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How to parse array inside json object in android java?

how to display array data in json object if the json data is like below. I want to display array data of Ingredient and step. This is the full API Address that I want to fetch the data https://masak-apa-tomorisakura.vercel.app/api/recipe/resep-nasi-bakar-ayam
I've tried several ways but I can't find how to implement it properly.
this is my json model.
#SerializedName("ingredient")
#Expose
Ingredient ingredient = null;
public Ingredient getIngredient() {
return ingredient;
}
public void setIngredient(Ingredient ingredient) {
this.ingredient = ingredient;
}
This is the code I use to display the data
public void LoadData() {
Call<ResultsResponse> call = Config.getInstance().getApi().results(kunci);
call.enqueue(new Callback<ResultsResponse>() {
#Override
public void onResponse(Call<ResultsResponse> call, Response<ResultsResponse> response) {
shimmerFrameLayout.startShimmer();
detailJudul.setText(response.body().getResults().getTitle());
detailWaktu.setText(response.body().getResults().getTimes());
detailKesulitan.setText(response.body().getResults().getDificulty());
detailPorsi.setText(response.body().getResults().getServings());
detailDeskripsi.setText(response.body().getResults().getIngredient());
detailAuthor.setText(response.body().getResults().getAuthor().getUser());
Glide.with(DetailResepActivity.this)
.load(response.body().getResults().getThumb())
.apply(new RequestOptions().override(400, 400))
.into(detailGambar);
//Intent Baca Resep di browser
llVisitWeb.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String url = ("https://www.masakapahariini.com/resep/" + kunci);
Intent i = new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);
}
});
shimmerFrameLayout.setVisibility(View.GONE);
}
#Override
public void onFailure(Call<ResultsResponse> call, Throwable t) {
Log.d("Hasil", t.getMessage());
}
});
//Intent kembali ke MainActivity
RelativeLayout ivBack=findViewById(R.id.back);
ivBack.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(v.getContext(), MainActivity.class);
startActivity(i);
}
});
}
This is the error that android studio shows
Thanks, I hope someone gives an example project that displays array data in a json object like my problem above.
UPDATE
Thanks Gralls, I can display the array data by creating a new string and implementing
String ingredient= response.body().getResults().getIngredient().toString();
detailDeskripsi.setText(ingredient);
it into the previously created string. Then how to make the data ingredient can be in the form of a list?

I don't have an example project but ingredients is array of strings. So instead of having
#SerializedName("ingredient")
#Expose
Ingredient ingredient = null;
you should parse array into some sort of the list
#SerializedName("ingredient")
List<String> ingredient = null;
I hope that this will help :)

How to pass entire Arraylist to another activity

I am making a mp3 player app , in my main activity I am showing the list of all songs in recycler view and when user click on the song I am trying to send entire array list of songs to my player activity , where I can work for with next and previous songs play , but my app crashes when click the song
Process: com.choudhary.musicplayer, PID: 8686
java.lang.RuntimeException: Parcel: unable to marshal value com.choudhary.musicplayer.AudioModel#a0de380
at android.os.Parcel.writeValue(Parcel.java:1667)
at android.os.Parcel.writeList(Parcel.java:966)
at android.os.Parcel.writeValue(Parcel.java:1614)
at android.os.Parcel.writeArrayMapInternal(Parcel.java:878)
at android.os.BaseBundle.writeToParcelInner(BaseBundle.java:1588)
at android.os.Bundle.writeToParcel(Bundle.java:1233)
at android.os.Parcel.writeBundle(Parcel.java:918)
at android.content.Intent.writeToParcel(Intent.java:9987)
at android.app.IActivityManager$Stub$Proxy.startActivity(IActivityManager.java:3636)
at android.app.Instrumentation.execStartActivity(Instrumentation.java:1675)
at android.app.Activity.startActivityForResult(Activity.java:4651)
at androidx.activity.ComponentActivity.startActivityForResult(ComponentActivity.java:597)
at android.app.Activity.startActivityForResult(Activity.java:4609)
at androidx.activity.ComponentActivity.startActivityForResult(ComponentActivity.java:583)
at android.app.Activity.startActivity(Activity.java:4970)
at android.app.Activity.startActivity(Activity.java:4938)
at com.choudhary.musicplayer.MusicAdapter$1.onClick(MusicAdapter.java:54)
at android.view.View.performClick(View.java:6608)
at android.view.View.performClickInternal(View.java:6585)
at android.view.View.access$3100(View.java:785)
at android.view.View$PerformClick.run(View.java:25921)
My Adapter's OnBind method :--
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
holder.name.setText(arrayList.get(position).getaName());
holder.album.setText(arrayList.get(position).getaAlbum());
holder.imageView.setImageBitmap(BitmapFactory.decodeFile(arrayList.get(position).getAlbumart()));
holder.imageView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent in = new Intent(context,PlayerActivity.class);
in.putExtra("SONG",arrayList.get(position).getaName());
in.putExtra("PATH",arrayList.get(position).getaPath());
in.putExtra("ALBUM",arrayList.get(position).getaAlbum());
in.putExtra("LIST",arrayList);
in.putExtra("POSITION", arrayList.get(position).toString());
context.startActivity(in);
}
});
}
my Player Activity :---
public class PlayerActivity extends AppCompatActivity {
TextView songanme, songAlbum,duration,movetime;
ImageView playbutton,nextbtn,previousbtn;
SeekBar seekBar;
MediaPlayer mediaPlayer ;
ArrayList<AudioModel> list;
int CURRENT_POSITION ;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_player);
songanme = findViewById(R.id.music_name_pl);
movetime = findViewById(R.id.move_time);
seekBar = findViewById(R.id.seekBar);
songAlbum = findViewById(R.id.music_album_pl);
duration = findViewById(R.id.duration);
playbutton = findViewById(R.id.play_btn_pl);
nextbtn = findViewById(R.id.next_btn_pl);
previousbtn = findViewById(R.id.previous_pl);
list = new ArrayList<>();
songanme.setSelected(true);
Intent intent = getIntent();
Bundle bundle = intent.getExtras();
list = (ArrayList) bundle.getParcelableArrayList("LIST");
}

Let's assume that you want to pass an ArrayList of the Song class from Activity1 to Activity2.
1- The Song class should implement the Serializable class.
It would be something like that..
import java.io.Serializable;
public class Song implements Serializable {
String name;
String album;
public Song(String name, String album) {
this.name = name;
this.album = album;
}
}
2-In Activity1 pass your array list object as an extra to Ativity2
ArrayList<Song> songs= new ArrayList();
songs.add(new Song("song1","album1"));
songs.add(new Song("song2","album2"));
songs.add(new Song("song3","album3"));
Intent intent=new Intent(this,Activity2.class);
intent.putExtra("songs",songs);
startActivity(intent);
3- Finally receive the array list with getSerializableExtra in Activity2
ArrayList<Song> songs = (ArrayList<Song>) getIntent().getSerializableExtra("songs");
Log.i("HINT", "" + songs.size());

You can create a singleton class for sharing your ArrayList across various components of android. Sample code for the singleton class is described below-
public class SongBank
{
private static SongBank instance;
private ArrayList<Song> songsArrayList;
private SongBank(Context context)
{
// You can do any stuff if you want here
}
// create getter and setter methods for your arrayList
public void setSongsList(ArrayList<Song> songs)
{
if(songs!=null)
{
this.songsArrayList=songs;
}
}
public ArrayList<Song> getSongsList()
{
return this.songsArrayList;
}
public static SongBank getInstance(Context context)
{
if(instance==null)
{
instance=new SongBank(context);
}
return instance;
}
}
The instance of this singleton class can be called across various activities or fragments and you can also change the Arraylist value across different activities if you want. You can also call this class and get the list in your music service without worrying about serialization.

Losing data when sending between two classes

My app doesn't display anything when passing data from one class to another. I located through with the debugger that my ArrayList doesn't get the right value from the class.
I'm sending data with the following function:
public class Adaugare extends AppCompatActivity {
private ListView myListView;
private NumeAdapter numeAdapter;
String inume;
int ivarsta;
Intent intent = new Intent();
private ArrayList persoanaArrayList = new ArrayList<>();
public ArrayList getPersoanaArrayList() {
return persoanaArrayList;
}
public int getPersoanaArrayListsize() {
return persoanaArrayList.size();
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_adaugare);
myListView = (ListView) findViewById(R.id.persoana_list);
Button btn_fin = (Button) findViewById(R.id.btn_fin);
btn_fin.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
EditText nume_edit_text = (EditText) findViewById(R.id.ins_nume);
EditText varsta_edit_text = (EditText) findViewById(R.id.ins_var);
ivarsta = Integer.parseInt(varsta_edit_text.getText().toString());
inume = nume_edit_text.getText().toString();
persoanaArrayList.add(new Persoana(inume, ivarsta));
}
});
}
}
And recieving it with:
public class Afisare extends AppCompatActivity {
ListView myListView;
NumeAdapter numeAdapter;
Adaugare ad = new Adaugare();
int cate;
int i;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_afisare);
myListView = (ListView) findViewById(R.id.persoana_list);
ArrayList<Persoana> persoanaArrayList = new ArrayList<Persoana>(ad.getPersoanaArrayList());
numeAdapter = new NumeAdapter(this, persoanaArrayList);
myListView.setAdapter(numeAdapter);
}
The class Persoana is:
public class Persoana {
private String nume;
private int varsta;
Persoana(String inume, int ivar) {
this.nume = inume;
this.varsta = ivar;
}
public String getNume() {
return nume;
}
public int getVarsta() {
return varsta;
}
public void setNume(String nume) {
this.nume = nume;
}
public void setVarsta(int varsta) {
this.varsta = varsta;
}
}
Persoana is the main class, everything is saved in it. ad is an object of Adaugare, Adaugare being the class from which I've taken the code for getPersoanaArrayList. At debugging some values appeared at ad, namely Adaugare #4556, and persoanaArrayList remains null.
I need the persoanaArrayList so that i can initialize my Adapter and listView. Everything else in the code seems fine from step by step testing with debugger.

