
    }

    private Boolean parseRSS()
    {
        try
        {
            XmlPullParserFactory factory=XmlPullParserFactory.newInstance();
            XmlPullParser parser=factory.newPullParser();

            //SET STREAM
            parser.setInput(is,null);
            headlines.clear();
            String headline=null;
            Boolean isWebsiteTitle=true;

            int event=parser.getEventType();

            do {
                String name=parser.getName();

                switch (event)
                {
                    case XmlPullParser.START_TAG:
                        break;

                    case XmlPullParser.TEXT:
                        headline=parser.getText();
                        break;

                    case XmlPullParser.END_TAG:
                        if(isWebsiteTitle)
                        {
                            isWebsiteTitle=false;
                        }else if(name.equals("title"))
                        {
                            headlines.add(headline);
                        }
                        break;
                }

                event=parser.next();

            }while (event != XmlPullParser.END_DOCUMENT);

            return true;

        } catch (XmlPullParserException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return false;
    }
}

Error Tracker class

Main Responsibility : HELP US TRACK CONNECTION EXCEPTIONS AT RUNTIME

•  Consists of constants that we shall display when we encounter error at runtime.

package com.tutorials.hp.simplelistviewrss.m_RSS;

public class ErrorTracker {

    public final static String WRONG_URL_FORMAT="Error : Wrong URL Format";
    public final static String CONNECTION_ERROR="Error : Unable To Establish Connection";
    public final static String IO_EROR="Error : Unable To Read";

}

SECTION 3 : Our Activity

MainActivity class.

Main Responsibility : LAUNCH OUR APP.

• We shall reference the views like ListView and Floating action button here,from our XML Layouts.
• We then execute our Downloader class when Floating action button is clicked.
• We shall also define here our feeds url and parse the data.

package com.tutorials.hp.simplelistviewrss;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.ListView;

import com.tutorials.hp.simplelistviewrss.m_RSS.Downloader;

public class MainActivity extends AppCompatActivity {

    final static String urlAddress="http://10.0.2.2/galacticnews/index.php/feed/";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);

        final ListView lv= (ListView) findViewById(R.id.lv);

        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                new Downloader(MainActivity.this,urlAddress,lv).execute();
            }
        });
    }

}

SECTION 5 : Our Layouts

ActivityMain.xml Layout.

• Inflated as our activity’s view.
• Includes our content main.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
    
    
    android_layout_width="match_parent"
    android_layout_height="match_parent"
    android_fitsSystemWindows="true"
    tools_context="com.tutorials.hp.simplelistviewrss.MainActivity">

    <android.support.design.widget.AppBarLayout
        android_layout_width="match_parent"
        android_layout_height="wrap_content"
        android_theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android_id="@+id/toolbar"
            android_layout_width="match_parent"
            android_layout_height="?attr/actionBarSize"
            android_background="?attr/colorPrimary"
            app_popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

    <include layout="@layout/content_main" />

    <android.support.design.widget.FloatingActionButton
        android_id="@+id/fab"
        android_layout_width="wrap_content"
        android_layout_height="wrap_content"
        android_layout_gravity="bottom|end"
        android_layout_margin="@dimen/fab_margin"
        android_src="@android:drawable/ic_dialog_email" />

</android.support.design.widget.CoordinatorLayout>

ContentMain.xml Layout.

• Defines our view hierarchy.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
    
    
    android_layout_width="match_parent"
    android_layout_height="match_parent"
    android_paddingBottom="@dimen/activity_vertical_margin"
    android_paddingLeft="@dimen/activity_horizontal_margin"
    android_paddingRight="@dimen/activity_horizontal_margin"
    android_paddingTop="@dimen/activity_vertical_margin"
    app_layout_behavior="@string/appbar_scrolling_view_behavior"
    tools_context="com.tutorials.hp.simplelistviewrss.MainActivity"
    tools_showIn="@layout/activity_main">

    <ListView
        android_id="@+id/lv"
        android_layout_width="wrap_content"
        android_layout_height="wrap_content"
         />
</RelativeLayout>

 

Example 2 – Android RSS – ListView Multiple Fields – Download,Parse,Show

This is an android RSS example with XmlPullParser,AsyncTask ,HttpURLConnection and ListView..We shall download RSS Feeds from a local website and then parse the feed.We then show parsed images and text news in our ListView.

What we do :

• Connect to Internet and make a HTTP GET request using HtttpURLConnection.
• Download our data in the background thread.
• WE use AsyncTask for our threading.
• WE parse the downloaded xml feeds.
• We shall be parsing using XmlPullParser.
• We show our results in a ListView.
• Our results shall consist of images and text.
• The website we shall be parsing was hosted locally and it was a dummy wordpress site.

Cheers.

SECTION 1 : Our Data Object

Article.java

• Represents a single article.
• The article shall have various properties like name,description,title,date etc.

package com.tutorials.hp.listviewrssmulti_items.m_DataObject;

public class Article {

    String title,description,date,link;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getDate() {
        return date;
    }

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

    public String getLink() {
        return link;
    }

    public void setLink(String link) {
        this.link = link;
    }
}

SECTION 3 : Our Networking and Parsing classes

Connector class

Main Responsibility : ESTABLISH CONNECTION.

• Establishes connection to our server for us.
• We then set up connection properties like Request method.
• In this case we are making a HTTP GET request to our server.
• We shall use HttpURLConnection so our only method shall return its instance .

package com.tutorials.hp.listviewrssmulti_items.m_RSS;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class Connector {

    public static Object connect(String urlAddress)
    {
        try
        {
            URL url=new URL(urlAddress);
            HttpURLConnection con= (HttpURLConnection) url.openConnection();

            con.setRequestMethod("GET");
            con.setConnectTimeout(15000);
            con.setReadTimeout(15000);
            con.setDoInput(true);

            return con;

        } catch (MalformedURLException e) {
            e.printStackTrace();
            return ErrorTracker.WRONG_URL_FORMAT;

        } catch (IOException e) {
            e.printStackTrace();
            return ErrorTracker.CONNECTION_ERROR;
        }
    }
}

Downloader class

Main Responsibility : DOWNLOAD XML FEEDS.

