uunable to pass current activity from asynctask

uunable to pass current activity from asynctask - android

I am trying to pass current activity object to custom listview adapter but am getting nullpointer exception as it is being passed from async class. Here's my code:
public class MainActivity extends Activity {
ListView list;
LazyAdapter adapter;
private ProgressDialog pDialog;
// URL to get contacts JSON
private static String url = "http://api.androidhive.info/contacts/";
// JSON Node names
static final String Events_date = "ev_date";
static final String TAG_CONTACTS = "contacts";
static final String TAG_ID = "id";
static final String TAG_NAME = "name";
static final String TAG_EMAIL = "email";
static final String TAG_ADDRESS = "address";
static final String TAG_GENDER = "gender";
private static final String TAG_PHONE = "phone";
private static final String TAG_PHONE_MOBILE = "mobile";
private static final String TAG_PHONE_HOME = "home";
private static final String TAG_PHONE_OFFICE = "office";
// contacts JSONArray
JSONArray contacts = null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
contactList = new ArrayList<HashMap<String, String>>();
// Calling async task to get json
new GetContacts().execute();
}
/**
* Async task class to get json by making HTTP call
* */
private class GetContacts extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
#Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
contacts = jsonObj.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_GENDER);
// Phone node is JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
String home = phone.getString(TAG_PHONE_HOME);
String office = phone.getString(TAG_PHONE_OFFICE);
// tmp hashmap for single contact
HashMap<String, String> contact = new HashMap<String, String>();
// adding each child node to HashMap key => value
contact.put(TAG_ID, id);
contact.put(TAG_NAME, name);
contact.put(TAG_EMAIL, email);
contact.put(TAG_PHONE_MOBILE, mobile);
// adding contact to contact list
contactList.add(contact);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
list=(ListView)findViewById(R.id.list);
// Getting adapter by passing xml data ArrayList
adapter=new LazyAdapter(this, contactList);
list.setAdapter(adapter);
}
}
}
and here is adapterclass main code snippets
public class LazyAdapter extends BaseAdapter {
private Activity activity;
private ArrayList<HashMap<String, String>> data;
private static LayoutInflater inflater=null;
// public ImageLoader imageLoader;
public LazyAdapter(Activity a, ArrayList<HashMap<String, String>> d) {
activity = a;
data=d;
inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
// imageLoader=new ImageLoader(activity.getApplicationContext());
}
public int getCount() {
return data.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
View vi=convertView;
if(convertView==null)
vi = inflater.inflate(R.layout.list_row, null);
TextView title = (TextView)vi.findViewById(R.id.title); // title
TextView artist = (TextView)vi.findViewById(R.id.artist); // artist name
TextView duration = (TextView)vi.findViewById(R.id.duration); // duration
HashMap<String, String> song = new HashMap<String, String>();
song = data.get(position);
// Setting all values in listview
title.setText(song.get(CustomizedListView.KEY_TITLE));
artist.setText(song.get(CustomizedListView.KEY_ARTIST));
duration.setText(song.get(CustomizedListView.KEY_DURATION));
// imageLoader.DisplayImage(song.get(CustomizedListView.KEY_THUMB_URL), thumb_image);
return vi;
}
}
I understand that I am supposed to pass instance of MainActivity. So,can any one tell me how to do it, as if I am calling a function from postexecute then also getting nullpointer as data is not being inserted in hashmap.Kindly help!!!
Log cat:
01-25 23:08:29.779: D/Response:(607): "name": "Clint Eastwood",
01-25 23:08:29.779: D/Response:(607): "address": "xx-xx-xxxx,x - street, x - coun
01-25 23:08:30.029: D/AndroidRuntime(607): Shutting down VM
01-25 23:08:30.029: W/dalvikvm(607): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
01-25 23:08:30.052: E/AndroidRuntime(607): FATAL EXCEPTION: main
01-25 23:08:30.052: E/AndroidRuntime(607): at info.androidhive.jsonparsing.MainActivity$GetContacts.onPostExecute(MainActivity.java:155)
01-25 23:08:30.052: E/AndroidRuntime(607): at info.androidhive.jsonparsing.MainActivity$GetContacts.onPostExecute(MainActivity.java:1)

Use MainActivity.this to refer to the parent class this in a nested class such as your async task.
However, this requires that you keep your asynctask nested class non-static which isn't a good idea. Non-static nested class hold references to their parent (activity in this case) and since activity and asynctask lifecycles are different, the asynctask can hold onto the wrong activity for too long.

use adapter=new LazyAdapter(MainActivity.this, contactList);
only this will pass the asynctask class context.

