Develop Reference

Parse API Data into TextView

I have a API link that has a json element named title, and I am trying to store that value into a textview. Here is what I have so far in my main activity code that is supposed to display the contained string:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
JSONObject jObject;
try {
jObject = new JSONObject("https://chex-triplebyte.herokuapp.com/api/cats?page=0");
String mResponse = jObject.getString("title");
TextView t = (TextView) findViewById(R.id.title_image);
t.setText(mResponse);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
The API link I provided works so you can see the value title that I am trying to obtain.

try this:
TextView t = (TextView) findViewById(R.id.title_image);
try {
url = new URL("https://chex-triplebyte.herokuapp.com/api/cats?page=0");
urlConnection = (HttpURLConnection) url
.openConnection();
urlConnection.connect();
InputStream in = urlConnection.getInputStream();
reader = new BufferedReader(new InputStreamReader(in));
//InputStreamReader isw = new InputStreamReader(in);
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
String JsonResponse= buffer.toString();
JSONObject jsonobj = new JSONObject(JsonResponse);
JSONArray jarray = jsono.getJSONArray("jsontitle");
for (int i = 0; i < jarray.length(); i++) {
JSONObject object = jarray.getJSONObject(i);
t.setText(object.getString("title"));
}
} catch (JSONException e) {
e.printStackTrace();
}
but you have to make sure you have a correct json format like this:
{jsontitle:[{"title":"Space Keybaord Cat","timestamp":"2017-09-11T04:00:04Z","image_url":"https://triplebyte-cats.s3.amazonaws.com/space.jpg","description":"In space, no one can hear you purr."},{"title":"Jiji","timestamp":"2017-09-11T03:00:04Z","image_url":"https://triplebyte-cats.s3.amazonaws.com/jiji.png","description":"You'd think they'd never seen a girl and a cat on a broom before"},{"title":"Limecat","timestamp":"2017-09-11T02:00:04Z","image_url":"https://triplebyte-cats.s3.amazonaws.com/lime.jpg","description":"Destroyer of Clockspider and his evil followers, Limecat is the one true god."},{"title":"Astronaut Cat","timestamp":"2017-09-11T01:00:04Z","image_url":"https://triplebyte-cats.s3.amazonaws.com/astronaut.jpg","description":"Houston, we have a purroblem"},{"title":"Grumpy Cat","timestamp":"2017-09-11T00:00:04Z","image_url":"https://triplebyte-cats.s3.amazonaws.com/grumpy.jpg","description":"Queen of the RBF"},{"title":"Soviet cat","timestamp":"2017-09-10T23:00:04Z","image_url":"https://triplebyte-cats.s3.amazonaws.com/soviet.jpg","description":"In soviet Russia cat pets you!"},{"title":"Serious Business Cat","timestamp":"2017-09-10T22:00:04Z","image_url":"https://triplebyte-cats.s3.amazonaws.com/serious.jpg","description":"SRSLY GUISE"},{"title":"Sophisticated Cat","timestamp":"2017-09-10T21:00:04Z","image_url":"https://triplebyte-cats.s3.amazonaws.com/sophisticated.PNG","description":"I should buy a boat"},{"title":"Shironeko","timestamp":"2017-09-10T20:00:04Z","image_url":"https://triplebyte-cats.s3.amazonaws.com/shironeko.png","description":"The zen master kitty"},{"title":"Puss in Boots","timestamp":"2017-09-10T19:00:04Z","image_url":"https://triplebyte-cats.s3.amazonaws.com/puss.jpg","description":"Don't you dare do the litter box on me!"}]}

You need to make a network call first parse it to JSONArray first and then get the title from the JSON
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView t = (TextView) findViewById(R.id.title_image);
RequestQueue queue = Volley.newRequestQueue(this);
String url ="https://chex-triplebyte.herokuapp.com/api/cats?page=0";
// Request a string response from the provided URL.
StringRequest stringRequest = new StringRequest(Request.Method.GET, url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
JSONArray jArray;
try {
jArray = new JSONArray(response);
JSONObject jObject = jArray.getJSONObject(0);
String mResponse = jObject.getString("title");
t.setText(mResponse);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
}
});
// Add the request to the RequestQueue.
queue.add(stringRequest);
}
But this will only show the first title in the response array
If you want to show all titles appended then you can loop over the array
JSONArray jArray;
try {
jArray = new JSONArray(response);
String mResponse = "";
for(int i=0 ;i<jArray.length();i++){
JSONObject jObject = jArray.getJSONObject(i);
mResponse += jObject.getString("title")+" ";
}
t.setText(mResponse);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
For using volley you need to include it in dependencies in build.gradle of app
dependencies {
.
.
compile 'com.android.volley:volley:1.0.0'
.
.
}

