I've got some informations that I get from a nutrition database.I'm new to android studio and my question is, how can I access the data while being offline using Firebase? I don't know where to start, I want to display the list that I get while being offline.Any advices would help me. This is the list that I get:
Java code that I use to parse the url:
package com.example.myapplication;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.MenuItem;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
public class NutritionPlan2 extends AppCompatActivity {
private String TAG = MainActivity.class.getSimpleName();
private ListView lv;
ArrayList<HashMap<String, String>> resultList;
@Override
public boolean onOptionsItemSelected(MenuItem item) {
super.onOptionsItemSelected(item);
switch (item.getItemId()) {
case android.R.id.home:
finish();
break;
}
return true;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_nutrition_plan2);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
if (getSupportActionBar() != null){
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);
}
resultList = new ArrayList<>();
lv = (ListView) findViewById(R.id.list);
new GetContacts().execute();
}
private class GetContacts extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
Toast.makeText(NutritionPlan2.this,"Json Data is downloading",Toast.LENGTH_LONG).show();
}
@Override
protected Void doInBackground(Void... arg0) {
HttpHandler sh = new HttpHandler();
// Making a request to url and getting response
String url = "https://api.spoonacular.com/recipes/complexSearch?diet=vegan&addRecipeNutrition=true&apiKey=d22842b0ca9148839497a0022902ae97";
String jsonStr = sh.makeServiceCall(url);
Log.e(TAG, "Response from url: " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
JSONArray results = jsonObj.getJSONArray("results");
// looping through All items
for (int i = 0; i < results.length(); i++) {
JSONObject c = results.getJSONObject(i);
String title = c.getString("title");
String healthScore = c.getString("healthScore");
String servings = c.getString("servings");
String pricePerServing = c.getString("pricePerServing");
String readyInMinutes = c.getString("readyInMinutes");
// tmp hash map for single contact
HashMap<String, String> result = new HashMap<>();
// adding each child node to HashMap key => value
result.put("title",title);
result.put("pricePerServing","Cost: " + pricePerServing);
result.put("servings","Servings: " + servings);
result.put("healthScore","Health Score: " +healthScore);
result.put("readyInMinutes","Time to cook: " +readyInMinutes +"minutes");
// adding contact to contact list
resultList.add(result);
//
}
} catch (final JSONException e) {
Log.e(TAG, "Json parsing error: " + e.getMessage());
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Json parsing error: " + e.getMessage(),Toast.LENGTH_LONG).show();
}
});
}
} else {
Log.e(TAG, "Couldn't get json from server.");
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Couldn't get json from server. Check LogCat for possible errors!",
Toast.LENGTH_LONG).show();
}
});
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
ListAdapter adapter = new SimpleAdapter(NutritionPlan2.this, resultList,
R.layout.list_nutrition_plans, new String[]{ "title","pricePerServing","servings","healthScore","readyInMinutes"},
new int[]{R.id.title, R.id.pricePerServing,R.id.servings,R.id.healthscore,R.id.readyInMinutes});
lv.setAdapter(adapter);
}
}
}
This is the list adapter:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="@dimen/activity_horizontal_margin">
<TextView
android:id="@+id/title"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="@color/colorAccent"
android:text="Title:"/>
<TextView
android:id="@+id/healthscore"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingTop="5dp"
android:textColor="@color/black"
android:text="Health Score:"/>
<TextView
android:id="@+id/pricePerServing"
android:layout_width="fill_parent"
android:paddingTop="5dp"
android:layout_height="wrap_content"
android:textColor="@color/black"
android:text="pricePerServing:"/>
<TextView
android:id="@+id/servings"
android:layout_width="fill_parent"
android:paddingTop="5dp"
android:layout_height="wrap_content"
android:textColor="@color/black"
android:text="Servings:"/>
<TextView
android:id="@+id/readyInMinutes"
android:layout_width="fill_parent"
android:paddingTop="5dp"
android:layout_height="wrap_content"
android:textColor="@color/black"
android:text="readyInMinutes:"/>
</LinearLayout>