Develop Reference

Getting Data from JSON?

I want to get the username from this
Json url.
I have this code but it doesn't let me get the data saying
Json parsing error
Here is the code:
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();
}
}
MainActivity.java
public class MainActivity extends AppCompatActivity {
private String TAG = MainActivity.class.getSimpleName();
private ProgressDialog pDialog;
private ListView lv;
// URL to get contacts JSON
private static String url = "https://someLink";
ArrayList<HashMap<String, String>> contactList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
contactList = new ArrayList<>();
lv = (ListView) findViewById(R.id.list);
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) {
HttpHandler sh = new HttpHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url);
Log.e(TAG, "Response from url: " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
JSONArray contacts = jsonObj.getJSONArray("");
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
String name = c.getString("username");
// tmp hash map for single contact
HashMap<String, String> contact = new HashMap<>();
// adding each child node to HashMap key => value
contact.put("username", name);
// adding contact to contact list
contactList.add(contact);
}
} 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 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[]{"username"}, new int[]{R.id.name});
lv.setAdapter(adapter);
}
}
}
This is an example i found on google and tried to change it a bit in my needs.I've put an empty JsonArray.I also tried other examples but i can't understand what is going wrong.
**
> New question
If my url is like this?What is the difference with the other?
**

You don't have an array to parse in the output. Your URL giving you an Object. Your code should be something like this
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
String name = jsonObj.getString("username");
//... now use the whereever you want
}
catch (final JSONException e) {
//... put your error log
}

Please edit your code in MainActivity to get the username from json string as follows :
if(jsonStr!=null)
{
JSONObject jsonObj = new JSONObject(jsonStr);
if(jsonObj !=null)
{
String name = jsonObj .getString("username");
}
}

i suggest you to use this one.
public class HttpGetResources extends AsyncTask<String, Void, Object> {
#SuppressLint("StaticFieldLeak")
private ProgressBar progressBar;
private static final String RAW_DATE_FORMAT = "yyyy-MM-dd'T'HH:mm:ss.SSSz";
private String urlString;
private String apiName;
private Class Response_Class;
private static final Gson GSON = new GsonBuilder().setDateFormat(RAW_DATE_FORMAT).create();
private Context context;
public HttpGetResources(Context context,Class Response_Class, String apiName, String urlString) {
this.Response_Class = Response_Class;
this.apiName = apiName;
this.urlString = urlString;
this.context=context;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected void onPostExecute(Object response) {
super.onPostExecute(response);
}
HttpURLConnection conn = null;
OutputStreamWriter out = null;
Object result = null;
BufferedReader buffer = null;
final ExecutorService executor = Executors.newCachedThreadPool(Executors.defaultThreadFactory());
static public Future<Object> future;
#SuppressWarnings("unchecked")
#Override
protected Object doInBackground(final String... params) {
// JsonObject res=null;
future = executor.submit(new Callable<Object>() {
#Override
public Object call() throws IOException {
try {
URL url = new URL(urlString + apiName);
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json;charset=UTF-8");
conn.setConnectTimeout(3000);
conn.setReadTimeout(15000);
conn.setDoInput(true);
conn.setDoOutput(true);
out = new OutputStreamWriter(conn.getOutputStream());
out.write(params[0]);
out.flush();
out.close(); out=null;
buffer = new BufferedReader(new InputStreamReader(conn.getInputStream()));
// res= GSON.fromJson(buffer, JsonObject.class);
// result = new Gson().fromJson(res.toString(), Response_Class);
result = GSON.fromJson(buffer, Response_Class);
buffer.close(); buffer=null;
// result = new Gson().fromJson(res.toString(), Response_Class);
} catch (Exception e) {
//
} finally {
if (buffer!=null) {
try {
buffer.close();
} catch (Exception e) { //
}
}
if (out != null) {
try {
out.close();
} catch (Exception e) { //
}
}
if (conn != null) {
conn.disconnect();
}
}
return result;
}
});
try {
result = future.get(10, TimeUnit.SECONDS);
} catch (Exception ignored) {
}
return result;
}
}
--and call method--
public synchronized Object HttpGetRes(final Object REQUEST_CLASS, final Class RESPONSE_CLASS, final String
API_NAME, final String URL) {
if(isNetworkAvailable()) {
response = null;
try {
Log.e(API_NAME, "url: " + URL);
Log.e(REQUEST_CLASS.getClass().getSimpleName(), new Gson().toJson(REQUEST_CLASS));
HttpGetResources resource = new HttpGetResources(BaseContext,RESPONSE_CLASS, API_NAME,
URL);
response = resource.execute(new Gson().toJson(REQUEST_CLASS)).get();
} catch (InterruptedException | ExecutionException e) {
e.printStackTrace();
}
if (response != null) {
String x = new Gson().toJson(response);
Log.e(RESPONSE_CLASS.getSimpleName(), x);
return response;
} else {
}
}
return null;
}