Try this...
MainActivity.java
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemClickListener {
private String TAG = MainActivity.class.getSimpleName();
private ListView listView;
List<RowItem> rowItems;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
rowItems = new ArrayList<RowItem>();
listView = (ListView) findViewById(R.id.item_list);
new GetList().execute();
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
Toast toast = Toast.makeText(getApplicationContext(),
"Item " + (position + 1) + ": " + rowItems.get(position),
Toast.LENGTH_SHORT);
toast.setGravity(Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL, 0, 0);
toast.show();
}
class GetList extends AsyncTask<Void, Void, List<RowItem>> {
#Override
protected void onPreExecute() {
super.onPreExecute();
Toast.makeText(MainActivity.this, "Json Data is downloading", Toast.LENGTH_LONG).show();
}
#Override
protected List<RowItem> doInBackground(Void... arg0) {
HttpHandler sh = new HttpHandler();
// Making a request to url and getting response
String url = "https://chex-triplebyte.herokuapp.com/api/cats?page=0";
String jsonStr = sh.makeServiceCall(url);
Log.e(TAG, "Response from url: " + jsonStr);
if (jsonStr != null) {
try {
JSONArray list = new JSONArray(jsonStr);
for (int i = 0; i < list.length(); i++) {
JSONObject c = list.getJSONObject(i);
String title = c.getString("title");
String timestamp = c.getString("timestamp");
String image_url = c.getString("image_url");
String description = c.getString("description");
RowItem item = new RowItem();
item.setTitle(title);
item.setTimestamp(timestamp);
item.setImageUrl(image_url);
item.setDescription(description);
rowItems.add(item);
}
} catch (final JSONException e) {
Log.e(TAG, "Json parsing error: " + e.getMessage());
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(getApplicationContext(),
"Json parsing error: " + e.getMessage(),
Toast.LENGTH_LONG).show();
}
});
}
} else {
Log.e(TAG, "Couldn't get json from server.");
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(getApplicationContext(),
"Couldn't get json from server. Check LogCat for possible errors!",
Toast.LENGTH_LONG).show();
}
});
}
return rowItems;
}
#Override
protected void onPostExecute(List<RowItem> rowItems) {
super.onPostExecute(rowItems);
if (rowItems != null) {
CustomListViewAdapter adapter = new CustomListViewAdapter(MainActivity.this, R.layout.list_item, rowItems);
listView.setAdapter(adapter);
}
}
}
}
CustomListViewAdapter.java
public class CustomListViewAdapter extends ArrayAdapter<RowItem> {
private Context context;
public CustomListViewAdapter(Context context, int resourceId,
List<RowItem> items) {
super(context, resourceId, items);
this.context = context;
}
/*private view holder class*/
private class ViewHolder {
ImageView imageView;
TextView txtTitle;
TextView txtDesc;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
RowItem rowItem = getItem(position);
LayoutInflater mInflater = (LayoutInflater) context
.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
if (convertView == null) {
convertView = mInflater.inflate(R.layout.list_item, null);
holder = new ViewHolder();
holder.txtDesc = (TextView) convertView.findViewById(R.id.description);
holder.txtTitle = (TextView) convertView.findViewById(R.id.title);
holder.imageView = (ImageView) convertView.findViewById(R.id.preview);
convertView.setTag(holder);
} else
holder = (ViewHolder) convertView.getTag();
holder.txtDesc.setText(rowItem.getDescription());
holder.txtTitle.setText(rowItem.getTitle());
String url = rowItem.getImageUrl();
DownloadImageTask downloadImageTask = new DownloadImageTask(holder.imageView);
downloadImageTask.execute(url);
return convertView;
}
private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
ImageView bmImage;
public DownloadImageTask(ImageView bmImage) {
this.bmImage = bmImage;
}
protected Bitmap doInBackground(String... urls) {
String urldisplay = urls[0];
Bitmap mIcon11 = null;
try {
InputStream in = new java.net.URL(urldisplay).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return mIcon11;
}
protected void onPostExecute(Bitmap result) {
bmImage.setImageBitmap(result);
}
}
}
RowItem.java
public class RowItem {
private String title;
private String timestamp;
private String imageUrl;
private String description;
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getTimestamp() {
return timestamp;
}
public void setTimestamp(String timestamp) {
this.timestamp = timestamp;
}
public String getImageUrl() {
return imageUrl;
}
public void setImageUrl(String imageUrl) {
this.imageUrl = imageUrl;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}
list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/linearLayout2">
<ImageView
android:id="#+id/preview"
android:layout_width="80dp"
android:layout_height="80dp"
app:srcCompat="#mipmap/ic_launcher"
android:contentDescription="#string/app_name" />
<TextView
android:id="#+id/title"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="16dp"
android:text="#string/app_name"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="#+id/preview"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/description"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:text="#string/app_name"
app:layout_constraintBottom_toBottomOf="#+id/preview"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="#+id/preview"
app:layout_constraintTop_toBottomOf="#+id/title" />
</android.support.constraint.ConstraintLayout>
HttpHandler.java
public class HttpHandler {
private static final String TAG = HttpHandler.class.getSimpleName();
public HttpHandler() {
}
public String makeServiceCall(String reqUrl) {
String response = null;
try {
URL url = new URL(reqUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
// read the response
InputStream in = new BufferedInputStream(conn.getInputStream());
response = convertStreamToString(in);
} catch (MalformedURLException e) {
Log.e(TAG, "MalformedURLException: " + e.getMessage());
} catch (ProtocolException e) {
Log.e(TAG, "ProtocolException: " + e.getMessage());
} catch (IOException e) {
Log.e(TAG, "IOException: " + e.getMessage());
} catch (Exception e) {
Log.e(TAG, "Exception: " + e.getMessage());
}
return response;
}
private String convertStreamToString(InputStream is) {
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line;
try {
while ((line = reader.readLine()) != null) {
sb.append(line).append('\n');
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}
}
activity_list.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:id="#+id/item_list"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
Note:
item_list.xml has ConstraintLayout implementation.
Result:

