Networking is an integral part of android development, especially when building data-driven clients. The java class mainly used for network connections is HttpUrlConnection. The class requires manual management of data parsing and asynchronous execution of requests. For network operations, we are better off using a library called Fast Android Networking Library which can take care of sending and parsing network requests. In this article, we will step through the process of building an android news application. Fast Android Networking Library supports all types of HTTP/HTTPS requests and in our app, we will use it for
- Performing GET requests
- Loading images from the internet into ImageViews
Here is what the application will look like in the end:
Step By Step Implementation
Step 1: Create a New Project
To learn how to create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio and choose java as the programming language.
Step 2: Add dependencies
Select Gradle Scripts > build.gradle(Module:app) and add the below dependency in the dependencies section.
implementation 'com.amitshekhar.android:android-networking:1.0.2' implementation 'com.amitshekhar.android:jackson-android-networking:1.0.2'
After adding the dependencies, sync your project by clicking Sync Now.
Step 3: Add permissions
Select manifests > AndroidManifest.xml and add the internet permission above the application tag.
<uses-permission android:name="android.permission.INTERNET" />
Step 4: Get an API Key
Visit newsapi and register. The key will be displayed after registration and also sent to your email inbox.
Step 5: Create a new empty activity and add a WebView to the layout
Go to app > java > right-click > New > Activity > Empty Activity and name it as WebActivity. This activity will display web pages of articles as part of the activity layout. To add a WebView to the activity_web.xml file. Navigate to app > res > layout > activity_web.xml and add the below code to that file.
<? xml version = "1.0" encoding = "utf-8" ?>
< LinearLayout
android:layout_width = "match_parent"
android:layout_height = "match_parent"
tools:context = ".WebActivity" >
<!-- webview to display web pages
as part of the activity -->
< WebView
android:id = "@+id/webview"
android:layout_width = "match_parent"
android:layout_height = "match_parent" />
</ LinearLayout >
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Step 6: Working with the WebActivity.java file
Below is the code for WebActivity.java.
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.webkit.WebView;
public class WebActivity extends AppCompatActivity {
// setting the TAG for debugging purposes
private static String TAG= "WebActivity" ;
// declaring the webview
private WebView myWebView;
// declaring the url string variable
private String url;
@Override
protected void onCreate(Bundle savedInstanceState) {
super .onCreate(savedInstanceState);
setContentView(R.layout.activity_web);
// assigning the views to id's
myWebView = (WebView) findViewById(R.id.webview);
Intent intent = getIntent();
// checking if there is an intent
if (intent!= null ){
// retrieving the url in the intent
url = intent.getStringExtra( "url_key" );
// loading and displaying a
// web page in the activity
myWebView.loadUrl(url);
}
}
@Override
protected void onRestart() {
super .onRestart();
finish();
}
} |
Step 7: Add a RecyclerView to the activity_main.xml file
Select app > res > layout > activity_main.xml and add the below code to that file. The RecyclerView is used to efficiently display a list of data and in our case, it will display a list of news articles.
<? xml version = "1.0" encoding = "utf-8" ?>
< RelativeLayout
android:layout_width = "match_parent"
android:layout_height = "match_parent"
tools:context = ".MainActivity" >
<!-- A RecyclerView to efficiently
display a list of articles -->
< androidx.recyclerview.widget.RecyclerView
android:id = "@+id/recyclerview_id"
android:layout_width = "match_parent"
android:layout_height = "match_parent" >
</ androidx.recyclerview.widget.RecyclerView >
<!-- loading spinner to be displayed
while the library fetches news -->
< ProgressBar
android:id = "@+id/progressbar_id"
android:layout_width = "wrap_content"
android:indeterminateTint = "#0F9D58"
android:layout_centerHorizontal = "true"
android:layout_centerVertical = "true"
android:layout_height = "wrap_content" >
</ ProgressBar >
</ RelativeLayout >
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Step 8: Create a new custom layout
Navigate to File > New > XML > Layout XML File and name it as article_item. The article_item.xml file will be used for each row within the news article list. Below is the code for the article_item.xml file.