• We use our Connector class above to establish a connection.
• If we have a connection then we download data XML feeds from server.
• We download in background using AsyncTask to avoid freezing our user interface.
• Meanwhile we show progress dialog while downloading.
• We dismiss our progress dialog on completion.
• Then we send this downloaded xml feeds to our Data Parser class for it to be processed.

package com.tutorials.hp.listviewrssmulti_items.m_RSS;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.ListView;
import android.widget.Toast;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;

public class Downloader extends AsyncTask<Void,Void,Object> {

    Context c;
    String urlAddress;
    ListView lv;

    ProgressDialog pd;

    public Downloader(Context c, String urlAddress, ListView lv) {
        this.c = c;
        this.urlAddress = urlAddress;
        this.lv = lv;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pd=new ProgressDialog(c);
        pd.setTitle("Fetch data");
        pd.setMessage("Fetching Data...Please wait");
        pd.show();
    }

    @Override
    protected Object doInBackground(Void... params) {
        return this.downloadData();
    }

    @Override
    protected void onPostExecute(Object data) {
        super.onPostExecute(data);
        pd.dismiss();

        if(data.toString().startsWith("Error"))
        {
            Toast.makeText(c,data.toString(),Toast.LENGTH_SHORT).show();
        }else {
            //PARSE
            new RSSParser(c, (InputStream) data,lv).execute();
        }
    }

    private Object downloadData()
    {
        Object connection=Connector.connect(urlAddress);
        if(connection.toString().startsWith("Error"))
        {
            return connection.toString();
        }

        try
        {
            HttpURLConnection con= (HttpURLConnection) connection;
            int responseCode=con.getResponseCode();
            if(responseCode==con.HTTP_OK)
            {
                InputStream is=new BufferedInputStream(con.getInputStream());
                return is;
            }

            return ErrorTracker.RESPONSE_ERROR+con.getResponseMessage();

        } catch (IOException e) {
            e.printStackTrace();
            return ErrorTracker.IO_EROR;
        }
    }
}

RSS Parser class

Main Responsibility : DOWNLOAD XML FEEDS.

• It receives raw XML feeds from downloader class.
• It then processes/parses these feeds.
• We use XmlPullParser to parse the feeds.
• It then fills an arraylist of Article Objects with our results.
• It then sends this arraylist to adapter for binding purposes.

package com.tutorials.hp.listviewrssmulti_items.m_RSS;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.ListView;
import android.widget.Toast;

import com.tutorials.hp.listviewrssmulti_items.m_DataObject.Article;
import com.tutorials.hp.listviewrssmulti_items.m_UI.CustomAdapter;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;

public class RSSParser extends AsyncTask<Void,Void,Boolean> {

    Context c;
    InputStream is;
    ListView lv;

    ProgressDialog pd;
    ArrayList<Article> articles=new ArrayList<>();

    public RSSParser(Context c, InputStream is, ListView lv) {
        this.c = c;
        this.is = is;
        this.lv = lv;
    }
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pd=new ProgressDialog(c);
        pd.setTitle("Parse data");
        pd.setMessage("Parsing Data...Please wait");
        pd.show();
    }

    @Override
    protected Boolean doInBackground(Void... params) {
        return this.parseRSS();
    }

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

        pd.dismiss();
        if(isParsed)
        {
            //BIND
            lv.setAdapter(new CustomAdapter(c,articles));
        }else {
            Toast.makeText(c,"Unable To Parse",Toast.LENGTH_SHORT).show();
        }
    }

    private Boolean parseRSS()
    {
        try
        {
            XmlPullParserFactory factory=XmlPullParserFactory.newInstance();
            XmlPullParser parser=factory.newPullParser();

            parser.setInput(is,null);
            int event=parser.getEventType();

            String value=null;
            articles.clear();
            Article article=new Article();

            do {

                String name=parser.getName();

                switch (event)
                {
                    case XmlPullParser.START_TAG:
                        if(name.equals("item"))
                        {
                            article=new Article();
                        }
                        break;

                    case XmlPullParser.TEXT:
                        value=parser.getText();
                        break;

                    case XmlPullParser.END_TAG:
                        if(name.equals("title"))
                        {
                            article.setTitle(value);
                        }else if(name.equals("description"))
                        {
                            article.setDescription(value);
                        }else if(name.equals("pubDate"))
                        {
                            article.setDate(value);
                        }else if(name.equals("link"))
                        {
                            article.setLink(value);
                        }

                        if(name.equals("item"))
                        {
                            articles.add(article);
                        }

                        break;
                }

                event=parser.next();

            }while (event != XmlPullParser.END_DOCUMENT);

            return true;

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

        return false;
    }
}

Error Tracker class

Main Responsibility : HELP US TRACK CONNECTION EXCEPTIONS AT RUNTIME

•  Consists of constants that we shall display when we encounter error at runtime.

package com.tutorials.hp.listviewrssmulti_items.m_RSS;

public class ErrorTracker {

    public final static String WRONG_URL_FORMAT="Error : Wrong URL Format";
    public final static String CONNECTION_ERROR="Error : Unable To Establish Connection";
    public final static String IO_EROR="Error : Unable To Read";
    public final static String RESPONSE_ERROR="Error : Bad Response - ";

}

SECTION 3 : Adapter class

Custom Adapter class

Main Responsibility : HELPS US BIND CUSTOM DATA TO LISTVIEW.

• You can use one line of code to bind simple data to listview.
• But for custom data like ours,we need an adapter to adapt it.
• We shall use BaseAdapter as our Base class.
• Our BaseAdapter subclass shall receive an arraylist and a context.

package com.tutorials.hp.listviewrssmulti_items.m_UI;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import android.widget.Toast;

import com.tutorials.hp.listviewrssmulti_items.R;
import com.tutorials.hp.listviewrssmulti_items.m_DataObject.Article;

import java.util.ArrayList;

public class CustomAdapter extends BaseAdapter {

    Context c;
    ArrayList<Article> articles;

    public CustomAdapter(Context c, ArrayList<Article> articles) {
        this.c = c;
        this.articles = articles;
    }

    @Override
    public int getCount() {
        return articles.size();
    }

    @Override
    public Object getItem(int position) {
        return articles.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if(convertView==null)
        {
            convertView= LayoutInflater.from(c).inflate(R.layout.model,parent,false);
        }

        TextView titleTxt= (TextView) convertView.findViewById(R.id.titleTxt);
        TextView descTxt= (TextView) convertView.findViewById(R.id.descTxt);
        TextView dateTxt= (TextView) convertView.findViewById(R.id.dateTxt);

        final Article article= (Article) this.getItem(position);

        titleTxt.setText(article.getTitle());
        descTxt.setText(article.getDescription().substring(0, 120));
        dateTxt.setText(article.getDate());

        convertView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(c, article.getTitle(), Toast.LENGTH_SHORT).show();
            }
        });

        return convertView;
    }
}

SECTION 4 : Our Activity

MainActivity class.

Main Responsibility : LAUNCH OUR APP.

• We shall reference the views like ListView and Floating action button here,from our XML Layouts.
• We then execute our Downloader class when Floating action button is clicked.
• We shall also define here our feeds url and parse the data.

package com.tutorials.hp.listviewrssmulti_items;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListView;

import com.tutorials.hp.listviewrssmulti_items.m_RSS.Downloader;

public class MainActivity extends AppCompatActivity {

    final static String urlAddress="http://10.0.2.2/galacticnews/index.php/feed";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);

        final ListView lv= (ListView) findViewById(R.id.lv);

        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                new Downloader(MainActivity.this,urlAddress,lv).execute();
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

SECTION 5 : Our Layouts

ActivityMain.xml Layout.