Try to use GSON library in the future, it will auto convert the JSON object to a java object automatically for you. This will be useful to avoid parsing complex JSON objects or JSON arrays. https://github.com/google/gson

My application is working on emulator but not on real devices

i am using simple asynctask function for getting values from mysql database through json.it was working fine with emulator but if i am trying from the mobile i am getting error. like Java.lang.NullPointerExceprtion:Attempt to invke virtual metho 'java.lang.string.java.lang.stringbuilder.toString() on a null object reference.
I tried with new project but result is same. this application is not working in all the devices except emulator. can you help me on this.
My Code is -
public class MainActivity extends AppCompatActivity {
private static final String Latest_Products7 = "Questions";
JSONArray productsArray7 = null;
public static final int CONNECTION_TIMEOUT7=100000;
public static final int READ_TIMEOUT7=150000;
HashMap<String,ArrayList<WorldPopulation>> hasmap = new HashMap<String,ArrayList<WorldPopulation>>();
ArrayList<WorldPopulation> arraylist7 = null;
StringBuilder result7;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new AsyncLogin7().execute();
}
private class AsyncLogin7 extends AsyncTask<String, String, StringBuilder> {
ProgressDialog pdLoading = new ProgressDialog(MainActivity.this);
HttpURLConnection conn7;
URL url7 = null;
#Override
protected void onPreExecute() {
super.onPreExecute();
pdLoading.setMessage("\tLoading...");
pdLoading.setCancelable(false);
pdLoading.show();
}
#Override
protected StringBuilder doInBackground(String... params) {
try {
// Enter URL address where your php file resides
url7 = new URL("http:/Samplesite/****/somephp.php");
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
// Setup HttpURLConnection class to send and receive data from php and mysql
conn7 = (HttpURLConnection)url7.openConnection();
conn7.setReadTimeout(READ_TIMEOUT7);
conn7.setConnectTimeout(CONNECTION_TIMEOUT7);
conn7.setRequestMethod("POST");
// setDoInput and setDoOutput method depict handling of both send and receive
conn7.setDoInput(true);
conn7.setDoOutput(true);
// Append parameters to URL
Uri.Builder builder7 = new Uri.Builder().appendQueryParameter("reg_id", "hai") ;
String query7 = builder7.build().getEncodedQuery();
// Open connection for sending data
OutputStream os7 = conn7.getOutputStream();
BufferedWriter writer7 = new BufferedWriter(new OutputStreamWriter(os7, "UTF-8"));
writer7.write(query7);
writer7.flush();
writer7.close();
os7.close();
conn7.connect();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
int response_code7 = conn7.getResponseCode();
// Check if successful connection made
if (response_code7 == HttpURLConnection.HTTP_OK) {
// Read data sent from server
InputStream input7 = conn7.getInputStream();
BufferedReader reader7 = new BufferedReader(new InputStreamReader(input7));
result7 = new StringBuilder();
String line7;
while ((line7 = reader7.readLine()) != null) {
result7.append(line7);
}
// Pass data to onPostExecute method
}
} catch (IOException e) {
e.printStackTrace();
} finally {
conn7.disconnect();
}
return result7;
}
#Override
protected void onPostExecute(StringBuilder result7) {
super.onPostExecute(result7);
Log.e("dai",result7.toString());
Toast.makeText(MainActivity.this,result7.toString(),Toast.LENGTH_LONG).show();
pdLoading.dismiss();
/* Intent intnt = new Intent(Checklist_activity.this,Task_main.class);
intnt.putExtra("task",hasmap);
startActivity(intnt);*/
}
}
}