You could create a new constructor for the AsyncTask accepting an Activity as input parameter
public GetContacts(Activity mActivity){
this.mActivity = mActivity;}
In the doInBackground method you could then use mActivity but be aware that until you have a reference to the Activity, this one cannot die.
When creating the AsyncTask from the MainActivity, you could just pass this as input parameter and it should work.

Related

Unable to start activity ComponentInfo :java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'

I am new to using json . fetching data from mysql in json format display on listview android . Caused by: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
public class MainActivity extends ListActivity {
private ProgressDialog pDialog;
// URL to get contacts JSON
private static String url= "http://127.0.0.1/bloodRequest/data.php";
// JSON Node names
private static final String TAG_CONTACTS = "requests ";
private static final String TAG_NAME = "User_name";
private static final String TAG_BLOCKNO = "user_block_no";
private static final String TAG_ADDRESS = "user_stree_address";
private static final String TAG_CITY = "user_city_village";
private static final String TAG_TALUKA = "user_taluka";
private static final String TAG_DISTRICT = "user_district";
private static final String TAG_BLOOD_TYPE = "blood_type";
private static final String TAG_CREATE_DATE = "createdate";
private static final String TAG_PHONE = "user_mobile";
// contacts JSONArray
JSONArray requests= null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView list = getListView();
new GetContacts().execute();
}
/**
* Async task class to get json by making HTTP call
* */
private class GetContacts extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
#Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.POST);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
requests = jsonObj.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for (int i = 0; i < requests.length(); i++) {
JSONObject c = requests.getJSONObject(i);
String name = c.getString(TAG_NAME);
String blockno = c.getString(TAG_BLOCKNO);
String address = c.getString(TAG_ADDRESS);
String city = c.getString(TAG_CITY);
String district=c.getString(TAG_DISTRICT);
String taluk=c.getString(TAG_TALUKA);
String blodtype=c.getString(TAG_BLOOD_TYPE);
String phone=c.getString(TAG_PHONE);
String createdate=c.getString(TAG_CREATE_DATE);
// tmp hashmap for single contact
HashMap<String, String> requests1 = new HashMap<String, String>();
// adding each child node to HashMap key => value
requests1 .put(TAG_NAME, name);
requests1 .put(TAG_BLOCKNO, blockno);
requests1 .put(TAG_ADDRESS, address);
requests1 .put(TAG_CITY, city);
requests1 .put(TAG_TALUKA, taluk);
requests1 .put(TAG_DISTRICT, district);
requests1 .put(TAG_BLOOD_TYPE, blodtype);
requests1 .put(TAG_PHONE, phone);
requests1 .put(TAG_CREATE_DATE, createdate);
// adding contact to contact list
contactList.add( requests1 );
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
MainActivity.this, contactList,
R.layout.item_list,
new String[] { TAG_NAME, TAG_BLOCKNO,TAG_ADDRESS,TAG_CITY,TAG_TALUKA,TAG_DISTRICT,TAG_BLOOD_TYPE,TAG_PHONE,TAG_CREATE_DATE},
new int[] { R.id.name, R.id.blono, R.id.street,R.id.city,R.id.taluk,R.id.distr,R.id.btype,R.id.phno,R.id.crdate });
setListAdapter(adapter);
}
}
}

Add to your activity_main ListView with android:id="#android:id/list"
If you use ListActivity in your activity layout you should add:
<ListView
android:id="#android:id/list"
android:layout_width="match_parent"
android:layout_height="match_parent"/>

When you extends ListActivity you should use
ListView list = getListView(); // OR you can do
ListView list = (ListView)findViewById(android.R.id.list); //consider the android prefix
And Set Listview Id android:id="#android:id/list"
<ListView
android:id="#android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
ListView whose id attribute is 'android.R.id.list' Error when I have the ListView id set correctly
Your content must have a ListView whose id attribute is 'android.R.id.list'

how to prevent to show the duplicate and repetatvie value in listview when we update it by swipe down?