<? xml version = "1.0" encoding = "utf-8" ?>
android:layout_width = "match_parent"
android:orientation = "vertical"
android:layout_height = "wrap_content" >
<!-- horizontal LinearLayout containing
image and article details -->
< LinearLayout
android:layout_width = "match_parent"
android:gravity = "center"
android:weightSum = "10"
android:orientation = "horizontal"
android:layout_height = "wrap_content" >
<!-- Image of news thumbnail -->
<!-- ANImageView is a view provided by
Fast Android Networking Library -->
< com.androidnetworking.widget.ANImageView
android:id = "@+id/image_id"
android:layout_weight = "3"
android:layout_width = "0dp"
android:layout_height = "wrap_content" />
< LinearLayout
android:layout_weight = "7"
android:layout_width = "0dp"
android:layout_height = "wrap_content"
android:padding = "10dp"
android:orientation = "vertical" >
<!-- Text with title -->
< TextView
android:id = "@+id/title_id"
android:layout_width = "wrap_content"
android:layout_height = "wrap_content"
android:ellipsize = "end"
android:maxLines = "2"
android:textStyle = "bold"
android:textColor = "#0F9D58"
android:textSize = "14sp" />
<!-- Text with description name -->
< TextView
android:id = "@+id/description_id"
android:layout_marginTop = "2dp"
android:layout_width = "wrap_content"
android:layout_height = "wrap_content"
android:ellipsize = "end"
android:fontFamily = "sans-serif-medium"
android:textAllCaps = "false"
android:textSize = "12sp" />
</ LinearLayout >
</ LinearLayout >
<!-- Text with author name and date -->
< TextView
android:id = "@+id/contributordate_id"
android:layout_marginTop = "1dp"
android:layout_width = "wrap_content"
android:layout_height = "wrap_content"
android:ellipsize = "end"
android:maxLines = "1"
android:textSize = "12sp" />
<!-- View showing thin green horizontal
line separating articles -->
< View
android:layout_width = "match_parent"
android:layout_marginTop = "3dp"
android:layout_marginBottom = "5dp"
android:layout_height = "0.2dp"
android:background = "#0F9D58" />
</ LinearLayout >
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Step 9: Create a NewsArticle Model class
Navigate to app > Java > package > Right Click on package> New > Java Class and name it as NewsArticle. We created this model class for storing news article data like title, content, description e.t.c.
In our model class, there are mainly three types of methods :
- Constructors: initializes newly created NewsArticle objects
- Get methods: for getting property values
- Set methods: for setting property values
Below is the code for the NewsArticle.java file.
public class NewsArticle {
// the properties/attributes
// of the ArticleModel
String author;
String title;
String description;
String url;
String urlToImage;
String publishedAt;
String content;
// ArticleModel empty constructor
public NewsArticle() {
}
// get method : returns the name of the author
public String getAuthor() {
return author;
}
// set method : sets the author
public void setAuthor(String author) {
this .author = author;
}
// get method : returns the title of the article
public String getTitle() {
return title;
}
// set method : sets the title
public void setTitle(String title) {
this .title = title;
}
// get method : returns the description of the article
public String getDescription() {
return description;
}
// set method : sets the description
public void setDescription(String description) {
this .description = description;
}
// get method : returns url of the article
public String getUrl() {
return url;
}
// set method : sets the url of the article
public void setUrl(String url) {
this .url = url;
}
// get method : returns the urlToImage of the article
public String getUrlToImage() {
return urlToImage;
}
// set method : sets the UrlToImage
public void setUrlToImage(String urlToImage) {
this .urlToImage = urlToImage;
}
// get method : returns the date
public String getPublishedAt() {
return publishedAt;
}
// set method : sets the date
public void setPublishedAt(String publishedAt) {
this .publishedAt = publishedAt;
}
// get method : returns the content of the article
public String getContent() {
return content;
}
// set method : sets the title
public void setContent(String content) {
this .content = content;
}
} |
Step 10: Create an ArticleAdapter class
Navigate to app > Java > package > Right Click on package> New > Java Class and name it as ArticleAdapter.The ArticleAdapter class is responsible for getting data from the NewsArticle model and displaying it on view. The adapter will provide access to the data items and is answerable for creating a view for each news article in the data set. Below is the code for the ArticleAdapter.java file.
import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import com.androidnetworking.widget.ANImageView;
import java.util.ArrayList;
public class ArticleAdapter extends RecyclerView.Adapter<ArticleAdapter.ViewHolder> {
// setting the TAG for debugging purposes
private static String TAG= "ArticleAdapter" ;
private ArrayList<NewsArticle> mArrayList;
private Context mContext;
public ArticleAdapter(Context context,ArrayList<NewsArticle> list){
// initializing the constructor
this .mContext=context;
this .mArrayList=list;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder( @NonNull ViewGroup parent, int viewType) {
// inflating the layout with the article view (R.layout.article_item)
View view=LayoutInflater.from(mContext).inflate(R.layout.article_item,parent, false );
return new ViewHolder(view);
}
@Override
public void onBindViewHolder( @NonNull ViewHolder holder, int position) {
// the parameter position is the index of the current article
// getting the current article from the ArrayList using the position
NewsArticle currentArticle=mArrayList.get(position);
// setting the text of textViews
holder.title.setText(currentArticle.getTitle());
holder.description.setText(currentArticle.getDescription());
// subString(0,10) trims the date to make it short
holder.contributordate.setText(currentArticle.getAuthor()+
" | " +currentArticle.getPublishedAt().substring( 0 , 10 ));
// Loading image from network into
// Fast Android Networking View ANImageView
holder.image.setDefaultImageResId(R.drawable.ic_launcher_background);
holder.image.setErrorImageResId(R.drawable.ic_launcher_foreground);
holder.image.setImageUrl(currentArticle.getUrlToImage());
// setting the content Description on the Image
holder.image.setContentDescription(currentArticle.getContent());
// handling click event of the article
holder.itemView.setOnClickListener( new View.OnClickListener() {
@Override
public void onClick(View view) {
// an intent to the WebActivity that display web pages
Intent intent = new Intent(mContext, WebActivity. class );
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.putExtra( "url_key" ,currentArticle.getUrl());
// starting an Activity to display the page of the article
mContext.startActivity(intent);
}
});
}
@Override
public int getItemCount() {
return mArrayList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
// declaring the views
private TextView title,description,contributordate;
private ANImageView image;
public ViewHolder( @NonNull View itemView) {
super (itemView);
// assigning views to their ids
title=itemView.findViewById(R.id.title_id);
description=itemView.findViewById(R.id.description_id);
image=itemView.findViewById(R.id.image_id);
contributordate=itemView.findViewById(R.id.contributordate_id);
}
}
} |
Step 11: Working with the MainActivity.java file
In our activity, we will make GET requests to the news API using Android Fast Library and populate the RecyclerView with news articles. Firstly, we will create a string variable and set it to the API key (the key we created in step 4). For example if your API key = b971358de21d4af48ae24b5faf06bbok. Then declare the variable as :
private static String API_KEY="b971358de21d4af48ae24b5faf06bbok";
Below is the code for the MainActivity.java file.
