JSON Parsing Issue with Spinners

Question

All my spinners are connected with each other, they are not independent, I would like to show options in spinner2 and spinner3 based on the selection in spinner1 (I mean based on category chosen by user in spinner1)

In onCreate I am populating data into Spinners, but in spinner2 and spinner3 I am getting data that belongs to CategoryB whereas they must populate with CategoryA data only.

So where is my mistake? Here is my JSON Parsing code:

               categoryArrayList = new ArrayList<Category>();
               cArrayList = new ArrayList<String>();

                ...................................

                // Array Level 1 --- START
            JSONArray jarray = jsono.getJSONArray("categories");

            for (int i = 0; i < jarray.length(); i++) {
                JSONObject object = jarray.getJSONObject(i);

                Category language = new Category();                     
                language.setName(object.getString("category_name"));
                Log.d("category_name::-", object.getString("category_name"));

                language.setTypeArrayList(typeArrayList);
                categoryArrayList.add(language);
                cArrayList.add(categoryArrayList.get(i).getName());

                // Array Level 1 --- END

                // Array Level 2 --- START

                JSONArray jsarray = object.getJSONArray("types");
                typeArrayList = new ArrayList<Type>();
                tArrayList = new ArrayList<String>();
                for (int j = 0; j < jsarray.length(); j++) {
                    JSONObject jjobject = jsarray.getJSONObject(j);

                    Type genre = new Type();

                    genre.setName(jjobject.getString("type_name"));
                    Log.d("type_name::-", jjobject.getString("type_name"));     

                    genre.setServiceArrayList(serviceArrayList);
                    typeArrayList.add(genre);
                    tArrayList.add(typeArrayList.get(j).getName());     

                    // Array Level 2 --- END

                    // Array Level 3 --- START

                    JSONArray jsonarray = jjobject.getJSONArray("services");
                    serviceArrayList = new ArrayList<Service>();
                    sArrayList = new ArrayList<String>();
                    for (int k = 0; k < jsonarray.length(); k++) {
                        JSONObject jjjobject = jsonarray.getJSONObject(k);

                        Service movie = new Service();

                        movie.setName(jjjobject.getString("service_name"));
                        Log.d("service_name::-", jjjobject.getString("service_name"));

                        serviceArrayList.add(movie);    
                        sArrayList.add(serviceArrayList.get(k).getName());

                        // Array Level 3 --- END
                    }

                }       

            }

            return true;
        }

And here is how i am populating Spinners:

            spinner1.setAdapter(new ArrayAdapter<String>(CategoryActivity.this,
                     android.R.layout.simple_spinner_dropdown_item,
                     cArrayList));

            spinner2.setAdapter(new ArrayAdapter<String>(CategoryActivity.this,
                    android.R.layout.simple_spinner_dropdown_item,
                    tArrayList));

            spinner3.setAdapter(new ArrayAdapter<String>(CategoryActivity.this,
                    android.R.layout.simple_spinner_dropdown_item,
                    sArrayList));

I think you should correct you expected out in `spinner3` because it do not refer to `Category A` array — Iamat8, Sep 11 '15 at 05:13
@Mohit but my spinners are connected with each other if user select Category A in spinner1 then only show data that belongs to CategoryA in spinner2 and spinner3, in a same way for CategoryB... — Oreo, Sep 11 '15 at 05:15
that's what I am reffering ....please trace you expected output to your json..I mean there is no `CatA TypeB ServiceA` in `"category_name":"Category A",` — Iamat8, Sep 11 '15 at 05:17
Can you please post what exact value should be in `spinner2,spinner3` when your select `"Category A"` — Iamat8, Sep 11 '15 at 05:49
@ρяσѕρєяK no bhaiya still facing issue, tried everything i know, now i need your help — Oreo, Sep 12 '15 at 05:56
@ρяσѕρєяK bhaiya getting: Type mismatch: cannot convert from String to ArrayList : at this point: ArrayList arrtype_name=categoryArrayList.get(0).getName(); — Oreo, Sep 12 '15 at 07:08
@ρяσѕρєяK bhaiya getting NPE here: ArrayList arrtype_name=categoryArrayList.get(0).getTypeArrayList(); ... check this: http://paste.ofcode.org/kqe4pnLiQ88hQTZRU6zdYF — Oreo, Sep 12 '15 at 07:20
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/89444/discussion-between--k-and-oreo). — ρяσѕρєя K, Sep 12 '15 at 07:21
@ρяσѕρєяK bhaiya aapke bhai ko apki help chahiye: http://stackoverflow.com/questions/32946441/recyclerview-endless-infinite-scrolling-issue — Oreo, Oct 06 '15 at 07:55

arun · Answer 1 · 2015-09-14T04:52:12.447

Oreo. Here is the full code.

Category class

public class Category {

    String name;
    ArrayList<ArrayList<Type>> type;
    Category()
    {
        name = "";
        type = new ArrayList<ArrayList<Type>>(); 
    }

    void setName(String s)
    {
        name =s;
    }

    public String getName()
    {
        return name;
    }

    void setTypeArrayList(ArrayList<Type> serviceArrayList)
    {
        type.add(serviceArrayList);
    }

    ArrayList<Type> getTypeArrayList(int i)
    {
        return type.get(i);
    }
}

Type class

import java.util.ArrayList;

public class Type {
    String type;
    ArrayList<ArrayList<Service>> service;

    public Type() {
        // TODO Auto-generated constructor stub
        type = "";
        service = new ArrayList<ArrayList<Service>>();
    }
    void setName(String s)
    {
        type =s;
    }

    public String getName()
    {
        return type;
    }

    void setServiceArrayList(ArrayList<Service> serviceArrayList)
    {
        service.add(serviceArrayList);
    }

    ArrayList<Service> getServiceArrayList(int i)
    {
        return service.get(i);
    }
}

Service class

public class Service {

    String service;

    public Service() {
        // TODO Auto-generated constructor stub
        service ="";
    }

    void setName(String s)
    {
        service =s;
    }

    public String getName()
    {
        return service;
    }
}

initialize global

 int catpos =0;
 ArrayList<Category> categoryArrayList = new ArrayList<Category>();
 ArrayList<String> cArrayList = new ArrayList<String>();
 ArrayList<Type> typeArrayList;
 ArrayList<Service> serviceArrayList;

doInbackground

    //your http request and response process


    JSONObject jsono;
    try {
        jsono = new JSONObject(data);

        JSONArray jarray = jsono.getJSONArray("categories");

        for (int i = 0; i < jarray.length(); i++) {
            JSONObject object = jarray.getJSONObject(i);

            Category language = new Category();
            language.setName(object.getString("category_name"));
            Log.d("category_name::-", object.getString("category_name"));

            JSONArray jsarray = object.getJSONArray("types");
            typeArrayList = new ArrayList<Type>();
            tArrayList = new ArrayList<String>();
            for (int j = 0; j < jsarray.length(); j++) {
                JSONObject jjobject = jsarray.getJSONObject(j);

                Type genre = new Type();

                genre.setName(jjobject.getString("type_name"));
                Log.d("type_name::-", jjobject.getString("type_name"));

                JSONArray jsonarray = jjobject.getJSONArray("services");
                serviceArrayList = new ArrayList<Service>();
                sArrayList = new ArrayList<String>();
                for (int k = 0; k < jsonarray.length(); k++) {
                    JSONObject jjjobject = jsonarray.getJSONObject(k);

                    Service movie = new Service();

                    movie.setName(jjjobject.getString("service_name"));
                    Log.d("service_name::-",
                            jjjobject.getString("service_name"));

                    serviceArrayList.add(movie);
                    sArrayList.add(serviceArrayList.get(k).getName());
                }
                genre.setServiceArrayList(serviceArrayList);
                typeArrayList.add(genre);
                tArrayList.add(typeArrayList.get(j).getName());
            }

            language.setTypeArrayList(typeArrayList);
            categoryArrayList.add(language);
            cArrayList.add(categoryArrayList.get(i).getName());

        }
    } catch (JSONException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

onPostExecute Method

    tArrayList = new ArrayList<String>();
    sArrayList = new ArrayList<String>();

    Category c = categoryArrayList.get(0);      
    typeArrayList = c.getTypeArrayList(0);
    for(int i=0;i<typeArrayList.size();i++)
        tArrayList.add(typeArrayList.get(i).getName());
    Type t = typeArrayList.get(0);
    serviceArrayList = t.getServiceArrayList(0);
    for(int i=0;i<serviceArrayList.size();i++)
        sArrayList.add(serviceArrayList.get(i).getName());

    spinner1.setAdapter(new ArrayAdapter<String>(CategoryActivity.this,
            android.R.layout.simple_spinner_dropdown_item, cArrayList));

    spinner2.setAdapter(new ArrayAdapter<String>(CategoryActivity.this,
            android.R.layout.simple_spinner_dropdown_item, tArrayList));


    spinner3.setAdapter(new ArrayAdapter<String>(CategoryActivity.this,
            android.R.layout.simple_spinner_dropdown_item, sArrayList));

    spinner1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        public void onItemSelected(AdapterView<?> parent, View view,
                int pos, long id) {

            catpos = pos;
            tArrayList = new ArrayList<String>();
            sArrayList = new ArrayList<String>();
            Category c = categoryArrayList.get(pos);        
            typeArrayList = c.getTypeArrayList(0);
            for(int i=0;i<typeArrayList.size();i++)
                tArrayList.add(typeArrayList.get(i).getName());
            Type t = typeArrayList.get(0);
            serviceArrayList = t.getServiceArrayList(0);
            for(int i=0;i<serviceArrayList.size();i++)
                sArrayList.add(serviceArrayList.get(i).getName());

            spinner2.setAdapter(new ArrayAdapter<String>(CategoryActivity.this,
                    android.R.layout.simple_spinner_dropdown_item, tArrayList));


            spinner3.setAdapter(new ArrayAdapter<String>(CategoryActivity.this,
                    android.R.layout.simple_spinner_dropdown_item, sArrayList));


        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub

        }
    });

    spinner2.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        public void onItemSelected(AdapterView<?> parent, View view,
                int pos, long id) {

            sArrayList = new ArrayList<String>();
            Category c = categoryArrayList.get(catpos);     
            typeArrayList = c.getTypeArrayList(0);              
            Type t = typeArrayList.get(pos);
            serviceArrayList = t.getServiceArrayList(0);
            for(int i=0;i<serviceArrayList.size();i++)
                sArrayList.add(serviceArrayList.get(i).getName());

            spinner3.setAdapter(new ArrayAdapter<String>(CategoryActivity.this,
                    android.R.layout.simple_spinner_dropdown_item, sArrayList));                
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub

        }
    });

sorry but i need solution in my existing code, because i know i am doing a very little mistake.. would you point out me my mistake, ok just let me know how can i use this line in my code as per my existing code: tArrayList = hasMap.get(categories.get(0)); — Oreo, Sep 11 '15 at 06:29
can you just tell me, what i have should write in my existing code to get this: tArrayList = hasMap.get(categories.get(0)); because this is the only thing i am missing in my code, this will show spinner2 with categoryA items only in onCreate — Oreo, Sep 11 '15 at 06:45
if you did your tArrayList and sArrayList contains the last loop values that's category B -->types on your tArrayList and types 2nd service on your sArrayList. — arun, Sep 11 '15 at 06:45
i know that's why i am asking you for the solution, modify this line as per my existing code: tArrayList = hasMap.get(categories.get(0)); — Oreo, Sep 11 '15 at 06:48
that is initialize the spinner on onCreate method. categories.get(0) returns first "Category A" type. — arun, Sep 11 '15 at 06:51
yes i know that's why i am saying modify this line as per my existing code — Oreo, Sep 11 '15 at 06:54
here is my attempt with your method : http://stackoverflow.com/questions/32535612/arraylist-null-pointer-exception-in-onpostexecute — Oreo, Sep 12 '15 at 06:43