• Inflated as our activity’s view.
• Includes our content main.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
    
    
    android_layout_width="match_parent"
    android_layout_height="match_parent"
    android_fitsSystemWindows="true"
    tools_context="com.tutorials.hp.listviewrssmulti_items.MainActivity">

    <android.support.design.widget.AppBarLayout
        android_layout_width="match_parent"
        android_layout_height="wrap_content"
        android_theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android_id="@+id/toolbar"
            android_layout_width="match_parent"
            android_layout_height="?attr/actionBarSize"
            android_background="?attr/colorPrimary"
            app_popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

    <include layout="@layout/content_main" />

    <android.support.design.widget.FloatingActionButton
        android_id="@+id/fab"
        android_layout_width="wrap_content"
        android_layout_height="wrap_content"
        android_layout_gravity="bottom|end"
        android_layout_margin="@dimen/fab_margin"
        android_src="@android:drawable/ic_dialog_email" />

</android.support.design.widget.CoordinatorLayout>

ContentMain.xml Layout.

• Defines our view hierarchy.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
    
    
    android_layout_width="match_parent"
    android_layout_height="match_parent"
    android_paddingBottom="@dimen/activity_vertical_margin"
    android_paddingLeft="@dimen/activity_horizontal_margin"
    android_paddingRight="@dimen/activity_horizontal_margin"
    android_paddingTop="@dimen/activity_vertical_margin"
    app_layout_behavior="@string/appbar_scrolling_view_behavior"
    tools_context="com.tutorials.hp.listviewrssmulti_items.MainActivity"
    tools_showIn="@layout/activity_main">

    <ListView
        android_id="@+id/lv"
        android_layout_width="wrap_content"
        android_layout_height="wrap_content"
         />
</RelativeLayout>

Model.xml Layout.

• Inflated as our AdapterView’s viewitems.

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView 
    android_orientation="horizontal" android_layout_width="match_parent"
    
    android_layout_margin="10dp"
    card_view_cardCornerRadius="5dp"
    card_view_cardElevation="5dp"
    android_layout_height="200dp">

    <LinearLayout
        android_orientation="vertical"
        android_layout_width="match_parent"
        android_layout_height="match_parent">
        <TextView
            android_layout_width="match_parent"
            android_layout_height="wrap_content"
            android_textAppearance="?android:attr/textAppearanceLarge"
            android_text="Title"
            android_id="@+id/titleTxt"
            android_padding="10dp"
            android_textColor="@color/colorAccent"
            android_textStyle="bold"
            android_layout_alignParentLeft="true"
            />

            <TextView
                android_layout_width="wrap_content"
                android_layout_height="wrap_content"
                android_textAppearance="?android:attr/textAppearanceLarge"
                android_text="Description....................."
                android_lines="3"
                android_id="@+id/descTxt"
                android_padding="10dp"

                android_layout_alignParentLeft="true"
                />

            <TextView
                android_layout_width="wrap_content"
                android_layout_height="wrap_content"
                android_textAppearance="?android:attr/textAppearanceMedium"
                android_text="Date"
                android_textStyle="italic"
                android_id="@+id/dateTxt" />

    </LinearLayout>

</android.support.v7.widget.CardView>

 

Example 3 – Android RSS – ListView Master Detail – Download,Parse,Show Headlines [Open Activity]

 

This is an android RSS Master Detail example with XmlPullParser,AsyncTask ,HttpURLConnection and ListView.We shall download RSS Feeds from a local website and then parse the feed.We then show parsed images and text news in our ListView. We shall handle ItemClicks for our ListView’s ViewItems and open the detail activity,passing in details over there.

What we do :

• Connect to Internet and make a HTTP GET request using HtttpURLConnection.
• Download our data in the background thread.
• WE use AsyncTask for our threading.
• WE parse the downloaded xml feeds.
• We shall be parsing using XmlPullParser.
• We show our results in a ListView.
• This is our master view.It has our ListView.
• When a single ListView viewitem is clicked,we open detail activity.
• The detail view shall show details of a single news feed,like title,description,date etc.
• The website we shall be parsing was hosted locally and it was a dummy wordpress site.

Let’s dive in at the deep end.

SECTION 1 : Our Dependencies and Manifest

AndroidManifest.xml

• Remember we are downloading data from a network.
• Hence we need to add permission to access the internet.
• Or else Android won’t allow us establish connection.

<?xml version="1.0" encoding="utf-8"?>
<manifest 
    package="com.tutorials.hp.listviewrssmdetail">

    <uses-permission android_name="android.permission.INTERNET"/>


</manifest>

SECTION 2 : Our Data Object

Article.java

• Represents a single article.
• The article shall have various properties like name,title,description,date etc.

package com.tutorials.hp.listviewrssmdetail.m_DataObject;

public class Article {

    String title,description,date,guid,link;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getDate() {
        return date;
    }

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

    public String getGuid() {
        return guid;
    }

    public void setGuid(String guid) {
        this.guid = guid;
    }

    public String getLink() {
        return link;
    }

    public void setLink(String link) {
        this.link = link;
    }
}

SECTION 3 : Our Networking and Parsing classes

Connector class

Main Responsibility : ESTABLISH CONNECTION.

• Establishes connection to our server for us.
• We then set up connection properties like Request method.
• In this case we are making a HTTP GET request to our server.
• We shall use HttpURLConnection so our only method shall return its instance .

package com.tutorials.hp.listviewrssmdetail.m_RSS;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class Connector {

    public static Object connect(String urlAddress)
    {
        try
        {
            URL url=new URL(urlAddress);
            HttpURLConnection con= (HttpURLConnection) url.openConnection();

            con.setRequestMethod("GET");
            con.setConnectTimeout(15000);
            con.setReadTimeout(15000);
            con.setDoInput(true);

            return con;

        } catch (MalformedURLException e) {
            e.printStackTrace();
            return ErrorTracker.WRONG_URL_FORMAT;

        } catch (IOException e) {
            e.printStackTrace();
            return ErrorTracker.CONNECTION_ERROR;
        }
    }
}

Downloader class

Main Responsibility : DOWNLOAD XML FEEDS.