i used a list view in my app.i used scroll bar for update the details. i got complete updated list again.which added all the data in ny list. i wants to avoid it so plz suggest me how i retrict the duplicate values in list after updation.... my code snippet is here.....
public class MainActivity extends ListActivity implements SwipeRefreshLayout.OnRefreshListener {
private ProgressDialog pDialog;
ListView mListView;
SwipeRefreshLayout swipeLayout;
Adapter mAdapter;
// URL to get contacts JSON
private static String url = "http://api.androidhive.info/contacts/";
// JSON Node names
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_ADDRESS = "address";
private static final String TAG_GENDER = "gender";
private static final String TAG_PHONE = "phone";
private static final String TAG_PHONE_MOBILE = "mobile";
private static final String TAG_PHONE_HOME = "home";
private static final String TAG_PHONE_OFFICE = "office";
// contacts JSONArray
JSONArray contacts = null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// SwipeRefreshLayout mSwipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.activity_main_swipe_refresh_layout);
swipeLayout = (SwipeRefreshLayout) findViewById(R.id.swipe_container);
swipeLayout.setOnRefreshListener(this);
swipeLayout.setColorScheme(android.R.color.holo_blue_bright,
android.R.color.holo_green_light,
android.R.color.holo_orange_light,
android.R.color.holo_red_light);
contactList = new ArrayList<HashMap<String, String>>();
ListView lv = getListView();
// Listview on item click listener
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name))
.getText().toString();
String cost = ((TextView) view.findViewById(R.id.email))
.getText().toString();
String description = ((TextView) view.findViewById(R.id.mobile))
.getText().toString();
// Starting single contact activity
Intent in = new Intent(getApplicationContext(),
ak.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_EMAIL, cost);
in.putExtra(TAG_PHONE_MOBILE, description);
startActivity(in);
}
});
// Calling async task to get json
new GetContacts().execute();
}
/**
* Async task class to get json by making HTTP call
*/
private class GetContacts extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
// pDialog = new ProgressDialog(MainActivity.this);
// pDialog.setMessage("Please wait...");
// pDialog.setCancelable(false);
//Dialog.show();
}
#Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
contacts = jsonObj.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_GENDER);
// Phone node is JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
String home = phone.getString(TAG_PHONE_HOME);
String office = phone.getString(TAG_PHONE_OFFICE);
// tmp hashmap for single contact
HashMap<String, String> contact = new HashMap<String, String>();
// adding each child node to HashMap key => value
contact.put(TAG_ID, id);
contact.put(TAG_NAME, name);
contact.put(TAG_EMAIL, email);
contact.put(TAG_PHONE_MOBILE, mobile);
// adding contact to contact list
contactList.add(contact);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
/* if (pDialog.isShowing())
pDialog.dismiss();*/
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
MainActivity.this, contactList,
R.layout.list_item, new String[]{TAG_NAME, TAG_EMAIL,
TAG_PHONE_MOBILE}, new int[]{R.id.name,
R.id.email, R.id.mobile});
setListAdapter(adapter);
}
}
#Override
public void onRefresh() {
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
new GetContacts().execute();
swipeLayout.setRefreshing(false);
}
}, 5000);
}

The only thing you have to do is set adapter like this way and it won't replicate data. It just add new data below older one.
adapter = null;
if (adapter == null) {
adapter = new CustomAdapter(this, arrayList);
listvie.setAdapter(adapter);
}
adapter.notifyDataSetChanged();
Hope it will work.
Thanks. :)

Solution is very simple.
Create ListAdapter before executing AsyncTask with empty Collection
Set adapter for ListView with created adapter
In AsyncTask create local field ArrayList<HashMap<String, String>> localList
Parsed contacts put to localList, not to contactList
After download items, clear Collection by calling contactList.clear();
Add download contacts contactList.addAll(localList);
Call adapter.notifyDataSetChanged();