Change
try {
int response_code7 = conn7.getResponseCode();
// Check if successful connection made
if (response_code7 == HttpURLConnection.HTTP_OK) {
// Read data sent from server
InputStream input7 = conn7.getInputStream();
BufferedReader reader7 = new BufferedReader(new InputStreamReader(input7));
result7 = new StringBuilder();
String line7;
while ((line7 = reader7.readLine()) != null) {
result7.append(line7);
}
// Pass data to onPostExecute method
}
} catch (IOException e) {
e.printStackTrace();
} finally {
conn7.disconnect();
}
return result7;
To
try {
int response_code7 = conn7.getResponseCode();
result7 = new StringBuilder();
// Check if successful connection made
if (response_code7 == HttpURLConnection.HTTP_OK) {
// Read data sent from server
InputStream input7 = conn7.getInputStream();
BufferedReader reader7 = new BufferedReader(new InputStreamReader(input7));
String line7;
while ((line7 = reader7.readLine()) != null) {
result7.append(line7);
}
// Pass data to onPostExecute method
}
} catch (IOException e) {
e.printStackTrace();
} finally {
conn7.disconnect();
}
return result7;

Try something like this
Log.e("dai",MainActivity.this.result7.toString());
Toast.makeText(MainActivity.this,MainActivity.this.result7.toString(),Toast.LENGTH_LONG).show();
OR
#Override
protected void onPostExecute(StringBuilder result) {
super.onPostExecute(result);
Log.e("dai",result.toString());
Toast.makeText(MainActivity.this,result.toString(),Toast.LENGTH_LONG).show();
pdLoading.dismiss();
/* Intent intnt = new Intent(Checklist_activity.this,Task_main.class);
intnt.putExtra("task",hasmap);
startActivity(intnt);*/
}
}

while navigating to the next page from login page, blank screen appears

I have integrated a webservice and after integrating it goes to the next page.
But the problem is while navigating to from login page to next page, it is showing blank screen and I do not understand what's the problem.
Kindly Help!!
Thanks in advance.
Here is my code
public class Mobile_Number_Activity extends Activity {
private EditText ed_Mobile_Number;
private Button btnSubmit;
private TextView Hyperlink;
private ProgressDialog pDialog;
private JSONObject json;
private int success = 0;
private String path = "xxx";
private String strMobileNumber = "";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mobile_number);
ed_Mobile_Number = (EditText) findViewById(R.id.ed_Mobile_Number);
btnSubmit = (Button) findViewById(R.id.btn_mobile_submit);
btnSubmit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v)
{
if (!ed_Mobile_Number.getText().toString().equals(""))
{
strMobileNumber = ed_Mobile_Number.getText().toString();
new SendPostRequest(getApplicationContext()).execute(strMobileNumber);
}
else
{
Toast.makeText(getApplicationContext(), "Please Enter Mobile Number", Toast.LENGTH_LONG).show();
}
}
});
}
Here is SendPost Request Class which extends Asyntask
public class SendPostRequest extends AsyncTask<String, Void, String> {
public static ProgressDialog pDialog;
private String path = "xxxx";
public String Mobile_Number = "";
private Context mContext;
public SendPostRequest(Context context)
{
this.mContext=context;
pDialog = new ProgressDialog(mContext);
pDialog.setTitle("Loading...");
pDialog.setMessage("Please wait...");
}
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog.show();
}
#Override
protected String doInBackground(String... arg0)
{
try
{
Thread.sleep(40000);
String m_number=arg0[0];
URL url = new URL(path); // here is your URL path
JSONObject postDataParams = new JSONObject();
postDataParams.put("username", "data");
postDataParams.put("password", "data");
postDataParams.put("mobile", m_number);
System.out.println(m_number);
Mobile_Number=m_number;
Log.e("params", postDataParams.toString());
//conversion of 15 min to miliseconds :900000
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
// conn.setReadTimeout(1500/* milliseconds */);
//conn.setConnectTimeout(1500 /* milliseconds */);
conn.setRequestMethod("POST");
conn.setDoInput(true);
conn.setDoOutput(true);
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
writer.write(getPostDataString(postDataParams));
writer.flush();
writer.close();
os.close();
int responseCode = conn.getResponseCode();
if (responseCode == HttpsURLConnection.HTTP_OK) {
BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuffer sb = new StringBuffer("");
String line = "";
while ((line = in.readLine()) != null) {
sb.append(line);
break;
}
in.close();
return sb.toString();
} else {
return new String("false : " + responseCode);
}
} catch (Exception e) {
return new String("Exception: " + e.getMessage());
}
}
#Override
protected void onPostExecute(String result) {
if (pDialog != null && pDialog.isShowing()) {
//Toast.makeText(mContext.getApplicationContext(), result,Toast.LENGTH_LONG).show();
JSONObject jsonObject = null;
try {
jsonObject = new JSONObject(result);
String otp = jsonObject.optString("otp");
Log.d("otp value is", otp);
message(otp);
} catch (JSONException e) {
e.printStackTrace();
}
pDialog.dismiss();
}
}
public String getPostDataString(JSONObject params) throws Exception {
StringBuilder result = new StringBuilder();
boolean first = true;
Iterator<String> itr = params.keys();
while (itr.hasNext()) {
String key = itr.next();
Object value = params.get(key);
if (first)
first = false;
else
result.append("&");
result.append(URLEncoder.encode(key, "UTF-8"));
result.append("=");
result.append(URLEncoder.encode(value.toString(), "UTF-8"));
}
return result.toString();
}
public void message(String otp)
{
Intent myIntent = new Intent(this.mContext,OTP_Code_Activity.class);
myIntent.putExtra("Mobile Number", Mobile_Number);
System.out.println(Mobile_Number);
myIntent.putExtra("OTP Code", otp);
mContext.startActivity(myIntent);
pDialog.dismiss();
}