Your problem is with the following line in the Afisare class:
Adaugare ad = new Adaugare();
You can't simply new one activity from another activity and expect to access a shared list between them. To share instance data between java objects you need a reference to the other object. Creating a new instance will create a new empty list. That's why you are "losing" data. A quick fix would be to make the list static so it can be accessed from any instance.
But since you're dealing with Android, the right way to share data between activities is by using intent extras. The first activity starts the second activity via an intent. The first activity places the desired data in the intent as extras. The second activity uses getIntent() and the various methods on Intent to access the extras.
One last tip, in Android, you never use the new operator with Activities. Activities are created by the system to service an intent. If you find yourself using the new operator, that's a sign that you're doing something wrong.

Permanently save intent from other activity (with two values) to listview

I'm trying to save two values from an activity (where the user can put in two different values, one String value and one integer value) in the listview from another activity. In the first activity, it shows a list with a course and the amount of points for that course in one listview, like this:
Course: English
Points: 4
Now, the problem is, everytime I want to put in another value using the add_course_actitivty, it overwrites the previous value. I've looked at different solutions, like with sharedpreferences (Add items to listview from other activity), but this uses only one value and if I try to work with sharedpreferences, it overwrites the other value in the sharedpreferences, but I want users to add multiple courses and corresponding points. Also on restart, it deletes the values in the listview (I read to prevent this you need to store it in sharedpreferences, but this doesn't work the way I need it to be)
KeuzeActivity.class (shows the listview):
public class KeuzeActivity extends AppCompatActivity {
private FloatingActionButton fab_add;
private String student_naam;
private ListView keuze_list;
boolean wantDelete;
private ArrayAdapter adapter;
private String vak;
private int ec;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_keuze);
// setting title
student_naam = getIntent().getStringExtra("student");
setTitle("Keuzevakken en projecten van " + student_naam);
//initialzing elements
fab_add = (FloatingActionButton)findViewById(R.id.fab_add);
keuze_list = (ListView) findViewById(R.id.keuze_list);
//initializing list
final ArrayList<Course> courseItems = new ArrayList<Course>();
adapter = new ArrayAdapter<Course>(this, android.R.layout.simple_list_item_1, courseItems);
keuze_list.setAdapter(adapter);
// checks if intent has required values, put it in listview
if (getIntent().hasExtra("vak") && getIntent().hasExtra("ec")) {
vak = getIntent().getStringExtra("vak");
ec = getIntent().getIntExtra("ec", ec);
courseItems.add(new Course(vak, ec));
adapter.notifyDataSetChanged();
}
// make fab go to other activity
fab_add.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(KeuzeActivity.this, add_course_activity.class));
}
});
// long press deletes item
keuze_list.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
showDeleteDialog();
if (wantDelete) {
courseItems.remove(position);
adapter.notifyDataSetChanged();
}
return true;
}
});
}
private void showDeleteDialog() {
AlertDialog.Builder infobuilder = new AlertDialog.Builder(this);
infobuilder.setCancelable(false);
infobuilder.setTitle("Vak/project verwijderen");
infobuilder.setMessage("Weet je zeker dat je het vak of project wilt verwijderen?");
final TextView text = new TextView(this);
// action when pressed OK
infobuilder.setPositiveButton("Ja", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
wantDelete = true;
dialog.cancel();
}
});
infobuilder.setNegativeButton("Nee", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
wantDelete = false;
dialog.cancel();
}
});
infobuilder.show();
}
}
add_course_activity.class (let's users input course and points)
public class add_course_activity extends AppCompatActivity {
private EditText course_edit;
private EditText ec_edit;
private Button save_btn;
private String student_name;
private int ec;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_course);
setTitle("Voeg vak of project toe");
final Context context = getApplicationContext();
// initializing elements
course_edit = (EditText) findViewById(R.id.edit_vak);
ec_edit = (EditText) findViewById(R.id.edit_ec);
save_btn = (Button) findViewById(R.id.save_button);
// action on savebutton
save_btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (course_edit.getText().toString().trim().length() > 0 && ec_edit.getText().toString().trim().length() > 0 ) {
ec = Integer.parseInt(ec_edit.getText().toString());
Intent goBack = new Intent(add_course_activity.this, KeuzeActivity.class);
goBack.putExtra("vak", course_edit.getText().toString());
goBack.putExtra("ec", ec);
goBack.putExtra("student", PreferenceManager.getDefaultSharedPreferences(context).getString("student_name", student_name));
startActivity(goBack);
}
else {
Toast.makeText(context, "Voer juiste informatie in!", Toast.LENGTH_SHORT).show();
}
}
});
}
}
Course.java class (getters and setters + with toString method)
public class Course {
private String vak;
private int ec;
public Course(String vak, int ec) {
this.vak = vak;
this.ec = ec;
}
public String getVak() {
return vak;
}
public void setVak(String vak) {
this.vak = vak;
}
public int getEc() {
return ec;
}
public void setEc(int ec) {
this.ec = ec;
}
#Override
public String toString() {
return ("Vak: " + vak + "\n" + "Punten: " + ec);
}
}
Note that my code isn't clean or done, but to get further I need to fix this problem.