Run your request and receive new data Json

I have a problem. When I do a query in the stream, I have downloaded the data from the URL, everything works. But when I call AsynsTask example by pressing doInBackground() method that returns the same data, but they are updated on the URL. And they will not be updated as long as the program is restarted.
#Override
protected String doInBackground(Void... params) {
try {
URL url = new URL("data.php?"+new Random().nextInt(200));
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
jSON_R = buffer.toString();
} catch (Exception e) {
e.printStackTrace();
}
return jSON_R;
}
All code
public class ParseTask extends AsyncTask<Void, Void, String> {
int intRow = 0;
String jSON_R = "";
private List<User> movieList;
Activity act;
ListView list;
LAdapter adapter;
boolean Unique = true;
public ParseTask (Activity act){
this.act = act;
}
#Override
protected String doInBackground(Void... params) {
try {
URL url = new URL("data.php?"+new Random().nextInt(200));
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
jSON_R = buffer.toString();
} catch (Exception e) {
e.printStackTrace();
}
return jSON_R;
}
#Override
protected void onPostExecute(String strJson) {
super.onPostExecute(strJson);
list = (ListView) act.findViewById(R.id.listVew);
Button b = (Button) act.findViewById(R.id.refresh);
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//To do
}
});
movieList = new ArrayList<>();
adapter = new LAdapter(act, movieList);
list.setAdapter(adapter);
try {
JSONObject dataJsonObj = new JSONObject(strJson);
JSONArray jsa = dataJsonObj.getJSONArray("data");
for (int i = 0; i < jsa.length(); i++) {
JSONObject data1 = chat.getJSONObject(i);
String mes = data1.getString("mes1");
String mes2 = data1.getString("mes2");
String mes3 = data1.getString("mes3");
User m = new User(mes, mes2, mes3);
movieList.add(0, m);
}
adapter.notifyDataSetChanged();
intRow = jsa.length();
} catch (JSONException e) {
e.printStackTrace();
}
list.setOnScrollListener(new AbsListView.OnScrollListener() {
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {}
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
if (firstVisibleItem > 1){
Unique = false;
}else{
Unique = true;
}
}
});
Thread thread = new Thread() {
#Override
public void run() {
try {
while (true){
sleep(5000);
if (Unique){
act.runOnUiThread(new Runnable() {
#Override
public void run() {
Update();
}
});
}
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
thread.start();
}
private void Update(){
try {
JSONObject dataJsonObj = new JSONObject(strJson);
JSONArray jsa = dataJsonObj.getJSONArray("data");
for (int i = 0; i < jsa.length(); i++) {
JSONObject data1 = chat.getJSONObject(i);
String mes = data1.getString("mes1");
String mes2 = data1.getString("mes2");
String mes3 = data1.getString("mes3");
User m = new User(mes, mes2, mes3);
movieList.add(0, m);
}
adapter.notifyDataSetChanged();
intRow = jsa.length();
} catch (JSONException e) {
e.printStackTrace();
}
adapter.notifyDataSetChanged();
}
}
Calling the object in such a way
new ParseTask(getActivity()).execute();