Android - Get value from HashMap and store to private String[] drinkImages

I am new to Android. I am using Fedor's Lazy Loading List. Is it possible to get all the values from a HashMap (values were retrieved from mysql) and store it to private String[] drinkImages?
String[] drinkImages' values will be passed to adapter Lazy_Adapter.
Or is there any other way to pass the value to Lazy_Adapter?
Code:
Lazy_ListItem.java
public class Lazy_ListItem extends Activity {
ListView list;
Lazy_Adapter adapter;
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> drinksList;
// url to get all products list
private static String url_all_drinks = "http://10.0.2.2/restosnapp/get_all_products.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_DRINKS = "drinks";
private static final String TAG_RID = "rid";
private static final String TAG_DRK_ID = "drk_id";
private static final String TAG_DRK_NAME = "drk_name";
private static final String TAG_DRK_DESC = "drk_desc";
private static final String TAG_DRK_PRICE = "drk_price";
private static final String TAG_DRK_AVAIL = "drk_avail";
private static final String TAG_DRK_IMAGE = "drk_image";
// products JSONArray
JSONArray drinks = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.list_item);
list = (ListView) findViewById(R.id.list);
adapter = new Lazy_Adapter(this, drinkImages);
list.setAdapter(adapter);
// Button b = (Button) findViewById(R.id.button1);
// b.setOnClickListener(listener);
}
#Override
public void onDestroy() {
list.setAdapter(null);
super.onDestroy();
}
/*
* public OnClickListener listener = new OnClickListener() {
*
* #Override public void onClick(View arg0) {
* adapter.imageLoader.clearCache(); adapter.notifyDataSetChanged(); } };
*/
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllProducts extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
/*
* #Override protected void onPreExecute() { super.onPreExecute();
*
* pDialog = new ProgressDialog(Lazy_Adapter.this, Lazy_ListItem.class);
* pDialog.setMessage("Loading drinks. Please wait...");
* pDialog.setIndeterminate(false); pDialog.setCancelable(false);
* pDialog.show();
*
* //final ProgressDialog dialog; // dialog =
* ProgressDialog.show(getActivity, "Title", "Message", true); }
*/
/**
* getting All products from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_drinks, "GET",
params);
// Check your log cat for JSON response
Log.d("All Drinks: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
drinks = json.getJSONArray(TAG_DRINKS);
// looping through All Products
for (int i = 0; i < drinks.length(); i++) {
JSONObject c = drinks.getJSONObject(i);
// Storing each json item in variable
String drk_image = c.getString(TAG_DRK_IMAGE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_DRK_IMAGE, drk_image);
// adding HashList to ArrayList
drinksList.add(map);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
}
private String[] drinkImages = {
"http://webitprojects.com/restaurant/images/drinks/drk_coffee.jpg",
"http://webitprojects.com/restaurant/images/drinks/drk_calamansijuice.jpg",
"http://webitprojects.com/restaurant/images/drinks/drk_blackgulaman.jpg",
"http://webitprojects.com/restaurant/images/drinks/drk_avocadoshake.jpg",
"http://webitprojects.com/restaurant/images/drinks/drk_durianshake.jpg" }; }
Lazy_Adapter.java