You have several way to do it. As other replies have suggested you can use an SQLLite database and add data to a course table and retrieve data from it.
If you find Db approach to complicated/heavy
You could also use SharedPreferences what you need to do is figure a way to store a string that represent a list of course. It is not the best way to approach it but it will work.
Lets say you choose to serialize your Course object with "vac-ec"
Then you just store a serialized list of course. Example "vac1-ec1,vac2-ec2"
When you need to add a course you juste grab the previous string split it to list, append the new course to the list and re-serialize the list to a string to encode it.
Other solution could be to use Realm.

You should used SQLiteDatabase and create a table with valid attributes and insert your new values into them

Okay, now things are clearer. As answered by #Dwijraj, when storing what potentially will be a large set of data, for maximum control it is best to use SQLite.
You can read more about the different Saving Data methods here:
https://developer.android.com/training/basics/data-storage/index.html
SharedPreferences are best used to store small amounts of information, like storing the settings of an application. [Mute] for example. Or a highscore in case of a game.
A Database is a better option when it comes to storing large pieces of data that you will potentially manipulate.
Your data structure can be something like this, Courses table containing Unique_ID , Course Name, Course Level, Course summary.
A table for English for example which will contain
Exams, Scores, Duration.
There are a lot of things you can do.

Try by storing the records in SQLite, and get it when you want to show.
By this, You can have a track of all added items. And you can show the items you want.

