如何将发布值传递到服务器并将结果存储在列表视图Android中

Question

this is my listview where data is coming from the remote server in the JSON format so everything is working fine but now I have to pass a certain value to the server and then make a filter based on that value and then load only the desired result into the listview

public class Reciepe extends AppCompatActivity {

String Barname;
TextView food,price;
private ListView reciepeListView;
private ProgressDialog loading;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_reciepe);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    toolbar.setBackgroundColor(Color.parseColor("#FFBC03"));
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    new JSONTask().execute("http://thehostels.in/Foody/reciepe_json.php");
    DisplayImageOptions options = new DisplayImageOptions.Builder()

            .cacheInMemory(true)
            .cacheOnDisk(true)

            .build();
    ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(Reciepe.this)
            .defaultDisplayImageOptions(options)
            .build();
    com.nostra13.universalimageloader.core.ImageLoader.getInstance().init(config);
    reciepeListView = (ListView)findViewById(R.id.list_recipe);



    Intent intent=getIntent();
    if(intent!=null){

        Barname=intent.getStringExtra("Type");
        Log.e("Type",Barname);
    }

    if (Barname != null) {

        switch (Barname) {
            case "Punjabi":

                getSupportActionBar().setTitle("Punjabi");
                break;
            case "Chinese":

                getSupportActionBar().setTitle("Chinese");
                break;
            case "South Indian":

                getSupportActionBar().setTitle("South Indian");
                break;
            case "Gujarati":

                getSupportActionBar().setTitle("Gujarati");
                break;
            case "Chicken":

                getSupportActionBar().setTitle("Chicken");
                break;
        }
    }
    }



public class JSONTask extends AsyncTask<String, String, List<Listview_reciepe_conveyer>> {

    ProgressDialog loading;


    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        loading = ProgressDialog.show(Reciepe.this, "loading,please wait...", null, true, true);
    }

    @Override
    protected List<Listview_reciepe_conveyer> doInBackground(String... params) {
        HttpURLConnection connection = null;
        BufferedReader reader = null;

        try {

            URL url = new URL(params[0]);
            connection = (HttpURLConnection) url.openConnection();
            connection.connect();

            InputStream stream = connection.getInputStream();
            reader = new BufferedReader(new InputStreamReader(stream));
            StringBuffer buffer = new StringBuffer();
            String line = "";
            while ((line = reader.readLine()) != null) {
                buffer.append(line);
            }


            String finalJson = buffer.toString();
            JSONObject parentObject = new JSONObject(finalJson);
            JSONArray parentArray = parentObject.getJSONArray("list");
            List<Listview_reciepe_conveyer> fixture_conveyerList = new ArrayList<Listview_reciepe_conveyer>();

            for (int i = 0; i < parentArray.length(); i++) {
                JSONObject finalObject = parentArray.getJSONObject(i);
                Listview_reciepe_conveyer fixtureList = new Listview_reciepe_conveyer();
                fixtureList.setImage(finalObject.getString("image"));
                fixtureList.setFood(finalObject.getString("food"));
                fixtureList.setPrice(finalObject.getString("price"));

                fixture_conveyerList.add(fixtureList);
            }

            return fixture_conveyerList;




        }catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (JSONException e) {
            e.printStackTrace();
        } finally {
            if (connection != null) {
                connection.disconnect();
            }
            try {
                if (reader != null) {
                    reader.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    @Override
    protected void onPostExecute(List<Listview_reciepe_conveyer> result) {
        super.onPostExecute(result);

        if (result !=null) {
            loading.dismiss();
            ListAdapter adapter = new ListAdapter(Reciepe.this, R.layout.custom_recipe_list, result);
            reciepeListView.setAdapter(adapter);

        }
        else
        {

            Toast.makeText(Reciepe.this, "No Internet Connection!", Toast.LENGTH_LONG).show();
            loading.dismiss();
        }

    }
}



public class ListAdapter extends ArrayAdapter {

    private List<Listview_reciepe_conveyer> reciepe_conveyerList;
    private int resource;
    private LayoutInflater inflater;

    public ListAdapter(Context context, int resource, List<Listview_reciepe_conveyer> objects) {
        super(context, resource, objects);
        reciepe_conveyerList = objects;
        this.resource = resource;
        inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        if (convertView == null) {

            convertView = inflater.inflate(resource, null);
        }

        ImageView food_photo;
        final TextView food,price;


        food_photo = (ImageView)convertView.findViewById(R.id.food_photo);
        food = (TextView)convertView.findViewById(R.id.food_name);
        price = (TextView)convertView.findViewById(R.id.food_price);

        ImageLoader.getInstance().displayImage(reciepe_conveyerList.get(position).getImage(), food_photo);

        food.setText(reciepe_conveyerList.get(position).getFood());

        String newprice= ("Rs."+reciepe_conveyerList.get(position).getPrice());
        price.setText(newprice);


        reciepeListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                                                   @Override
                                                   public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

                                                       Intent i=new Intent(Reciepe.this,Description.class);
                                                       i.putExtra("Dish",reciepe_conveyerList.get(position).getFood());
                                                       i.putExtra("Price",reciepe_conveyerList.get(position).getPrice());
                                                       startActivity(i);
                                                   }
                                               }

        );



        return convertView;
    }
}

  }

this is what my code looks like where i am loading a list from an api,

so i am using AsyncTask to load the listview but i do not know how to make the post request , i have updated the api it os taking the post values but what changes do i need to make on android level.., i have to pass the 'barname' as the post parameter...

Answer 1

On:

protected List<Listview_reciepe_conveyer> doInBackground(String... params) {

Try:

HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
conn.setReadTimeout(10000);
conn.setConnectTimeout(15000);
conn.setRequestMethod("POST");
conn.setDoInput(true);
conn.setDoOutput(true);

List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>();

params.add(new BasicNameValuePair("firstParam", "paremeterValue")); 
//your param nr.1. 
//This is the value that you want to send. 
//It is represented like 'name=value', or in your case 'firstParam=parameterValue'. 
//You need to edit this field in respect to what you are doing. 

params.add(new BasicNameValuePair("secondParam", "your2parameter")); 
//your param nr.2 
//This is the value that you want to send. 
//It is represented like 'name=value', or in your case 'secondParam=your2parameter'. 
//You need to edit this field in respect to what you are doing. 


params.add(new BasicNameValuePair("thirdParam", "anotherParameter")); 
//your param nr.3
//This is the value that you want to send. 
//It is represented like 'name=value', or in your case 'thirdParam=anotherParameter'. 
//You need to edit this field in respect to what you are doing. 


// Write(add) parameters to your request

OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(
        new OutputStreamWriter(os, "UTF-8"));
writer.write(getQuery(params));
writer.flush();
writer.close();
os.close();

conn.connect();

Before your..:

InputStream stream = connection.getInputStream(); reader = new BufferedReader(new InputStreamReader(stream)); ...

---

EDITED

private String getQuery(List<BasicNameValuePair> params) throws UnsupportedEncodingException
{
    StringBuilder result = new StringBuilder();
    boolean first = true;

    for (String pair : params)
    {
        if (first)
            first = false;
        else
            result.append("&");

        result.append(URLEncoder.encode(pair.getName(), "UTF-8"));
        result.append("=");
        result.append(URLEncoder.encode(pair.getValue(), "UTF-8"));
    }

    return result.toString();
}

This function turn's the List params, in a String with the format, 'name=value' which is needed to send via request.

For more info see Query String .

Please do NOT copy and paste the solution, you also need to understand what you are doing and replace variables/methods accordingly, for this code to work.

Best