Close the connection.
I mean use (better) reader.close() or inputStream.close()
Or try jsoup library https://jsoup.org/

Parsing multiple JsonObject and JsonArray

I have some issues with using multiple jsonobjects I want to use "posts" and "attachments" jsonobjects.
but I tried to use the line and another for loop for attachments jsonObject but it doesnt work.
String postInfo = jsonObject.getString("attachments");
My Json looks like this:
{"posts":[
{"title":"Title","content":"Post content"}
]
}
{"attachments":[
{"url":"http://www.something.com"}
]
}
Java code:
public class NewsActivity extends FragmentActivity {
ViewPager viewPager;
int category;
ArrayList titleList;
ArrayList postList;
ArrayList imgList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_news);
Intent i = getIntent();
category=i.getIntExtra("locationInfo",-1);
try {
String encodedCatName = URLEncoder.encode(Integer.toString(category), "UTF-8");
DownloadTask task = new DownloadTask();
task.execute("http://www.something.co/api/get_category_posts/?id=" + encodedCatName);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
// Toast.makeText(getApplicationContext(), "Could not find weather", Toast.LENGTH_LONG);
}
}
public class DownloadTask extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... urls) {
postList = new ArrayList();
titleList = new ArrayList();
imgList = new ArrayList();
String result = "";
URL url;
HttpURLConnection urlConnection = null;
try {
url = new URL(urls[0]);
urlConnection = (HttpURLConnection) url.openConnection();
InputStream in = urlConnection.getInputStream();
InputStreamReader reader = new InputStreamReader(in);
int data = reader.read();
while (data != -1) {
char current = (char) data;
result += current;
data = reader.read();
}
return result;
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "Could not find", Toast.LENGTH_LONG);
}
return null;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
try {
String message = "";
JSONObject jsonObject = new JSONObject(result);
String postInfo = jsonObject.getString("posts");
Log.i("Content", postInfo);
JSONArray arr = new JSONArray(postInfo);
JSONArray attachments = jsonObject.getJSONArray("attachments");
for(int i=0; i< attachments.length(); i++){
String url = "";
url = attachments.getJSONObject(i).getString("url");
imgList.add(url);
}
for (int i = 0; i < arr.length(); i++) {
JSONObject jsonPart = arr.getJSONObject(i);
String title = "";
String post = "";
title = jsonPart.getString("title");
post = jsonPart.getString("content");
if (title != "" && post != "") {
message += title + ": " + post + "\r\n";
titleList.add(title);
postList.add(post);
}
}
viewPager = (ViewPager) findViewById(R.id.view_pager);
SwipeAdapter swipeAdapter = new SwipeAdapter(getSupportFragmentManager(),category,titleList,postList,imgList);
viewPager.setAdapter(swipeAdapter);
} catch (JSONException e) {
Toast.makeText(getApplicationContext(), "Could not find ", Toast.LENGTH_LONG);
}
}
}
}

The type related to 'attachments' is an array, therefore you should call something like:
JSONArray attachments = jsonObject.getJSONArray("attachments")
for(int i=0; i< attachments.length(); i++){
attachments.getJSONObject(i).getString("url");
}