new SendPostRequest(getApplicationContext()).execute(strMobileNumber);
Change this to activity context.
new SendPostRequest(Mobile_Number_Activity.this).execute(strMobileNumber);

Delete(uninstall) the app from your phone, and run it again..It happens due to some issues with database. Or else I think you haven't mention the activity in the Manifest

Change
new SendPostRequest(getApplicationContext()).execute(strMobileNumber);
To
new SendPostRequest(this).execute(strMobileNumber);
And with Application Context, you can't show Dialog. You need to use Activity instance.
Change
SendPostRequest(Context context)
To
SendPostRequest(Activity context)
It might be helpful. Check log and see have any error in JSON Parse Exception as well.

Android Async Task Freezes UI Completely

I have an Async task that loads information from the server and displays data on the UI. Suddenly the async task downloads the data and formats the JSON data fine but it would freeze the UI completely.
Here is the base download class
public class GetRawData {
private static String LOG_TAG = GetRawData.class.getSimpleName();
private String mRawURL;
private List<NameValuePair> mRawParams = null;
private String mRawData;
private DownloadStatus mDownloadStatus;
public GetRawData(String mRawURL) {
this.mRawURL = mRawURL;
this.mRawParams = null;
this.mDownloadStatus = DownloadStatus.IDLE;
}
public String getRawData() {
return mRawData;
}
public void setRawURL(String mRawURL) {
this.mRawURL = mRawURL;
}
public List<NameValuePair> getRawParams() {
return mRawParams;
}
public void setRawParams(List<NameValuePair> mParams) {
this.mRawParams = mParams;
}
public DownloadStatus getDownloadStatus() {
return mDownloadStatus;
}
public void reset() {
this.mRawURL = null;
this.mRawData = null;
this.mDownloadStatus = DownloadStatus.IDLE;
}
public void execute() {
this.mDownloadStatus = DownloadStatus.PROCESSING;
DownloadRawData mDownloadRawData = new DownloadRawData();
mDownloadRawData.execute(mRawURL);
}
public class DownloadRawData extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... params) {
// Create URL and Reader instances.
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
//If no parameter has been provided, return null.
if (params == null)
return null;
try {
// Get URL entered by the user.
URL mURL = new URL(params[0]);
urlConnection = (HttpURLConnection) mURL.openConnection();
urlConnection.setDoOutput(true);
urlConnection.setRequestMethod("POST");
urlConnection.setUseCaches(false);
urlConnection.setConnectTimeout(10000);
urlConnection.setReadTimeout(10000);
urlConnection.setRequestProperty("Content-Type","application/json");
//urlConnection.setRequestProperty("Host", "android.schoolportal.gr");
urlConnection.connect();
// validate and add parameters if available.
if (mRawParams != null && mRawParams.size()>0){
JSONObject jsonParam = new JSONObject();
for (NameValuePair pair : mRawParams) {
jsonParam.put(pair.getName().toString(), pair.getValue().toString());
}
String jsonparams = jsonParam.toString();
// Send POST output.
DataOutputStream printout;
printout = new DataOutputStream(urlConnection.getOutputStream());
printout.writeBytes(jsonparams);
printout.flush();
