Store JSON Array from NewsAPI in Firebase - arrays

Question

I have used volley to parse news data from the newsAPI.org. I want to save the response to Firebase for offline viewing and persistence.
This is the sample response from API:
articles: [
{
author: "Megan Rose Dickey",
title: "Ojo wants to be the electric scooter for commuters, but...",
description: "Commuting in a busy city like San Francisco can be
annoying..",
url: "https://techcrunch.com/2017/08/23/ojo-wants-to-be-the-electric-
scooter-for-commuters-but-its-not-there-yet/",
urlToImage: "https://img.vidible.tv/prod/2017",
publishedAt: "2017-08-23T21:19:56Z"
},
{
author: "Katie Roof",
title: "Pishevar intervenes in Benchmark-Kalanick lawsuit",
description: "Early Uber investor and former board member Shervin
Pishevar is speaking out against Benchmark again..",
url: "https://techcrunch.com/2017/08/24/pishevar-sends-another-letter-
to-uber-board-about-benchmark/",
urlToImage:"https://tctechcrunch2011.files.wordpress.com/",
publishedAt: "2017-08-24T22:49:59Z"
},
In total I have 5 objects inside the articles array.
I want to store each of the objects in Firebase database. This is what I have tried:
StringRequest stringRequest = new StringRequest(Request.Method.GET, Constants.NEWS_ENDPOINT,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
if (response != null){
Log.d(TAG, "News Api Response is: \t" + response.toString());
try {
JSONObject jsonObject = new JSONObject(response);
JSONArray articles = jsonObject.getJSONArray("articles");
for (int i = 0; i < articles.length(); i++){
JSONObject items = articles.getJSONObject(i);
final String title_news = items.getString("title");
final String desc_news = items.getString("description");
final String urlImg = items.getString("urlToImage");
final String author_news = items.getString("author");
final String url = items.getString("url");
final String publishedAt = items.getString("publishedAt");
NewsItem newsItem = new NewsItem(author_news, title_news, desc_news, url, urlImg, publishedAt);
itemList.add(newsItem);
/**
* Save JSON Results to Firebase
* */
for (int k = 0; k < articles.length(); k++){
HashMap hashMap = new HashMap();
hashMap.put("newsTitle", title_news);
hashMap.put("newsDesc", desc_news);
hashMap.put("newsImageUrl", urlImg);
hashMap.put("newsAuthor", author_news);
hashMap.put("newsUrl", url);
hashMap.put("newsDate", publishedAt);
newsRootRef.setValue(hashMap);
}
When I check the console, it saves only one object, the last object like this:
I want to store all objects AS-IS in the response array and retrieve them later. Is there another way to do this? Thanks, sorry for the long post.

Answer 1

In this case you need to use push() to store the data. Otherwise you are just replacing the data at the reference at each iteration. This is why it seems that only the last record gets stored. Try to change this line:
newsRootRef.setValue(hashMap);
...into this:
newsRootRef.push().setValue(hashMap);
To avoid duplicating entries I recommend that you fetch all entries from Firebase and cache the url property (since this property seems to be unique) in a HashSet. Then you can modify your code like this:
if (!urlSet.contains(url)) {
HashMap hashMap = new HashMap();
hashMap.put("newsTitle", title_news);
hashMap.put("newsDesc", desc_news);
hashMap.put("newsImageUrl", urlImg);
hashMap.put("newsAuthor", author_news);
hashMap.put("newsUrl", url);
hashMap.put("newsDate", publishedAt);
newsRootRef.push(),setValue(hashMap);
}
But of course you need to populate your HashSet first so I'd recommend doing something like this:
final Set<String> urlSet = new HashSet<>();
newsRootRef.addChildEventListener(new ChildEventListener() {
int i = 0;
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
urlSet.add(dataSnapshot.getValue(String.class));
if (i++ == dataSnapshot.getChildrenCount()) {
...
...your code...
StringRequest stringRequest = new StringRequest(Request.Method.GET, Constants.NEWS_ENDPOINT,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
...
...
}
}
#Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
#Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});