Results not showing in the ListView Android

I've been working on an android app ... I am stuck at a point ... after getting the JSON data from the internet I am having trouble to show it in the ListView ... Below is my code ...
public class MainListActivityFragment extends Fragment {
protected String[] mBlogPostTitles;
protected JSONObject mBlogData;
public static final String LOG_TAG = MainListActivityFragment.class.getSimpleName();
public static ArrayAdapter<String> titleAdapter;
public MainListActivityFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main_list, container, false);
if(isNetworkAvailable()) {
GetBlogPost getBlogPost = new GetBlogPost();
getBlogPost.execute();
} else {
Toast.makeText(getContext(),"No Network Available", Toast.LENGTH_LONG).show();
}
List<String> blogTitles = new ArrayList<>(Arrays.asList(mBlogPostTitles));
titleAdapter = new ArrayAdapter<>(
getActivity(),
R.layout.name_lst_view,
R.id.name_list_view_textview,
blogTitles
);
ListView listView = (ListView) rootView.findViewById(R.id.listview_name);
listView.setAdapter(titleAdapter);
return rootView;
}
private boolean isNetworkAvailable() {
ConnectivityManager manager = (ConnectivityManager) getActivity().getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = manager.getActiveNetworkInfo();
boolean isAvailable = false;
if (networkInfo != null && networkInfo.isConnected()){
isAvailable = true;
}
return isAvailable;
}
private void updateList() {
if(mBlogData == null){
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle("Oopps");
builder.setMessage("There was an error accessing the blog ...");
builder.setPositiveButton(android.R.string.ok, null);
AlertDialog dialog = builder.create();
dialog.show();
}else {
try {
JSONArray jsonPosts = mBlogData.getJSONArray("posts");
mBlogPostTitles = new String[jsonPosts.length()];
for (int i = 0; i < jsonPosts.length(); i++){
JSONObject post = jsonPosts.getJSONObject(i);
String title = post.getString("title");
title = Html.fromHtml(title).toString();
mBlogPostTitles[i] = title;
}
} catch (JSONException e) {
Log.e(LOG_TAG,"Exception Caught: ",e);
}
}
}
public class GetBlogPost extends AsyncTask<Object, Void, JSONObject> {
public final int NUMBER_OF_POSTS = 5;
int responseCode = -1;
JSONObject jsonResponse = null;
#Override
protected JSONObject doInBackground(Object... params) {
try {
URL blogFeedUrl = new URL("http://www.example.com/api/get_category_posts/?slug=americancuisines&count="+NUMBER_OF_POSTS);
HttpURLConnection connection = (HttpURLConnection) blogFeedUrl.openConnection();
connection.setRequestMethod("GET");
connection.connect();
responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK){
InputStream inputStream = connection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
// Nothing to do.
return null;
}
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
// Since it's JSON, adding a newline isn't necessary (it won't affect parsing)
// But it does make debugging a *lot* easier if you print out the completed
// buffer for debugging.
buffer.append(line + "\n");
}
if (buffer.length() == 0) {
// Stream was empty. No point in parsing.
return null;
}
String blogDataJsonStr = buffer.toString();
jsonResponse = new JSONObject(blogDataJsonStr);
}else {
Log.i(LOG_TAG, "Unsuccessful HTTP Response Code: " + responseCode);
}
}
catch (MalformedURLException e){
Log.e(LOG_TAG,"Exception Caught: ",e);
}
catch (IOException e) {
Log.e(LOG_TAG, "IO Exception Caught: ",e);
}
catch (Exception e) {
Log.e(LOG_TAG,"Exception Caught: ",e);
}
return jsonResponse;
}
#Override
protected void onPostExecute(JSONObject result) {
super.onPostExecute(result);
mBlogData = result;
updateList();
}
}
}
From the above code you can see that i am getting that data through doInBackground method of AsyncTask ... Data is coming through perfectly as I can see through the logcat ... The issue is somewhere in this method which I can't seem to figure out ..
private void updateList() {
if(mBlogData == null){
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle("Oopps");
builder.setMessage("There was an error accessing the blog ...");
builder.setPositiveButton(android.R.string.ok, null);
AlertDialog dialog = builder.create();
dialog.show();
}else {
try {
JSONArray jsonPosts = mBlogData.getJSONArray("posts");
mBlogPostTitles = new String[jsonPosts.length()];
for (int i = 0; i < jsonPosts.length(); i++){
JSONObject post = jsonPosts.getJSONObject(i);
String title = post.getString("title");
title = Html.fromHtml(title).toString();
mBlogPostTitles[i] = title;
}
} catch (JSONException e) {
Log.e(LOG_TAG,"Exception Caught: ",e);
}
}
}
The above method is called in onPostExecute I mean if i print to logcat within this method I can see the results being printed but when I try to show those results in the onCreateView method results don't show up not even in the logcat ... Any help will be appreciated ... Thanks

Change your code as following:
public class MainListActivityFragment extends Fragment {
protected String[] mBlogPostTitles;
protected JSONObject mBlogData;
public static final String LOG_TAG = MainListActivityFragment.class.getSimpleName();
public static ArrayAdapter<String> titleAdapter;
ListView listView;
public MainListActivityFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main_list, container, false);
listView = (ListView) rootView.findViewById(R.id.listview_name);
if(isNetworkAvailable()) {
GetBlogPost getBlogPost = new GetBlogPost();
getBlogPost.execute();
} else {
Toast.makeText(getContext(),"No Network Available", Toast.LENGTH_LONG).show();
}
return rootView;
}
private void updateList() {
if(mBlogData == null){
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle("Oopps");
builder.setMessage("There was an error accessing the blog ...");
builder.setPositiveButton(android.R.string.ok, null);
AlertDialog dialog = builder.create();
dialog.show();
}else {
try {
JSONArray jsonPosts = mBlogData.getJSONArray("posts");
mBlogPostTitles = new String[jsonPosts.length()];
for (int i = 0; i < jsonPosts.length(); i++){
JSONObject post = jsonPosts.getJSONObject(i);
String title = post.getString("title");
title = Html.fromHtml(title).toString();
mBlogPostTitles[i] = title;
}
} catch (JSONException e) {
Log.e(LOG_TAG,"Exception Caught: ",e);
}
}
}
public class GetBlogPost extends AsyncTask<Object, Void, JSONObject> {
public final int NUMBER_OF_POSTS = 5;
int responseCode = -1;
JSONObject jsonResponse = null;
#Override
protected JSONObject doInBackground(Object... params) {
try {
URL blogFeedUrl = new URL("http://www.example.com/api/get_category_posts/?slug=americancuisines&count="+NUMBER_OF_POSTS);
HttpURLConnection connection = (HttpURLConnection) blogFeedUrl.openConnection();
connection.setRequestMethod("GET");
connection.connect();
responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK){
InputStream inputStream = connection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
// Nothing to do.
return null;
}
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
// Since it's JSON, adding a newline isn't necessary (it won't affect parsing)
// But it does make debugging a *lot* easier if you print out the completed
// buffer for debugging.
buffer.append(line + "\n");
}
if (buffer.length() == 0) {
// Stream was empty. No point in parsing.
return null;
}
String blogDataJsonStr = buffer.toString();
jsonResponse = new JSONObject(blogDataJsonStr);
}else {
Log.i(LOG_TAG, "Unsuccessful HTTP Response Code: " + responseCode);
}
}
catch (MalformedURLException e){
Log.e(LOG_TAG,"Exception Caught: ",e);
}
catch (IOException e) {
Log.e(LOG_TAG, "IO Exception Caught: ",e);
}
catch (Exception e) {
Log.e(LOG_TAG,"Exception Caught: ",e);
}
return jsonResponse;
}
#Override
protected void onPostExecute(JSONObject result) {
super.onPostExecute(result);
mBlogData = result;
updateList();
List<String> blogTitles = new ArrayList<>(Arrays.asList(mBlogPostTitles));
titleAdapter = new ArrayAdapter<String>(
getActivity(),
R.layout.name_list_view,
R.id.name_list_view_textview,
blogTitles
);
listView.setAdapter(titleAdapter);
}
}
}

Use same array list in both update and initialize so globally declare a single array list and update it in updateList() method,
Try like this,
try {
JSONArray jsonPosts = mBlogData.getJSONArray("posts");
mBlogPostTitles = new String[jsonPosts.length()];//remove this and use the
//same as you are using in adapter
for (int i = 0; i < jsonPosts.length(); i++){
JSONObject post = jsonPosts.getJSONObject(i);
String title = post.getString("title");
title = Html.fromHtml(title).toString();
mBlogPostTitles[i] = title;
}
titleAdapter.notifyDataSetChanged();//here
} catch (JSONException e) {
Log.e(LOG_TAG,"Exception Caught: ",e);
}
OR even you can use in onPostExecute
#Override
protected void onPostExecute(JSONObject result) {
super.onPostExecute(result);
mBlogData = result;
updateList();
titleAdapter.notifyDataSetChanged();//here
}

find the listview : ListView listView = (ListView) rootView.findViewById(R.id.listview_name); before calling
GetBlogPost getBlogPost = new GetBlogPost();
getBlogPost.execute();
and put this line listView.setAdapter(titleAdapter); in your onPostExecute method.

Android GUI does not show up

I am currently making an app for android and I have a problem where the UI on a new activity that I start from the main one does not show up. I have no idea what the problem is.
Here is my second activity's layout xml file:
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/TableLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.tabcards.android.Search" >
<TableRow
android:id="#+id/tableRow1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1" >
<ScrollView
android:id="#+id/scrollView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="5dp"
>
<TableLayout
android:id="#+id/tableScrollView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:stretchColumns="yes"
android:padding="5dp"
android:background="#color/gray">
</TableLayout>
</ScrollView>
</TableRow>
Here is my acitiviy's code:
public class Search extends ActionBarActivity {
TableLayout tableScrollView;
String[] JSONExceptions = { "type", "em", "user_id", "id", "profilepic", "bg"};
String value;
JSONObject jObject;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search);
Bundle extras = getIntent().getExtras();
if (extras != null) {
value = extras.getString("id");
}
System.out.println(value);
tableScrollView = (TableLayout) findViewById(R.id.tableScrollView);
Thread thread = new Thread(new Runnable() {
#Override
public void run() {
try {
jObject = getJson("http://www.tabcards.com/req/androidapi/L2o30H8JlFMtFYHW3KLxkts20ztc5Be6Z6m6v315/json/"
+ value);
} catch (Exception e) {
e.printStackTrace();
}
}
});
thread.start();
try {
thread.join();
} catch (InterruptedException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
new Thread(new Runnable() {
#Override
public void run() {
try {
createUI(jObject);
} catch (JSONException e) {
e.printStackTrace();
}
}
});
System.out.println("complete");
}
private void createUI(JSONObject jObject) throws JSONException {
Iterator<?> keys = jObject.keys();
int absIndex = 0;
while( keys.hasNext() ){
String key = (String)keys.next();
if(!contains2(JSONExceptions , jObject.get(key))){
String value = jObject.getString(key);
System.out.println("level 1");
if(value!="") {
insertElement(key + " : " + value, absIndex++);
}
}
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.search, menu);
return true;
}
private void insertElement(String data, int i) {
LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View newRow = inflater.inflate(R.layout.row, null, false);
newRow.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT));
TextView dataTextView = (TextView) newRow
.findViewById(R.id.rowTextView);
dataTextView.setText(data);
System.out.println(dataTextView.getText().toString());
tableScrollView.addView(newRow, i);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
private InputStream downloadUrl(String urlString) throws IOException {
URL url = new URL(urlString);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(10000 /* milliseconds */);
conn.setConnectTimeout(15000 /* milliseconds */);
conn.setRequestMethod("GET");
conn.setDoInput(true);
// Starts the query
conn.connect();
return conn.getInputStream();
}
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
public static JSONObject getJson(String url){
InputStream is = null;
String result = "";
JSONObject jsonObject = null;
// HTTP
try {
HttpClient httpclient = new DefaultHttpClient(); // for port 80 requests!
HttpPost httppost = new HttpPost(url);
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch(Exception e) {
return null;
}
// Read response to string
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"utf-8"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
System.out.println(line);
}
is.close();
result = sb.toString().replace("[", "");
} catch(Exception e) {
return null;
}
// Convert string to object
try {
jsonObject = new JSONObject(result.replace("]", ""));
} catch(JSONException e) {
return null;
}
return jsonObject;
}
This is how I am creating the activity:
Intent i = new Intent(getApplicationContext(), Search.class);
i.putExtra("id",searchEditText.getText().toString());
startActivity(i);
Tell me if you need any more info.

problem:
thread.join();
That problem is dreadlock you are waiting for thread to be done executing, which will put your UI thread to the Blocking state like Thread.Sleep() thus UI thread is waiting for your request to be done executing before it can display the layout in the screen.
from documentation:
Like sleep, join responds to an interrupt by exiting with an InterruptedException.
solution:
Use only one thread which will still wait for the request(createUI) and executes your createUI method after.
Thread thread = new Thread(new Runnable() {
#Override
public void run() {
try {
jObject = getJson("http://www.tabcards.com/req/androidapi/L2o30H8JlFMtFYHW3KLxkts20ztc5Be6Z6m6v315/json/"
+ value);
createUI(jObject);
} catch (Exception e) {
e.printStackTrace();
}
}
});
thread.start();