• We use our Connector class above to establish a connection.
• If we have a connection then we download data XML feeds from server.
• We download in background using AsyncTask to avoid freezing our user interface.
• Meanwhile we show progress dialog while downloading.
• We dismiss our progress dialog on completion.
• Then we send this downloaded xml feeds to our Data Parser class for it to be processed.

package com.tutorials.hp.listviewrssmdetail.m_RSS;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.ListView;
import android.widget.Toast;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;

public class Downloader extends AsyncTask<Void,Void,Object> {

    Context c;
    String urlAddress;
    ListView lv;

    ProgressDialog pd;

    public Downloader(Context c, String urlAddress, ListView lv) {
        this.c = c;
        this.urlAddress = urlAddress;
        this.lv = lv;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pd=new ProgressDialog(c);
        pd.setTitle("Fetch Articles");
        pd.setMessage("Fetching...Please wait");
        pd.show();

    }

    @Override
    protected Object doInBackground(Void... params) {
        return this.downloadData();
    }

    @Override
    protected void onPostExecute(Object data) {
        super.onPostExecute(data);

        pd.dismiss();
        if(data.toString().startsWith("Error"))
        {
            Toast.makeText(c,data.toString(),Toast.LENGTH_SHORT).show();
        }else {
            //PARSER CLASS
            new RSSParser(c, (InputStream) data,lv).execute();

        }
    }

    private Object downloadData()
    {
        Object connection=Connector.connect(urlAddress);
        if(connection.toString().startsWith("Error"))
        {
            return connection.toString();
        }

        try
        {
            HttpURLConnection con= (HttpURLConnection) connection;
            int responseCode=con.getResponseCode();

            if(responseCode==con.HTTP_OK)
            {
                InputStream is=new BufferedInputStream(con.getInputStream());
                return is;
            }

            return ErrorTracker.RESPONSE_EROR+con.getResponseMessage();

        } catch (IOException e) {
            e.printStackTrace();
            return ErrorTracker.IO_EROR;
        }

    }
}

RSS Parser class

Main Responsibility : DOWNLOAD XML FEEDS.

• It receives raw XML feeds from downloader class.
• It then processes/parses these feeds.
• We use XmlPullParser to parse the feeds.
• It then fills an arraylist of Article Objects with our results.
• It then sends this arraylist to adapter for binding purposes.

package com.tutorials.hp.listviewrssmdetail.m_RSS;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.ListView;
import android.widget.Toast;

import com.tutorials.hp.listviewrssmdetail.m_DataObject.Article;
import com.tutorials.hp.listviewrssmdetail.m_UI.CustomAdapter;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;

public class RSSParser extends AsyncTask<Void,Void,Boolean> {

    Context c;
    InputStream is;
    ListView lv;

    ProgressDialog pd;
    ArrayList<Article> articles=new ArrayList<>();

    public RSSParser(Context c, InputStream is, ListView lv) {
        this.c = c;
        this.is = is;
        this.lv = lv;
    }
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pd=new ProgressDialog(c);
        pd.setTitle("Parse Articles");
        pd.setMessage("Parsing...Please wait");
        pd.show();

    }

    @Override
    protected Boolean doInBackground(Void... params) {
        return this.parseRSS();
    }

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

        pd.dismiss();
        if(isParsed)
        {
            //BIND

            lv.setAdapter(new CustomAdapter(c,articles));

        }else {
            Toast.makeText(c,"Unable To Parse",Toast.LENGTH_SHORT).show();
        }
    }
    private Boolean parseRSS()
    {
        try
        {
            XmlPullParserFactory factory=XmlPullParserFactory.newInstance();
            XmlPullParser parser=factory.newPullParser();

            parser.setInput(is,null);
            int event=parser.getEventType();

            String tagValue=null;
            Boolean isSiteMeta=true;

            articles.clear();
            Article article=new Article();

            do {

                String tagName=parser.getName();

                switch (event)
                {
                    case XmlPullParser.START_TAG:
                        if(tagName.equalsIgnoreCase("item"))
                        {
                            article=new Article();
                            isSiteMeta=false;
                        }
                        break;

                    case XmlPullParser.TEXT:
                        tagValue=parser.getText();
                        break;

                    case XmlPullParser.END_TAG:

                        if(!isSiteMeta)
                        {
                            if(tagName.equalsIgnoreCase("title"))
                            {
                                article.setTitle(tagValue);
                            }else if(tagName.equalsIgnoreCase("description"))
                            {
                                article.setDescription(tagValue);

                            }else if(tagName.equalsIgnoreCase("pubDate"))
                            {
                                article.setDate(tagValue);

                            }else if(tagName.equalsIgnoreCase("guid"))
                            {
                                article.setGuid(tagValue);

                            }else if(tagName.equalsIgnoreCase("link"))
                            {
                                article.setLink(tagValue);

                            }
                        }

                        if(tagName.equalsIgnoreCase("item"))
                        {
                            articles.add(article);
                            isSiteMeta=true;
                        }
                        break;
                }

                event=parser.next();

            }while (event != XmlPullParser.END_DOCUMENT);

            return true;

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

        return false;
    }
}

Error Tracker class

Main Responsibility : HELP US TRACK CONNECTION EXCEPTIONS AT RUNTIME

•  Consists of constants that we shall display when we encounter error at runtime.

package com.tutorials.hp.listviewrssmdetail.m_RSS;

public class ErrorTracker {

    public final static String WRONG_URL_FORMAT="Error : Wrong URL Format";
    public final static String CONNECTION_ERROR="Error : Unable To Establish Connection";
    public final static String IO_EROR="Error : Unable To Read";
    public final static String RESPONSE_EROR="Error : Bad Response - ";

}

SECTION 3 : Adapter class

Custom Adapter class

Main Responsibility : HELPS US BIND CUSTOM DATA TO LISTVIEW.

• You can use one line of code to bind simple data to listview.
• But for custom data like ours,we need an adapter to adapt it.
• We shall use BaseAdapter as our Base class.
• Our BaseAdapter subclass shall receive an arraylist and a context.

package com.tutorials.hp.listviewrssmdetail.m_UI;

import android.content.Context;
import android.content.Intent;
import android.text.Html;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.tutorials.hp.listviewrssmdetail.R;
import com.tutorials.hp.listviewrssmdetail.m_DataObject.Article;
import com.tutorials.hp.listviewrssmdetail.m_DetailActivity.DetailActivity;

import java.util.ArrayList;

public class CustomAdapter extends BaseAdapter {

    Context c;
    ArrayList<Article> articles;

    public CustomAdapter(Context c, ArrayList<Article> articles) {
        this.c = c;
        this.articles = articles;
    }

    @Override
    public int getCount() {
        return articles.size();
    }

    @Override
    public Object getItem(int position) {
        return articles.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if(convertView==null)
        {
            convertView= LayoutInflater.from(c).inflate(R.layout.model,parent,false);
        }

        TextView titleTxt= (TextView) convertView.findViewById(R.id.titleTxt);
        TextView descTxt= (TextView) convertView.findViewById(R.id.descTxt);
        TextView dateTxt= (TextView) convertView.findViewById(R.id.dateTxt);

        Article article= (Article) this.getItem(position);

        final String title=article.getTitle();
        final String desc=article.getDescription();
        final String date=article.getDate();
        final String guid=article.getGuid();
        final String link=article.getLink();

        titleTxt.setText(title);
        descTxt.setText(Html.fromHtml(desc));
        dateTxt.setText(date);

        convertView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //OPEN DETAIL ACTIVITY
                openDetailActivity(title,desc,date,guid,link);
            }
        });

        return convertView;
    }
    private void openDetailActivity(String...details)
    {
        Intent i=new Intent(c, DetailActivity.class);

        i.putExtra("TITLE_KEY",details[0]);
        i.putExtra("DESC_KEY",details[1]);
        i.putExtra("DATE_KEY",details[2]);
        i.putExtra("GUID_KEY",details[3]);
        i.putExtra("LINK_KEY",details[4]);

        c.startActivity(i);
    }
}

SECTION 4 : Our Activities

Detail Activity class.

Main Responsibility : DISPLAY SINGLE NEWS ARTICLE DETAILS

• Data shall be passed via Bundle from MainActivity.
• So we simply unpack that data.
• Then show it in our views.

package com.tutorials.hp.listviewrssmdetail.m_DetailActivity;

import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.text.Html;
import android.view.View;
import android.widget.TextView;

import com.tutorials.hp.listviewrssmdetail.R;

public class DetailActivity extends AppCompatActivity {

    TextView titleTxt,descTxt,dateTxt,guidTxt,linkTxt;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_detail);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);

        titleTxt= (TextView) findViewById(R.id.titleDetailTxt);
        descTxt= (TextView) findViewById(R.id.descDetailTxt);
        dateTxt= (TextView) findViewById(R.id.dateDetailTxt);
        guidTxt= (TextView) findViewById(R.id.guidDetailTxt);
        linkTxt= (TextView) findViewById(R.id.linkDetailTxt);

        Intent i=this.getIntent();

        String title=i.getExtras().getString("TITLE_KEY");
        String desc=i.getExtras().getString("DESC_KEY");
        String date=i.getExtras().getString("DATE_KEY");
        String guid=i.getExtras().getString("GUID_KEY");
        String link=i.getExtras().getString("LINK_KEY");

        titleTxt.setText(title);
        descTxt.setText(Html.fromHtml(desc));
        dateTxt.setText(date);
        guidTxt.setText(guid);
        linkTxt.setText(link);

        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
    }

}

MainActivity class. Main Responsibility : LAUNCH OUR APP.

• We shall reference the views like ListView and Floating action button here,from our XML Layouts.
• We then execute our Downloader class when Floating action button is clicked.
• We shall also define here our feeds url and parse the data.

package com.tutorials.hp.listviewrssmdetail;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListView;

import com.tutorials.hp.listviewrssmdetail.m_RSS.Downloader;

public class MainActivity extends AppCompatActivity {

    final static String urlAddress="http://10.0.2.2/galacticnews/index.php/feed";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);

        final ListView lv= (ListView) findViewById(R.id.lv);

        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                new Downloader(MainActivity.this,urlAddress,lv).execute();
            }
        });
    }
}

SECTION 5 : Our Layouts

MAINACTIVITY LAYOUTS

ActivityMain.xml Layout.

• Inflated as our activity’s view.
• Includes our content main.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
    
    
    android_layout_width="match_parent"
    android_layout_height="match_parent"
    android_fitsSystemWindows="true"
    tools_context="com.tutorials.hp.listviewrssmdetail.MainActivity">

    <android.support.design.widget.AppBarLayout
        android_layout_width="match_parent"
        android_layout_height="wrap_content"
        android_theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android_id="@+id/toolbar"
            android_layout_width="match_parent"
            android_layout_height="?attr/actionBarSize"
            android_background="?attr/colorPrimary"
            app_popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

    <include layout="@layout/content_main" />

    <android.support.design.widget.FloatingActionButton
        android_id="@+id/fab"
        android_layout_width="wrap_content"
        android_layout_height="wrap_content"
        android_layout_gravity="bottom|end"
        android_layout_margin="@dimen/fab_margin"
        android_src="@android:drawable/ic_dialog_email" />

</android.support.design.widget.CoordinatorLayout>

ContentMain.xml Layout.

• Defines our view hierarchy.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
    
    
    android_layout_width="match_parent"
    android_layout_height="match_parent"
    android_paddingBottom="@dimen/activity_vertical_margin"
    android_paddingLeft="@dimen/activity_horizontal_margin"
    android_paddingRight="@dimen/activity_horizontal_margin"
    android_paddingTop="@dimen/activity_vertical_margin"
    app_layout_behavior="@string/appbar_scrolling_view_behavior"
    tools_context="com.tutorials.hp.listviewrssmdetail.MainActivity"
    tools_showIn="@layout/activity_main">

    <ListView
        android_id="@+id/lv"
        android_layout_width="wrap_content"
        android_layout_height="wrap_content"
         />
</RelativeLayout>

Model.xml Layout.

• Inflated as our ListView’s viewitems.

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView 
    android_orientation="horizontal" android_layout_width="match_parent"
    
    android_layout_margin="10dp"
    card_view_cardCornerRadius="5dp"
    card_view_cardElevation="5dp"
    android_layout_height="200dp">

        <LinearLayout
            android_orientation="vertical"
            android_layout_width="match_parent"
            android_layout_height="match_parent">

            <TextView
                android_layout_width="match_parent"
                android_layout_height="wrap_content"
                android_textAppearance="?android:attr/textAppearanceLarge"
                android_text="Title"
                android_id="@+id/titleTxt"
                android_padding="10dp"
                android_textColor="@color/colorAccent"
                android_textStyle="bold"
                android_layout_alignParentLeft="true"
                />

            <TextView
                android_layout_width="wrap_content"
                android_layout_height="wrap_content"
                android_textAppearance="?android:attr/textAppearanceLarge"
                android_text="Description....................."
                android_lines="3"
                android_id="@+id/descTxt"
                android_padding="10dp"
                android_layout_alignParentLeft="true"
                />

            <TextView
                android_layout_width="wrap_content"
                android_layout_height="wrap_content"
                android_textAppearance="?android:attr/textAppearanceMedium"
                android_text="Date"
                android_textStyle="italic"
                android_id="@+id/dateTxt" />

    </LinearLayout>

</android.support.v7.widget.CardView>

DETAILACTIVITY LAYOUTS

ActivityDetail.xml Layout.