score 2 · Answer 2 · answered Sep 11 '15 at 05:36

This should do what you want, however, I am not sure why you are reading a json, but you seems to know the content already. i.e. you want something so specific in spinner 3

           categoryArrayList = new ArrayList<Category>();
           cArrayList = new ArrayList<String>();

            ...................................

            JSONArray jarray = jsono.getJSONArray("categories");

            for (int i = 0; i < jarray.length(); i++) {
                JSONObject object = jarray.getJSONObject(i);

                Category language = new Category();                     
                language.setName(object.getString("category_name"));
                Log.d("category_name::-", object.getString("category_name"));

                language.setTypeArrayList(typeArrayList);
                categoryArrayList.add(language);
                cArrayList.add(categoryArrayList.get(i).getName());

            }

            JSONArray jsarray = jarray.getJSONObject(0).getJSONArray("types");
            typeArrayList = new ArrayList<Type>();
            tArrayList = new ArrayList<String>();
            for (int j = 0; j < jsarray.length(); j++) {
                JSONObject jjobject = jsarray.getJSONObject(j);

                Type genre = new Type();

                genre.setName(jjobject.getString("type_name"));
                Log.d("type_name::-", jjobject.getString("type_name"));                     

                genre.setServiceArrayList(serviceArrayList);
                typeArrayList.add(genre);
                tArrayList.add(typeArrayList.get(j).getName());         
            }       

            JSONArray jsonarray = jsarray.getJSONObject(1).getJSONArray("services");
            serviceArrayList = new ArrayList<Service>();
            sArrayList = new ArrayList<String>();
            for (int k = 0; k < jsonarray.length(); k++) {
                JSONObject jjjobject = jsonarray.getJSONObject(k);

                Service movie = new Service();

                movie.setName(jjjobject.getString("service_name"));
                Log.d("service_name::-", jjjobject.getString("service_name"));

                serviceArrayList.add(movie);    
                sArrayList.add(serviceArrayList.get(k).getName());
            }
            return true;

no not at all my all the spinners are connected with each other (if i have to make them) they are not independent, i would like to show options in spinner2 and spinner3 based on the selection in spinner1 — Oreo, Sep 11 '15 at 06:19

score 2 · Answer 3 · answered Sep 16 '15 at 07:26

My strategy would be:

1) First, populate your spinner 1 and populate your spinner 2, 3 according to selected item (which is first item) of spinner 1.

2) Put spinner1.setOnItemSelectedListener() and send an event when item is changed on spinner 1 inside this method. To send event, use Otto.

3) Register Otto on your Activity, Fragment and @Subscribe to that event. So when you select item in spinner 1 you will get notified immediately inside @Subscribe and you have to change your spinner 2,3 with spinner1.setAdapter() and spinner2.setAdapter() in there.

George · Answer 4 · 2015-09-21T11:44:14.033

You tArrayList is being populated wrongly. You're populating your Spinner with this code:

        spinner2.setAdapter(new ArrayAdapter<String>(CategoryActivity.this,
                android.R.layout.simple_spinner_dropdown_item,
                tArrayList));

But the variable tArrayList is only getting the last value that it reads. You're using a for loop, but on every loop you restart the tArrayList variable, so at the end it will have only the last value.