public class Lazy_Adapter extends BaseAdapter {
String drk_name, drk_desc, drk_price, drk_avail;
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> drinksList;
// url to get all products list
private static String url_all_drinks = "http://10.0.2.2/restosnapp/get_all_products.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_DRINKS = "drinks";
private static final String TAG_RID = "rid";
private static final String TAG_DRK_ID = "drk_id";
private static final String TAG_DRK_NAME = "drk_name";
private static final String TAG_DRK_DESC = "drk_desc";
private static final String TAG_DRK_PRICE = "drk_price";
private static final String TAG_DRK_AVAIL = "drk_avail";
private static final String TAG_DRK_IMAGE = "drk_image";
// products JSONArray
JSONArray drinks = null;
private Activity activity;
private String[] data;
private static LayoutInflater inflater = null;
public Lazy_ImageLoader imageLoader;
public Lazy_Adapter(Activity a, String[] d) {
activity = a;
data = d;
inflater = (LayoutInflater) activity
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
imageLoader = new Lazy_ImageLoader(activity.getApplicationContext());
// Hashmap for ListView
drinksList = new ArrayList<HashMap<String, String>>();
// Loading products in Background Thread
new LoadAllProducts().execute();
}
public int getCount() {
return data.length;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
// ///
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllProducts extends AsyncTask<String, String, String> {
/**
* getting All products from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_drinks, "GET",
params);
// Check your log cat for JSON response
Log.d("All Drinks: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
drinks = json.getJSONArray(TAG_DRINKS);
// looping through All Products
for (int i = 0; i < drinks.length(); i++) {
JSONObject c = drinks.getJSONObject(i);
// Storing each json item in variable
drk_name = c.getString(TAG_DRK_NAME);
drk_desc = c.getString(TAG_DRK_DESC);
drk_price = c.getString(TAG_DRK_PRICE);
drk_avail = c.getString(TAG_DRK_AVAIL);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_DRK_NAME, drk_name);
map.put(TAG_DRK_DESC, drk_desc);
map.put(TAG_DRK_PRICE, drk_price);
map.put(TAG_DRK_AVAIL, drk_avail);
// adding HashList to ArrayList
drinksList.add(map);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
}
#SuppressWarnings("unused")
public View getView(int position, View convertView, ViewGroup parent) {
View vi = convertView;
if (convertView == null)
vi = inflater.inflate(R.layout.item, null);
for (Map<String, String> menuItem : drinksList) {
ImageView image = (ImageView) vi.findViewById(R.id.image);
imageLoader.DisplayImage(data[position], image);
TextView tvMenuName = (TextView) vi.findViewById(R.id.tvMenuName);
tvMenuName.setText(drinksList.get(position).get(TAG_DRK_NAME));
TextView tvMenuDesc = (TextView) vi.findViewById(R.id.tvMenuDesc);
tvMenuDesc.setText(drinksList.get(position).get(TAG_DRK_DESC));
TextView tvMenuPrice = (TextView) vi.findViewById(R.id.tvMenuPrice);
tvMenuPrice.setText("P"
+ drinksList.get(position).get(TAG_DRK_PRICE));
TextView tvMenuAvail = (TextView) vi.findViewById(R.id.tvMenuAvail);
tvMenuAvail.setText(drinksList.get(position).get(TAG_DRK_AVAIL));
}
return vi;
}}
I hope you can help me. Thank you.