android : can't delete and remove sharedpreferences file

i have posting question in here but i got nothing, so i decide to make a new question for searching other solution.
this is my case : First, I was using Shared preferences for my application for sending data from one activity to another, when listview is clicked in first activity, it will going to detail. when other list is clicked, it will going to first data that i've clicked before it. then i realize if i use sharedpreferences for sending data from one activity to other activity, it will save in device memory, so i change my code and decide to use intent, but my sharedpreferences's file is not remove. when list is clicked, it will going to first data that i've clicked when i use shared preferences.
I have used:
settings.edit().clear().commit();
and
settings.edit().remove().commit();
but i think it doesn't work. this is my first activity using intent:
public class TerbaruSimasCard extends ListActivity {
String nama1,alamat1,ket1,img_id1,telp1,begdate1,enddate1;
private ProgressDialog dialog;
private ArrayList<TerbaruModel>ListTerbaru;
ListView list;
#Override
protected void onCreate(Bundle savedInstanceState) {
//hide title bar
BasicDisplaySettings.toggleTaskBar(TerbaruSimasCard.this, false);
//show status bar
BasicDisplaySettings.toggleStatusBar(TerbaruSimasCard.this, true);
SharedPreferences settings = getSharedPreferences("PREFS_NAME", 0);
settings.edit().clear().commit();
super.onCreate(savedInstanceState);
setContentView(R.layout.terbarusimascard);
ListTerbaru= new ArrayList<TerbaruModel>();
new TerbaruAsyncTask().execute();
}
public class TerbaruAsyncTask extends AsyncTask<Void, Void, String> {
String url = ("http://www.abc.xyz/sc_merchant.htm?s=3&d=25");
public TerbaruAsyncTask() {
this.url=url;
}
protected void onPreExecute (){
super.onPreExecute();
dialog = ProgressDialog.show(TerbaruSimasCard.this,"", "melakukan pengambilan data...");
}
#Override
protected String doInBackground(Void... params) {
String result = "";
try {
result= Connection.get(url);
} catch (Exception e){
result = "";
Log.d("test", e.getMessage());
}
return result;
}
#Override
protected void onPostExecute (String result){
super.onPostExecute(result);
fetchResponse(result.replace("\n","").trim());
dialog.dismiss();
ListView lv = getListView();
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Intent detail= new Intent (TerbaruSimasCard.this, TerbaruDetail.class);
detail.putExtra("nama", nama1);
detail.putExtra("alamat",alamat1);
detail.putExtra("ket", ket1);
detail.putExtra("telp",telp1);
detail.putExtra("begdate", begdate1);
detail.putExtra("enddate",enddate1);
detail.putExtra("img_id", img_id1);
System.out.println(nama1);
startActivity (detail);
}
});
}
}
private void fetchResponse (String result){
if (!result.equals("")){
try {
JSONArray jsonArray = new JSONArray(result);
TerbaruModel LT=null;
for (int i= 0; i < jsonArray.length(); i++) {
JSONObject jsonObject= jsonArray.getJSONObject (i);
LT= new TerbaruModel (jsonObject.optString("kat"),
img_id1=jsonObject.optString("img_id"),
nama1= jsonObject.optString("nama"),
alamat1=jsonObject.optString("alamat"),
ket1=jsonObject.optString("ket"),
jsonObject.optString("tgl"),
jsonObject.optString("accday"),
telp1=jsonObject.optString("telp"),
begdate1=jsonObject.optString("begdate"),
enddate1=jsonObject.optString("enddate")
);
ListTerbaru.add(LT);
list=(ListView)findViewById(android.R.id.list);
setListAdapter (new TerbaruAdapter(this, ListTerbaru));
}
this is for detail:
public class TerbaruDetail extends Activity {
String nama1,alamat1,ket1,img_id1,telp1,begdate1,enddate1;
#Override
public void onCreate (Bundle savedInstanceState){
SharedPreferences settings = getSharedPreferences("PREFS_NAME", 0);
settings.edit().clear().commit();
//hide title bar
BasicDisplaySettings.toggleTaskBar(TerbaruDetail.this, false);
//show status bar
BasicDisplaySettings.toggleStatusBar(TerbaruDetail.this, true);
super.onCreate(savedInstanceState);
setContentView(R.layout.detailviewer);
Intent detail= getIntent();
nama1=detail.getStringExtra("nama");
alamat1= detail.getStringExtra("alamat");
ket1= detail.getStringExtra("ket");
img_id1= detail.getStringExtra("img_id");
telp1= detail.getStringExtra("telp");
begdate1= detail.getStringExtra("begdate");
enddate1= detail.getStringExtra("enddate");
System.out.println(nama1+"nama");
TextView detail_phone=(TextView) findViewById(R.id.detail_phone);
TextView detail_begdate=(TextView) findViewById(R.id.begdate);
TextView detail_enddate=(TextView) findViewById(R.id.endate);
TextView detail_name =(TextView) findViewById(R.id.detail_name);
TextView detail_adress =(TextView) findViewById(R.id.detail_adress);
TextView keterangan =(TextView) findViewById(R.id.keterangan);
ImageView detail_img_id= (ImageView) findViewById(R.id.img_kategori);
detail_name.setText(nama1);
detail_phone.setText(telp1);
detail_begdate.setText(begdate1);
detail_enddate.setText(enddate1);
detail_adress.setText(alamat1);
keterangan.setText(ket1);
}

If You do not mind just delete the app then reload the apk.
From what I know the Shared Preferences value will remain until you uninstall an app.
If the above did not work then try to deleted manually
/data/data/com.package.name/shared_prefs/PREFS_NAME.xml

If you just want to clear out your data (because it is corrupt or whatever), you can do that manually from the home screen. setting -> application manager -> "your app" -> clear data

SharedPreferences.Editor.clear() will not delete the sharedpreferences file, it only clears the contents in this file.
If you really want to delete this file, you should use file operation , sharedprefereces file location is /data/data/com.yourpackage.name/shared_prefs/filename.xml. BTW, you'd better use intent to send data between activities.