• Inflated as our  detail activity’s view.
• Includes our content detail.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
    
    
    android_layout_width="match_parent"
    android_layout_height="match_parent"
    android_fitsSystemWindows="true"
    tools_context="com.tutorials.hp.gridviewrssmdetail.m_DetailActivity.DetailActivity">

    <android.support.design.widget.AppBarLayout
        android_layout_width="match_parent"
        android_layout_height="wrap_content"
        android_theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android_id="@+id/toolbar"
            android_layout_width="match_parent"
            android_layout_height="?attr/actionBarSize"
            android_background="?attr/colorPrimary"
            app_popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

    <include layout="@layout/content_detail" />

    <android.support.design.widget.FloatingActionButton
        android_id="@+id/fab"
        android_layout_width="wrap_content"
        android_layout_height="wrap_content"
        android_layout_gravity="bottom|end"
        android_layout_margin="@dimen/fab_margin"
        android_src="@android:drawable/ic_dialog_email" />

</android.support.design.widget.CoordinatorLayout>

ContentDetail.xml Layout.

• Defines our detail view hierarchy.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
    
    
    android_layout_width="match_parent"
    android_layout_height="match_parent"
    android_paddingBottom="@dimen/activity_vertical_margin"
    android_paddingLeft="@dimen/activity_horizontal_margin"
    android_paddingRight="@dimen/activity_horizontal_margin"
    android_paddingTop="@dimen/activity_vertical_margin"
    app_layout_behavior="@string/appbar_scrolling_view_behavior"
    tools_context="com.tutorials.hp.gridviewrssmdetail.m_DetailActivity.DetailActivity"
    android_background="#009688"
    tools_showIn="@layout/activity_detail">

    <android.support.v7.widget.CardView 
        android_orientation="horizontal" android_layout_width="match_parent"
        
        android_layout_margin="5dp"
        card_view_cardCornerRadius="10dp"
        card_view_cardElevation="5dp"

        android_layout_height="match_parent">

        <LinearLayout
            android_orientation="vertical"
            android_layout_width="match_parent"
            android_layout_height="match_parent"
            android_weightSum="1">

            <LinearLayout
                android_orientation="horizontal"
                android_layout_width="match_parent"
                android_layout_height="wrap_content">

                <ImageView
                    android_id="@+id/articleDetailImg"
                    android_layout_width="320dp"
                    android_layout_height="wrap_content"
                    android_paddingLeft="10dp"
                    android_layout_alignParentTop="true"
                    android_scaleType="centerCrop"
                    android_src="@drawable/spitzer" />

                <LinearLayout
                    android_orientation="vertical"
                    android_layout_width="match_parent"
                    android_layout_height="wrap_content">

                <TextView
                    android_id="@+id/titleDetailTxt"
                    android_layout_width="wrap_content"
                    android_layout_height="wrap_content"
                    android_textAppearance="?android:attr/textAppearanceLarge"
                    android_padding="5dp"
                    android_minLines="1"
                    android_textStyle="bold"
                    android_textColor="@color/colorAccent"
                    android_text="Title" />
                <TextView
                    android_id="@+id/dateDetailTxt"
                    android_layout_width="wrap_content"
                    android_layout_height="wrap_content"
                    android_textAppearance="?android:attr/textAppearanceLarge"
                    android_padding="5dp"
                    android_minLines="1"
                    android_text="DATE" />

                   </LinearLayout>
            </LinearLayout>
            <TextView
                android_id="@+id/guidDetailTxt"
                android_layout_width="wrap_content"
                android_layout_height="wrap_content"
                android_textAppearance="?android:attr/textAppearanceMedium"
                android_padding="5dp"
                android_minLines="1"
                android_text="GUID" />
            <LinearLayout
                android_layout_width="fill_parent"
                android_layout_height="match_parent"
                android_layout_marginTop="?attr/actionBarSize"
                android_orientation="vertical"
                android_paddingLeft="5dp"
                android_paddingRight="5dp"
                android_paddingTop="5dp">

                <TextView
                    android_id="@+id/linkDetailTxt"
                    android_layout_width="wrap_content"
                    android_layout_height="wrap_content"
                    android_textAppearance="?android:attr/textAppearanceMedium"
                    android_padding="5dp"
                    android_textColor="@color/colorPrimaryDark"
                    android_textStyle="italic"
                    android_text="Link" />

                    <TextView
                        android_id="@+id/descDetailTxt"
                        android_layout_width="wrap_content"
                        android_layout_height="wrap_content"
                        android_textAppearance="?android:attr/textAppearanceLarge"
                        android_padding="5dp"
                        android_textColor="#0f0f0f"
                        android_minLines="4"
                        android_text="John Doe joined this company on January May 1995 beforesome of you were born.He's been with us through thick and thin.When he came for the first time,he was naive and nervous.Now he is an experienced talent...." />

            </LinearLayout>
        </LinearLayout>
    </android.support.v7.widget.CardView>

</RelativeLayout>

 

Example 4 – Android RSS – ListView – Headlines With Images and Text

Android RSS Listview images and text example. This is an android RSS images listview example with XmlPullParser,AsyncTask ,HttpURLConnection and ListView..We shall download RSS Feeds from a local website and then parse the feed.We then show parsed images and text news in our ListView.

What we do :

• Connect to Internet and make a HTTP GET request using HtttpURLConnection.
• Download our data in the background thread.
• WE use AsyncTask for our threading.
• WE parse the downloaded xml feeds.
• We shall be parsing using XmlPullParser.
• We show our results in a ListView.
• Our results shall consist of images and text.
• The website we shall be parsing was hosted locally and it was a dummy wordpress site.

Enough.Let’s now dive to the deep end.

SECTION 1 : Our Dependencies and Manifest.

AndroidManifest.xml

• Remember we are downloading data from a network.
• Hence we need to add permission to access the internet.
• Or else Android won’t accept our request for connection.

<?xml version="1.0" encoding="utf-8"?>
<manifest 
    package="com.tutorials.hp.listviewrssimagestext">

    <uses-permission android_name="android.permission.INTERNET"/>

</manifest>

SECTION 2 : Our Data Object

Article.java

• Represents a single article.
• The article shall have various properties like name,title,date etc.

package com.tutorials.hp.listviewrssimagestext.m_DataObject;

public class Article {

    String title,description,date,imageUrl;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getDate() {
        return date;
    }

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

    public String getImageUrl() {
        return imageUrl;
    }

    public void setImageUrl(String imageUrl) {
        this.imageUrl = imageUrl;
    }
}

SECTION 3 : Our Networking and Parsing classes

Connector class

Main Responsibility : ESTABLISH CONNECTION.