You can access perticular string on loacation with this code. Here i is an index number which may be 0,1,2 etc.
String yourstring = drinksList.get(i).get(TAG_DRK_IMAGE)

String[] drinkImages = (String[]) drinkList.get(0).values().toArray();

Yes, something like this will work .
public static void main(String[] args) {
Map<String, String> hm = new HashMap<String, String>(); // and yes. I am still using java 6 :(
hm.put("a", "a.jpg");
hm.put("b", "b.jpg");
String[] arr = new String[hm.size()];
hm.values().toArray(arr);
for (String s : arr) {
System.out.println(s);
}
}
O/P:
b.jpg
a.jpg

Try to iterate HashMap and build Array from HashMap value :
public String[] getStringArrayFromMap(HashMap<String,String> map){
String[] array = new String[map.size()];
int i=0;
for (String key : map.keySet()) {
array[i++] = map.get(key);
}
return array;
}

JSON data is read but cannot be converted to JSONArray

I'm developing an app which reads JSON data. Json Data is parsed but it is not viewing in the listview. Logcat says about a type mismatch. I'm not that much familiar in Json.
http://api.openweathermap.org/data/2.5/forecast/daily?lat=6.421465&lon=81.332396&cnt=10&mode=json
This is my logcat and code. Please hemp me with this.
org.json.JSONException: Index 1 out of range [0..1)
org.json.JSONArray.get(JSONArray.java:263)
org.json.JSONArray.getString(JSONArray.java:421)
com.is.parsej.ParseJ$GetContacts.doInBackground(ParseJ.java:141)
com.is.parsej.ParseJ$GetContacts.doInBackground(ParseJ.java:1)
android.os.AsyncTask$2.call(AsyncTask.java:287)
java.util.concurrent.FutureTask.run(FutureTask.java:234)
android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
public class ParseJ extends ListActivity {
private ProgressDialog pDialog;
// URL to get contacts JSON
private static String url = "http://api.openweathermap.org/data/2.5/forecast/daily?lat=6.421465&lon=81.332396&cnt=10&mode=json";
// JSON Node names
private static final String TAG_COd = "list"; //edited
private static final String TAG_ID = "dt"; //edited
private static final String TAG_WEATHER = "weather";
private static final String TAG_MAIN = "main";
private static final String TAG_DESC = "description";
private static final String TAG_TEMP = "temp";
private static final String TAG_DAY = "day";
private static final String TAG_MIN = "min";
private static final String TAG_MAX = "max";
private static final String TAG_NIGHT = "night";
private static final String TAG_MORN= "morn";
private static final String TAG_HUMIDITY = "humidity";
// contacts JSONArray
JSONArray contacts = null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_parse_j);
contactList = new ArrayList<HashMap<String, String>>();
ListView lv = getListView();
// Listview on item click listener
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String weather = ((TextView) view.findViewById(R.id.main))
.getText().toString();
String Temp = ((TextView) view.findViewById(R.id.Descrption))
.getText().toString();
String Humidity = ((TextView) view.findViewById(R.id.temp))
.getText().toString();
// Starting single contact activity
Intent in = new Intent(getApplicationContext(),
SingleContactActivity.class);
in.putExtra(TAG_WEATHER, weather);
in.putExtra(TAG_TEMP, Temp);
in.putExtra(TAG_HUMIDITY, Humidity);
startActivity(in);
}
});
// Calling async task to get json
new GetContacts().execute();
}
/**
* Async task class to get json by making HTTP call
* */
private class GetContacts extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(ParseJ.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
#Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
contacts = jsonObj.getJSONArray(TAG_COd);
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
String id = c.getString(TAG_ID);
String humidity = c.getString(TAG_HUMIDITY);
// Phone node is JSON Object
JSONObject temp = c.getJSONObject(TAG_TEMP);
String day = temp.getString(TAG_DAY);
String maxTemp = temp.getString(TAG_MAX);
String minTemp = temp.getString(TAG_MIN);
String morningTemp = temp.getString(TAG_MORN);
//edited
JSONArray weather = c.getJSONArray(TAG_WEATHER);
String main = weather.getString(1);
String desc = weather.getString(2);
// tmp hashmap for single contact
HashMap<String, String> contact = new HashMap<String, String>();
// adding each child node to HashMap key => value
contact.put(TAG_ID, id);
contact.put(TAG_DAY, day);
contact.put(TAG_DESC, desc);
contact.put(TAG_HUMIDITY, humidity);
// adding contact to contact list
contactList.add(contact);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
ParseJ.this, contactList,
R.layout.list_item, new String[] { TAG_DAY, TAG_DESC,
TAG_HUMIDITY }, new int[] { R.id.temp,
R.id.main, R.id.Descrption });
setListAdapter(adapter);
}
}
}

based on your JSON it is just a list of element. Arrays have [ at the beginning and ] at the end. look closely at your JSON you may find some array elements there that has [].
weather only has 1 element
"weather":[{"id":803,"main":"Clouds","description":"broken clouds","icon":"04d"}]
index out of bounds because you are using
JSONArray weather = c.getJSONArray(TAG_WEATHER);
String main = weather.getString(1);
String desc = weather.getString(2);
where there is no 1 and 2 in your json array weather, since the weather seems to have only 1 element put it in another json object
JSONObject weather = c.getJSONArray(TAG_WEATHER).getJSONObject(0);
String main = weather.getString("main");
String desc = weather.getString("description");

JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
contacts = jsonObj.getJSONArray("list");
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
}
change this in your code and let me know, if any issue.

the json is here
{"cod":"200","message":0.2809,"city":{"id":1244926,"name":"Hambantota","coord":{"lon":81.1185,"lat":6.1241},"country":"LK","population":0},"cnt":10,"list":[{"dt":1409896800,"temp":{"day":301.95,"min":300.47,"max":302.12,"night":301.31,"eve":301.87,"morn":300.47},"pressure":1020.63,"humidity":88,"weather":[{"id":803,"main":"Clouds","description":"broken
clouds","icon":"04d"}],"speed":6.47,"deg":243,"clouds":56},{"dt":1409983200,"temp":{"day":301.11,"min":299.62,"max":301.29,"night":299.62,"eve":300.76,"morn":300.13},"pressure":1021.53,"humidity":92,"weather":[{"id":802,"main":"Clouds","description":"scattered
clouds","icon":"03d"}],"speed":6.66,"deg":249,"clouds":48},{"dt":1410069600,"temp":{"day":300.9,"min":299.36,"max":300.9,"night":299.58,"eve":300.2,"morn":299.36},"pressure":1022.25,"humidity":90,"weather":[{"id":803,"main":"Clouds","description":"broken
clouds","icon":"04d"}],"speed":7.21,"deg":242,"clouds":80},{"dt":1410156000,"temp":{"day":299.47,"min":298.71,"max":300.44,"night":299.5,"eve":299.96,"morn":298.71},"pressure":1023.27,"humidity":98,"weather":[{"id":802,"main":"Clouds","description":"scattered
clouds","icon":"03d"}],"speed":5.83,"deg":252,"clouds":44},{"dt":1410242400,"temp":{"day":301.38,"min":297.39,"max":301.38,"night":298.36,"eve":300.82,"morn":297.39},"pressure":1012.02,"humidity":0,"weather":[{"id":500,"main":"Rain","description":"light
rain","icon":"10d"}],"speed":3.87,"deg":250,"clouds":76,"rain":0.38},{"dt":1410328800,"temp":{"day":301.77,"min":297.49,"max":301.77,"night":299.44,"eve":301.13,"morn":297.49},"pressure":1011.84,"humidity":0,"weather":[{"id":500,"main":"Rain","description":"light
rain","icon":"10d"}],"speed":4.88,"deg":259,"clouds":27,"rain":0.82},{"dt":1410415200,"temp":{"day":302.15,"min":299.15,"max":302.15,"night":299.43,"eve":300.52,"morn":299.15},"pressure":1011.1,"humidity":0,"weather":[{"id":500,"main":"Rain","description":"light
rain","icon":"10d"}],"speed":6.3,"deg":257,"clouds":64,"rain":1.82},{"dt":1410501600,"temp":{"day":301.52,"min":299.16,"max":301.52,"night":299.36,"eve":300.59,"morn":299.16},"pressure":1011.05,"humidity":0,"weather":[{"id":500,"main":"Rain","description":"light
rain","icon":"10d"}],"speed":8.05,"deg":257,"clouds":50,"rain":2.38},{"dt":1410588000,"temp":{"day":301.26,"min":298.74,"max":301.26,"night":299.53,"eve":300.43,"morn":298.74},"pressure":1010.43,"humidity":0,"weather":[{"id":500,"main":"Rain","description":"light
rain","icon":"10d"}],"speed":7.69,"deg":258,"clouds":33,"rain":1.34},{"dt":1410674400,"temp":{"day":300.01,"min":298.37,"max":300.01,"night":298.48,"eve":298.37,"morn":298.87},"pressure":1010.17,"humidity":0,"weather":[{"id":501,"main":"Rain","description":"moderate
rain","icon":"10d"}],"speed":8.36,"deg":253,"clouds":55,"rain":8.91}
and then you get object with tag "cod"
contacts = jsonObj.getJSONArray(TAG_COd)
"cod":"200"
you will get "200"
how can "200" be converted to JSONArray?
the array structure is just like this
[{"dt":1409896800},{"dt":1409896800},{"dt":1409896800},{"dt":1409896800}]
starts with "[" and end with "]"

Exception is self Explaining
org.json.JSONException: Value 200 at cod of type java.lang.String cannot be converted to JSONArray
You are converting String to JSONArray here,
contacts = jsonObj.getJSONArray(TAG_COd);
cod is a String while you're converting it to JSONArray
String cod = jsonObj.getJSONString(TAG_COd);