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ProgressBar;
import com.androidnetworking.AndroidNetworking;
import com.androidnetworking.common.Priority;
import com.androidnetworking.error.ANError;
import com.androidnetworking.interfaces.JSONObjectRequestListener;
import com.jacksonandroidnetworking.JacksonParserFactory;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
// TODO : set the API_KEY variable to your api key
private static String API_KEY= "" ;
// setting the TAG for debugging purposes
private static String TAG= "MainActivity" ;
// declaring the views
private ProgressBar mProgressBar;
private RecyclerView mRecyclerView;
// declaring an ArrayList of articles
private ArrayList<NewsArticle> mArticleList;
private ArticleAdapter mArticleAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super .onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// initializing the Fast Android Networking Library
AndroidNetworking.initialize(getApplicationContext());
// setting the JacksonParserFactory
AndroidNetworking.setParserFactory( new JacksonParserFactory());
// assigning views to their ids
mProgressBar=(ProgressBar)findViewById(R.id.progressbar_id);
mRecyclerView=(RecyclerView)findViewById(R.id.recyclerview_id);
// setting the recyclerview layout manager
mRecyclerView.setLayoutManager( new LinearLayoutManager( this ));
// initializing the ArrayList of articles
mArticleList= new ArrayList<>();
// calling get_news_from_api()
get_news_from_api();
}
public void get_news_from_api(){
// clearing the articles list before adding news ones
mArticleList.clear();
// Making a GET Request using Fast
// Android Networking Library
// the request returns a JSONObject containing
// news articles from the news api
// or it will return an error
.addQueryParameter( "country" , "in" )
.addQueryParameter( "apiKey" ,API_KEY)
.addHeaders( "token" , "1234" )
.setTag( "test" )
.setPriority(Priority.LOW)
.build()
.getAsJSONObject( new JSONObjectRequestListener(){
@Override
public void onResponse(JSONObject response) {
// disabling the progress bar
mProgressBar.setVisibility(View.GONE);
// handling the response
try {
// storing the response in a JSONArray
JSONArray articles=response.getJSONArray( "articles" );
// looping through all the articles
// to access them individually
for ( int j= 0 ;j<articles.length();j++)
{
// accessing each article object in the JSONArray
JSONObject article=articles.getJSONObject(j);
// initializing an empty ArticleModel
NewsArticle currentArticle= new NewsArticle();
// storing values of the article object properties
String author=article.getString( "author" );
String title=article.getString( "title" );
String description=article.getString( "description" );
String url=article.getString( "url" );
String urlToImage=article.getString( "urlToImage" );
String publishedAt=article.getString( "publishedAt" );
String content=article.getString( "content" );
// setting the values of the ArticleModel
// using the set methods
currentArticle.setAuthor(author);
currentArticle.setTitle(title);
currentArticle.setDescription(description);
currentArticle.setUrl(url);
currentArticle.setUrlToImage(urlToImage);
currentArticle.setPublishedAt(publishedAt);
currentArticle.setContent(content);
// adding an article to the articles List
mArticleList.add(currentArticle);
}
// setting the adapter
mArticleAdapter= new ArticleAdapter(getApplicationContext(),mArticleList);
mRecyclerView.setAdapter(mArticleAdapter);
} catch (JSONException e) {
e.printStackTrace();
// logging the JSONException LogCat
Log.d(TAG, "Error : " +e.getMessage());
}
}
@Override
public void onError(ANError error) {
// logging the error detail and response to LogCat
Log.d(TAG, "Error detail : " +error.getErrorDetail());
Log.d(TAG, "Error response : " +error.getResponse());
}
});
}
} |
Output: