Send JSON array from android to Php

I have to store an array of products ids, description, quantity and total price to the database. I defined the json parser class, and userfunctions class. before this I sent only single value of Json for each variables. I have problem to send it as array based on my current codes. Below are the codes the array of products.

public class ScreenSecondFragment extends Fragment {

public ScreenSecondFragment(){}
public double pFinalPrice;
public double[] pTotalPrice;
public String[] sPID;
public String[] sProduct;
public String[] sQuantity;
public String[] sTotalPrice;
public String sFinalPrice;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_secondscreen, container, false);
    TextView showCartContent    = (TextView)rootView.findViewById(R.id.showCart);
    final Button thirdBtn       = (Button) rootView.findViewById(R.id.third);

    //Get Global Controller Class obiect (see application tag in AndroidManifest.xml)
    final Controller aController = (Controller) getActivity().getApplicationContext();

    // Get Cart Size
    final int cartSize = aController.getCart().getCartSize();


    if(cartSize >0)
    {
        for(int i=0;i<cartSize;i++)
        {   
            final int counter = i;
            // Get probuct data from product data arraylist
            String pID = aController.getProducts(i).getProductId();
            sPID[i] = pID;
            String pName = aController.getProducts(i).getProductName();
            sProduct[i] = pName;
            double pPrice   = aController.getProducts(i).getProductPrice();
            int pQuantity   = aController.getProducts(i).getProductQuantity();
            sQuantity[i] = Integer.toString(pQuantity);
            pTotalPrice[i] = pPrice * pQuantity;
            sTotalPrice[i] = Double.toString(pTotalPrice[i]); 

            TableRow row= new TableRow(this.getActivity());
            row.setBackgroundColor(android.graphics.Color.WHITE);

            TextView product = new TextView(this.getActivity());
            product.setText(pName+"    ");
            product.setTextSize(15);
            //Add textView to LinearLayout
            row.addView(product);

            TextView price = new TextView(this.getActivity());
            price.setText(String.format("RM %.2f",pPrice));
            price.setTextSize(15);
            //Add textView to LinearLayout
            row.addView(price);

            TextView quantity = new TextView(this.getActivity());
            quantity.setText(pQuantity+"     ");
            quantity.setTextSize(15);
            //Add textView to LinearLayout
            row.addView(quantity);

            TextView totalprice = new TextView(this.getActivity());
            totalprice.setText(String.format("RM %.2f",pTotalPrice[i]));
            totalprice.setTextSize(15);
            //Add textView to LinearLayout
            row.addView(totalprice);

            //Update final price
            pFinalPrice += pTotalPrice[i];

            final int index = i;
            Log.i("TAG", "index :" + index);
            // Get product instance for index

            final ModelProducts tempProductObiect = aController.getProducts(index);

            final Button btnRemove = new Button(this.getActivity());
            btnRemove.setId(i+1);
            btnRemove.setText("Delete");

            btnRemove.setOnClickListener(new OnClickListener()
            {
                @Override public void onClick(View v)
                {

                    if(aController.getCart().checkProductInCart(tempProductObiect))
                    {
                        // Product not Exist in cart so add product to
                        // Cart product arraylist
                        aController.getCart().removeProducts(tempProductObiect);

                        pFinalPrice -= pTotalPrice[counter];
                        sFinalPrice = Double.toString(pFinalPrice);
                        finalprice.setText(String.format("RM %.2f",pFinalPrice));
                        Toast.makeText(getActivity().getApplicationContext(), "Now Cart size: "+aController.getCart().getCartSize(), 
                                Toast.LENGTH_LONG).show();
                    }
                    // row is your row, the parent of the clicked button
                    View row = (View) v.getParent();
                    // container contains all the rows, you could keep a variable somewhere else to the container which you can refer to here
                    ViewGroup container = ((ViewGroup)row.getParent());
                    // delete the row and invalidate your view so it gets redrawn
                    container.removeView(row);
                    container.invalidate();

                }
            });

            row.addView(btnRemove);

            ll.addView(row,i+1, params);            
        }
    }


    thirdBtn.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            if(cartSize >0)
            {

                FragmentTransaction mFragmentTransaction = getFragmentManager().beginTransaction();
                mFragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE); 
                mFragmentTransaction.replace(R.id.frame_container, new BillingAddressOriFragment(), "Cart");
                mFragmentTransaction.commit();
            }
            else
                Toast.makeText(getActivity().getApplicationContext(), 
                        "Shopping cart is empty.", 
                        Toast.LENGTH_LONG).show();
        }
    }); 
    return rootView;
}

 private class ProcessOrder extends AsyncTask<String, String, JSONObject> {

        private ProgressDialog pDialog;

            /** This should be arrray of product
        String username, pid, products, quantity, totalprice, finalprice;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            DatabaseHandler db = new DatabaseHandler(getActivity().getApplicationContext());

            HashMap<String,String> user = new HashMap<String, String>();
            user = db.getUserDetails();

            username = user.get("username");

            pDialog = new ProgressDialog(ScreenSecondFragment.this.getActivity());
            pDialog.setTitle("Contacting Servers");
            pDialog.setMessage("Getting Data ...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();
        }

        @Override
        protected JSONObject doInBackground(String... args) {

                /** This is where I should send the array of product to userFunction class**/
            UserFunctions userFunction = new UserFunctions();
            JSONObject json = userFunction.orderDetails(username, pid, products, quantity, totalprice, finalprice);

            Log.d("Button", "Order");
            return json;


        }


  }

 public void NetAsync(View view){
     new ProcessOrder().execute();
 }
              }

This is the user function class that should send the value to the php by using json parser. However I dont have idea to convert it to send it as array.

public class UserFunctions {
private JSONParser jsonParser;

//URL of the PHP API
private static String orderURL = "http://www.xxx.com/xxxx_login_api/";

private static String order_tag = "order";

// constructor
public UserFunctions(){
    jsonParser = new JSONParser();
}


/**
 * Function store order details
 **/
public JSONObject orderDetails(String username, String pid, String products, String quantity, String totalprice, String finalprice) {
    // Building Parameters
    List params = new ArrayList();
    params.add(new BasicNameValuePair("tag", billing_tag));
    params.add(new BasicNameValuePair("pid", pid));
    params.add(new BasicNameValuePair("username", username));
    params.add(new BasicNameValuePair("products", products));
    params.add(new BasicNameValuePair("quantity", quantity));
    params.add(new BasicNameValuePair("totalprice", totalprice));
    params.add(new BasicNameValuePair("final", finalprice));
    JSONObject json = jsonParser.getJSONFromUrl(orderURL,params);
    return json;
} 


   } 
}

This is the JSON parser class.

public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url, List params) {
    // Making HTTP request
    try {
        // defaultHttpClient
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpPost httpPost = new HttpPost(url);
        httpPost.setEntity(new UrlEncodedFormEntity(params));
        HttpResponse httpResponse = httpClient.execute(httpPost);
        HttpEntity httpEntity = httpResponse.getEntity();
        is = httpEntity.getContent();
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    try {
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                is, "iso-8859-1"), 8);
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
        is.close();
        json = sb.toString();
        Log.e("JSON", json);
    } catch (Exception e) {
        Log.e("Buffer Error", "Error converting result " + e.toString());
    }
    // try parse the string to a JSON object
    try {
        jObj = new JSONObject(json);
    } catch (JSONException e) {
        Log.e("JSON Parser", "Error parsing data " + e.toString());
    }
    // return JSON String
    return jObj;
}
}

I need to store the array data to the mysql table as below
Table : view_order column : OrderID, ProductID(foreign key), quantity, total_price, final_final

I wish I know how to edit the json and function plus write the php code to decode the JSON and store it to database. Thanks