Custom ListView with single choice selection and dynamic data

I'm working on an app that I need to be able to load a list of locations into a ListView, and then let the user select a single location which will then determine the rest of the user's experience down the line.
Currently I have the list of locations being pulled from a JSON request and I can easily display the information into a ListView - the problem I am having though is getting that same list into some form of list that the user can select just one location. I personally have no preference on if it's a radio button list or a spinner. I have been trying various methods for the past week now from tutorials on the net, but I can never get any of them to work with my current method of retrieving and storing the list, so I'm finally at wits end and looking for some guidance. I am extremely new to java/android programming so I know that my lack of experience is probably the most to blame here. So I guess if someone can at least just point me in the right direction so I'm not spinning my wheels on a solution that would require a ton of re-work then I would greatly appreciate it!
Below is my current activity that retrieves the JSON and slaps it into a standard ListView - I have it storing the info into a DB for use further down the app's line.
public class SQLiteJSONParsing extends ListActivity {
private ProgressDialog pDialog;
//////////////////////// JSON URL //////////////////////////
private static String url = "http://my/link/to/json";
//////////////////////// JSON Node Names //////////////////////////
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_CON_POSITION = "con_position";
private static final String TAG_ADDRESS = "address";
private static final String TAG_SUBURB = "suburb";
private static final String TAG_STATE = "state";
private static final String TAG_POSTCODE = "postcode";
private static final String TAG_TELEPHONE = "telephone";
private static final String TAG_EMAIL_TO = "email_to";
//////////////////////// JSON Array //////////////////////////
JSONArray contacts = null;
private DatabaseHelper databaseHelper;
//////////////////////// HashMap ListView //////////////////////////
ArrayList<HashMap<String, String>> locationsList;
///////////////////////// Start onCreate method ////////////////////////////
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.first_launch_options);
databaseHelper = new DatabaseHelper(SQLiteJSONParsing.this);
locationsList = new ArrayList<HashMap<String, String>>();
//////////////////////// Skip Button //////////////////////////
Button cancel = (Button)findViewById(R.id.cancel);
cancel.setOnClickListener(new OnClickListener()
{ public void onClick(View v)
{
Intent locationList = new Intent(SQLiteJSONParsing.this, MainActivity.class);
startActivity(locationList);
finish();
}
});
//////////////////////// Start ASYNC //////////////////////////
new GetLocations().execute();
}
//////////////////////// ASYNC HTTP Call //////////////////////////
private class GetLocations extends AsyncTask<Void, Void, Void> {
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(SQLiteJSONParsing.this);
pDialog.setMessage("Loading Locations...");
pDialog.setCancelable(true);
pDialog.show();
}
//////////////////////// Start Background Service Handler & Load the DB //////////////////////////
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
LocationsFeedServiceHandler sh = new LocationsFeedServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, LocationsFeedServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
//////////////////////// Get the JSON Node Array //////////////////////////
contacts = jsonObj.getJSONArray(TAG_CONTACTS);
//////////////////////// Loop Through the Results //////////////////////////
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String con_position = c.getString(TAG_CON_POSITION);
String address = c.getString(TAG_ADDRESS);
String suburb = c.getString(TAG_SUBURB);
String state = c.getString(TAG_STATE);
String postcode = c.getString(TAG_POSTCODE);
String telephone = c.getString(TAG_TELEPHONE);
String email_to = c.getString(TAG_EMAIL_TO);
//////////////////////// Save Records to DB //////////////////////////
databaseHelper.saveTableRecord(id, name, con_position, address, suburb, state, postcode, telephone, email_to);
//////////////////////// Single Items HashMap //////////////////////////
HashMap<String, String> items = new HashMap<String, String>();
//////////////////////// Add Items to the HashMap //////////////////////////
items.put(TAG_ID, id);
items.put(TAG_NAME, name);
items.put(TAG_CON_POSITION, con_position);
items.put(TAG_ADDRESS, address);
items.put(TAG_SUBURB, suburb);
items.put(TAG_STATE, state);
items.put(TAG_POSTCODE, postcode);
items.put(TAG_TELEPHONE, telephone);
items.put(TAG_EMAIL_TO, email_to);
//////////////////////// Add Items to the LocationsList //////////////////////////
locationsList.add(items);
}
//////////////////////// Capture Exceptions //////////////////////////
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("LocationsFeedServiceHandler", "Couldn't get any data from the url");
}
return null;
}
//////////////////////// Close Progress Dialog //////////////////////////
protected void onPostExecute(Void location_result) {
super.onPostExecute(location_result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
//////////////////////// Update the Parsed JSON into the ListAdapter //////////////////////////
ListAdapter locations_adapter = new SimpleAdapter(
SQLiteJSONParsing.this, locationsList,
R.layout.first_launch_locations_detail,
new String[] { TAG_NAME },
new int[] { R.id.name });
setListAdapter(locations_adapter);
}
}

I used this following example code, which i need to select single item from the listview.
http://amitandroid.blogspot.in/2013/03/android-custon-single-choice-lsitview.html

Develop Reference

The Android operating system is a mobile operating system that was developed by Google (GOOGL?) to be primarily used for touchscreen devices, cell phones, and tablets.

uunable to pass current activity from asynctask - android

use adapter=new LazyAdapter(MainActivity.this, contactList); only this will pass the asynctask class context.

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JSON data is read but cannot be converted to JSONArray

Custom ListView with single choice selection and dynamic data

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