• Establishes connection to our server for us.
• We then set up connection properties like Request method.
• In this case we are making a HTTP GET request to our server.
• We shall use HttpURLConnection so our only method shall return its instance .

package com.tutorials.hp.listviewrssimagestext.m_RSS;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class Connector {

    public static Object connect(String urlAddress)
    {
        try
        {
            URL url=new URL(urlAddress);
            HttpURLConnection con= (HttpURLConnection) url.openConnection();

            //PROPERTIES
            con.setRequestMethod("GET");
            con.setConnectTimeout(15000);
            con.setReadTimeout(15000);
            con.setDoInput(true);

            return con;

        } catch (MalformedURLException e) {
            e.printStackTrace();
            return ErrorTracker.WRONG_URL_FORMAT;

        } catch (IOException e) {
            e.printStackTrace();
            return ErrorTracker.CONNECTION_ERROR;
        }
    }

}

Downloader class

Main Responsibility : DOWNLOAD XML FEEDS.

• We use our Connector class above to establish a connection.
• If we have a connection then we download data XML feeds from server.
• We download in background using AsyncTask to avoid freezing our user interface.
• Meanwhile we show progress dialog while downloading.
• We dismiss our progress dialog on completion.
• Then we send this downloaded xml feeds to our Data Parser class for it to be processed.

package com.tutorials.hp.listviewrssimagestext.m_RSS;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.ListView;
import android.widget.Toast;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;

public class Downloader extends AsyncTask<Void,Void,Object> {

    Context c;
    String urlAddress;
    ListView lv;

    ProgressDialog pd;

    public Downloader(Context c, String urlAddress, ListView lv) {
        this.c = c;
        this.urlAddress = urlAddress;
        this.lv = lv;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pd=new ProgressDialog(c);
        pd.setTitle("Fetch Articles");
        pd.setMessage("Fetching...Please wait");
        pd.show();
    }

    @Override
    protected Object doInBackground(Void... params) {
        return this.downloadData();
    }

    @Override
    protected void onPostExecute(Object data) {
        super.onPostExecute(data);
        pd.dismiss();
        if(data.toString().startsWith("Error"))
        {
            Toast.makeText(c,data.toString(),Toast.LENGTH_SHORT).show();
        }else {
            //PARSE RSS
            new RSSParser(c, (InputStream) data,lv).execute();
        }

    }

    private Object downloadData()
    {
        Object connection=Connector.connect(urlAddress);
        if(connection.toString().startsWith("Error"))
        {
            return connection.toString();
        }

        try
        {
            HttpURLConnection con= (HttpURLConnection) connection;
            int responseCode=con.getResponseCode();
            if(responseCode==con.HTTP_OK)
            {
                InputStream is=new BufferedInputStream(con.getInputStream());
                return is;
            }

            return ErrorTracker.RESPONSE_EROR+con.getResponseMessage();

        } catch (IOException e) {
            e.printStackTrace();
            return ErrorTracker.IO_EROR;
        }
    }
}

RSS Parser class

Main Responsibility : DOWNLOAD XML FEEDS.

• It receives raw XML feeds from downloader class.
• It then processes/parses these feeds.
• We use XmlPullParser to parse the feeds.
• It then fills an arraylist of Article Objects with our results.
• It then sends this arraylist to adapter for binding purposes.

package com.tutorials.hp.listviewrssimagestext.m_RSS;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.ListView;
import android.widget.Toast;

import com.tutorials.hp.listviewrssimagestext.m_DataObject.Article;
import com.tutorials.hp.listviewrssimagestext.m_UI.CustomAdapter;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;

public class RSSParser extends AsyncTask<Void,Void,Boolean> {

    Context c;
    InputStream is;
    ListView lv;

    ProgressDialog pd;
    ArrayList<Article> articles=new ArrayList<>();

    public RSSParser(Context c, InputStream is, ListView lv) {
        this.c = c;
        this.is = is;
        this.lv = lv;
    }
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pd=new ProgressDialog(c);
        pd.setTitle("Parse RSS");
        pd.setMessage("Parsing...Please wait");
        pd.show();
    }

    @Override
    protected Boolean doInBackground(Void... params) {
        return this.parseRSS();
    }

    @Override
    protected void onPostExecute(Boolean isParsed) {
        super.onPostExecute(isParsed);
        pd.dismiss();
        if(isParsed)
        {
            //BIND
            lv.setAdapter(new CustomAdapter(c,articles));

        }else {
            Toast.makeText(c,"Unable To Parse",Toast.LENGTH_SHORT).show();
        }
    }

    private Boolean parseRSS()
    {
        try
        {
            XmlPullParserFactory factory=XmlPullParserFactory.newInstance();
            XmlPullParser parser=factory.newPullParser();

            parser.setInput(is,null);
            int event=parser.getEventType();

            String tagValue=null;
            Boolean isSiteMeta=true;

            articles.clear();
            Article article=new Article();

            do {

                String tagName=parser.getName();

                switch (event)
                {
                    case XmlPullParser.START_TAG:
                        if(tagName.equalsIgnoreCase("item"))
                        {
                            article=new Article();
                            isSiteMeta=false;
                        }
                        break;

                    case XmlPullParser.TEXT:
                        tagValue=parser.getText();
                        break;

                    case XmlPullParser.END_TAG:

                        if(!isSiteMeta)
                        {
                            if(tagName.equalsIgnoreCase("title"))
                            {
                                article.setTitle(tagValue);

                            }else if(tagName.equalsIgnoreCase("description"))
                            {
                                String desc=tagValue;
                                article.setDescription(desc.substring(desc.indexOf("/>")+2));

                                //EXTRACT IMAGE FROM DESCRIPTION
                                String imageUrl=desc.substring(desc.indexOf("src=")+5,desc.indexOf("jpg")+3);
                                article.setImageUrl(imageUrl);

                            }else if(tagName.equalsIgnoreCase("pubDate"))
                            {
                                article.setDate(tagValue);
                            }
                        }

                        if(tagName.equalsIgnoreCase("item"))
                        {
                            articles.add(article);
                            isSiteMeta=true;
                        }

                        break;
                }

                event=parser.next();

            }while (event != XmlPullParser.END_DOCUMENT);

            return true;

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

        return false;
    }
}

Error Tracker class

Main Responsibility : HELP US TRACK CONNECTION EXCEPTIONS AT RUNTIME

•  Consists of constants that we shall display when we encounter error at runtime.

package com.tutorials.hp.listviewrssimagestext.m_RSS;

public class ErrorTracker {

    public final static String WRONG_URL_FORMAT="Error : URL Format is not valid";
    public final static String CONNECTION_ERROR="Error : Unable To Establish Connection";
    public final static String IO_EROR="Error : Unable To Read";
    public final static String RESPONSE_EROR="Error : Bad Response - ";

}

SECTION 3 : Adapter class

Custom Adapter class

Main Responsibility : HELPS US BIND CUSTOM DATA TO LISTVIEW.