[...]
for (int i = 0; i < jarray.length(); i++) {
        [...]
        tArrayList = new ArrayList<String>();

One of the solutions could be something like that:

Create a List of Lists
At each loop, you create a new tArrayList variable and initialize it.
At the end of the second for loop (where you populate it) you add the created list to the global list of lists.
When you select and option from the spinner1, you get that position from the List of list and use it to populate your spinner2.

List<List<String>> tArrayListOfLists = new ArrayList<ArrayList<>>();
for(...){ // First for loop
    List<String> tArrayList = new ArrayList<>();
    for(...) { // Second for loop
         tArrayList.add("your strings");
    }
    tArrayListOfLists.add(tArrayList);
}

Then you'll have a list of lists with the items you need. To list for the user selection on the spinner and fill it:

spinner1.setOnItemSelectedListener(new OnItemSelectedListener() 
{
    @Override
    public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) 
    {
        // Get the selected position
        List<String> selectedList = tArrayListOfLists.get(position);

        spinner2.setAdapter(new ArrayAdapter<String>(CategoryActivity.this,
        android.R.layout.simple_spinner_dropdown_item, selectedList));
    }

    @Override
    public void onNothingSelected(AdapterView<?> parentView) {
        // Clear the list 2
    }
});

score 2 · Answer 5 · edited Nov 16 '15 at 19:23

Taken from this site:

This example shows how to populate second spinner based on selection of first spinner.

XML: Layout File Entry

res/layout/activity_spinner_ex4.xml

<?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="fill_parent"
    android:orientation="vertical" >

    <!-- Label -->

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:padding="8dip"
        android:text="@string/lblAcc" />

    <!-- Spinner Dropdown -->

    <Spinner
        android:id="@+id/spinner1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="8dip"
        android:layout_marginRight="8dip"
        android:layout_marginTop="10dip"
        android:entries="@array/acc_type" />

    <!-- Select Label -->

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:padding="8dip"
        android:text="@string/lblSubAcc" />

    <!-- Spinner Dropdown -->
    <Spinner
        android:id="@+id/spinner2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dip"
        android:layout_marginLeft="8dip"
        android:layout_marginRight="8dip"
    />
</LinearLayout>

XML: Strings File Entries

res/values/strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">Spinner Example</string>
    <string name="action_settings">Settings</string>
    <string name="lblAcc">Select Account Type</string>
    <string name="lblSubAcc">Select Account Head</string>

    <string-array name="acc_type">
        <item>Income</item>
        <item>Expense</item>
    </string-array>

</resources>

Main Activity

SpinnerEx4Activity.java

package com.bar.example.androidspinnerexample;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.Toast;

public class SpinnerEx4Activity extends Activity implements
OnItemSelectedListener{
Spinner s1,s2;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_spinner_ex4);
        s1 = (Spinner)findViewById(R.id.spinner1);
        s2 = (Spinner)findViewById(R.id.spinner2);
        s1.setOnItemSelectedListener(this);
    }
    @Override
    public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
            long arg3) {
        // TODO Auto-generated method stub
        String sp1= String.valueOf(s1.getSelectedItem());
        Toast.makeText(this, sp1, Toast.LENGTH_SHORT).show();
        if(sp1.contentEquals("Income")) {
            List<String> list = new ArrayList<String>();
            list.add("Salary");
            list.add("Sales");
            list.add("Others");
            ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, list);
            dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            dataAdapter.notifyDataSetChanged();
            s2.setAdapter(dataAdapter);
        }
        if(sp1.contentEquals("Expense")) {
            List<String> list = new ArrayList<String>();
            list.add("Conveyance");
            list.add("Breakfast");
            list.add("Purchase");
            ArrayAdapter<String> dataAdapter2 = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, list);
            dataAdapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            dataAdapter2.notifyDataSetChanged();
            s2.setAdapter(dataAdapter2);
        }

    }
    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // TODO Auto-generated method stub

    }
}

JSON Parsing Issue with Spinners

5 Answers5