• You can use one line of code to bind simple data to listview.
• But for custom data like ours,we need an adapter to adapt it.
• We shall use BaseAdapter as our Base class.
• Our BaseAdapter subclass shall receive an arraylist and a context.

package com.tutorials.hp.listviewrssimagestext.m_UI;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import com.tutorials.hp.listviewrssimagestext.R;
import com.tutorials.hp.listviewrssimagestext.m_DataObject.Article;

import java.util.ArrayList;

public class CustomAdapter extends BaseAdapter {
    Context c;
    ArrayList<Article> articles;

    public CustomAdapter(Context c, ArrayList<Article> articles) {
        this.c = c;
        this.articles = articles;
    }

    @Override
    public int getCount() {
        return articles.size();
    }

    @Override
    public Object getItem(int position) {
        return articles.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if(convertView==null)
        {
            convertView= LayoutInflater.from(c).inflate(R.layout.model,parent,false);
        }

        TextView titleTxt= (TextView) convertView.findViewById(R.id.titleTxt);
        TextView descTxt= (TextView) convertView.findViewById(R.id.descTxt);
        TextView dateTxt= (TextView) convertView.findViewById(R.id.dateTxt);
        ImageView img= (ImageView) convertView.findViewById(R.id.articleImage);

        Article article= (Article) this.getItem(position);

        final String title=article.getTitle();
        String desc=article.getDescription();
        String date=article.getDate();
        String imageUrl=article.getImageUrl().replace("localhost","10.0.2.2");

        titleTxt.setText(title);
        descTxt.setText(desc.substring(0,130));
        dateTxt.setText(date);
        PicassoClient.downloadImage(c, imageUrl, img);

        convertView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(c,title,Toast.LENGTH_SHORT).show();
            }
        });

        return convertView;
    }
}

Picasso Client class.

Main Responsibility : DOWNLOAD OUR IMAGES AND CACHE THEM.

• Picasso library shall help us download images when supplied with a URL.

package com.tutorials.hp.listviewrssimagestext.m_UI;

import android.content.Context;
import android.widget.ImageView;

import com.squareup.picasso.Picasso;
import com.tutorials.hp.listviewrssimagestext.R;

public class PicassoClient {

    public static void downloadImage(Context c,String imageUrl,ImageView img)
    {
        if(imageUrl != null && imageUrl.length()>0)
        {
            Picasso.with(c).load(imageUrl).placeholder(R.drawable.placeholder).into(img);
        }else {
            Picasso.with(c).load(R.drawable.placeholder).into(img);
        }
    }
}

SECTION 4 : Our Activity

MainActivity class.

Main Responsibility : LAUNCH OUR APP.

• We shall reference the views like ListView and Floating action button here,from our XML Layouts.
• We then execute our Downloader class when Floating action button is clicked.
• We shall also define here our feeds url and parse the data.

package com.tutorials.hp.listviewrssimagestext;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListView;

import com.tutorials.hp.listviewrssimagestext.m_RSS.Downloader;

public class MainActivity extends AppCompatActivity {

    final static String urlAddress="http://10.0.2.2/galacticnews/index.php/feed";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);

        final ListView lv= (ListView) findViewById(R.id.lv);

        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                new Downloader(MainActivity.this,urlAddress,lv).execute();
            }
        });
    }

}

SECTION 5 : Our Layouts

ActivityMain.xml Layout.

• Inflated as our activity’s view.
• Includes our content main.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
    
    
    android_layout_width="match_parent"
    android_layout_height="match_parent"
    android_fitsSystemWindows="true"
    tools_context="com.tutorials.hp.listviewrssimagestext.MainActivity">

    <android.support.design.widget.AppBarLayout
        android_layout_width="match_parent"
        android_layout_height="wrap_content"
        android_theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android_id="@+id/toolbar"
            android_layout_width="match_parent"
            android_layout_height="?attr/actionBarSize"
            android_background="?attr/colorPrimary"
            app_popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

    <include layout="@layout/content_main" />

    <android.support.design.widget.FloatingActionButton
        android_id="@+id/fab"
        android_layout_width="wrap_content"
        android_layout_height="wrap_content"
        android_layout_gravity="bottom|end"
        android_layout_margin="@dimen/fab_margin"
        android_src="@android:drawable/ic_dialog_email" />

</android.support.design.widget.CoordinatorLayout>

ContentMain.xml Layout.

• Defines our view hierarchy.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
    
    
    android_layout_width="match_parent"
    android_layout_height="match_parent"
    android_paddingBottom="@dimen/activity_vertical_margin"
    android_paddingLeft="@dimen/activity_horizontal_margin"
    android_paddingRight="@dimen/activity_horizontal_margin"
    android_paddingTop="@dimen/activity_vertical_margin"
    app_layout_behavior="@string/appbar_scrolling_view_behavior"
    tools_context="com.tutorials.hp.listviewrssimagestext.MainActivity"
    tools_showIn="@layout/activity_main">

    <ListView
        android_id="@+id/lv"
        android_layout_width="match_parent"
        android_layout_height="wrap_content"
         />
</RelativeLayout>

Model.xml Layout.

• Inflated as our AdapterView’s viewitems.

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView 
    android_orientation="horizontal" android_layout_width="match_parent"
    
    android_layout_margin="10dp"
    card_view_cardCornerRadius="5dp"
    card_view_cardElevation="5dp"
    android_layout_height="200dp">

    <LinearLayout
        android_orientation="horizontal"
        android_layout_width="match_parent"
        android_layout_height="match_parent">
        <ImageView
            android_layout_width="100dp"
            android_layout_height="wrap_content"
            android_id="@+id/articleImage"
            android_padding="10dp"
            android_src="@drawable/placeholder" />

        <LinearLayout
            android_orientation="vertical"
            android_layout_width="match_parent"
            android_layout_height="match_parent">

            <TextView
                android_layout_width="match_parent"
                android_layout_height="wrap_content"
                android_textAppearance="?android:attr/textAppearanceLarge"
                android_text="Title"
                android_id="@+id/titleTxt"
                android_padding="10dp"
                android_textColor="@color/colorAccent"
                android_textStyle="bold"
                android_layout_alignParentLeft="true"
                />

            <TextView
                android_layout_width="wrap_content"
                android_layout_height="wrap_content"
                android_textAppearance="?android:attr/textAppearanceLarge"
                android_text="Description....................."
                android_lines="3"
                android_id="@+id/descTxt"
                android_padding="10dp"

                android_layout_alignParentLeft="true"
                />

            <TextView
                android_layout_width="wrap_content"
                android_layout_height="wrap_content"
                android_textAppearance="?android:attr/textAppearanceMedium"
                android_text="Date"
                android_textStyle="italic"
                android_id="@+id/dateTxt" />

        </LinearLayout>
    </LinearLayout>

</android.support.v7.widget.CardView>

LAST SECTION

• Lets share more tips in OUR FB PAGE.
• To see the XML  we were parsing and the website itself please have look at the tutorial at our youtbe channel : ProgramminWizards.
• You’ll also find the demo for this example and step by step explanations.

Cheers.