printout.close();
}
int HttpResult =urlConnection.getResponseCode();
StringBuffer buffer = new StringBuffer();
if(HttpResult ==HttpURLConnection.HTTP_OK){
InputStream inputStream = urlConnection.getInputStream();
if (inputStream == null) {
return null;
}
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
buffer.append(line + "\n");
}
System.out.println(""+buffer.toString());
}else{
InputStream errorStream = urlConnection.getErrorStream();
if (errorStream == null) {
return null;
}
reader = new BufferedReader(new InputStreamReader(errorStream));
String line;
while ((line = reader.readLine()) != null) {
buffer.append(line + "\n");
}
System.out.println(urlConnection.getResponseMessage());
}
return buffer.toString();
} catch (IOException e) {
Log.d("IOException", e.toString());
return null;
} catch (JSONException j) {
Log.d("JSONException", j.toString());
return null;
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
Log.d("IOException", "unable to close the reader");
}
}
}
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
mRawData = result;
//Log.d("onPostExecute", result);
if (mRawData == null) {
if (mRawURL == null) {
mDownloadStatus = DownloadStatus.NOT_INITIALIZED;
} else {
mDownloadStatus = DownloadStatus.FAILED_OR_EMPTY;
}
} else {
mDownloadStatus = DownloadStatus.PROCESSED;
}
}
private String getQuery(List<NameValuePair> params) throws UnsupportedEncodingException {
StringBuilder result = new StringBuilder();
boolean first = true;
for (NameValuePair 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();
}
}
}
enum DownloadStatus {
IDLE,
PROCESSING,
NOT_INITIALIZED,
FAILED_OR_EMPTY,
PROCESSED
}
Here is the specific data formatting class the extends above class
public class GetJobCardJsonData extends GetRawData {
private static String LOG_TAG = GetAuthenticationJsonData.class.getSimpleName();
private static String JOBCARD_SERVICE_URL = "http://www.appservice.com/appservice/jobcardinfoservice.asmx/GetJobCardInfo";
private List<JobCard> mJobCardList;
private CarcalDownloadListener mListener;
public GetJobCardJsonData(String CurrentDate, int DealershipID) {
super(null);
List<NameValuePair> mParams = new ArrayList<NameValuePair>();
mParams.add(new BasicNameValuePair("JobCardDate", CurrentDate));
mParams.add(new BasicNameValuePair("DealershipID", String.valueOf(DealershipID)));
this.setRawParams(mParams);
}
public List<JobCard> getJobCardList() {
return mJobCardList;
}
public void getjobcards() {
super.setRawURL(JOBCARD_SERVICE_URL);
DownloadJobCardJsonData mDownloadJobCardJsonData = new DownloadJobCardJsonData();
mDownloadJobCardJsonData.execute(JOBCARD_SERVICE_URL);
}
public void setOnCarcalDownloadListener(CarcalDownloadListener onCarcalDownloadListener) {
this.mListener = onCarcalDownloadListener;
}
private void processResult() {
if (getDownloadStatus() != DownloadStatus.PROCESSED) {
Log.e(LOG_TAG, "Error Downloading the raw file.");
return;
}
if (mJobCardList == null){
mJobCardList = new ArrayList<JobCard>();
}
final String JOBCARD_JOBCARDID = "JobCardID";
final String JOBCARD_GETSTOCKNUMBER_WITH_DELIVERYTIME = "StockNumberWithDeliveryTime";
final String JOBCARD_CUSTOMERNAME = "CustomerName";
final String JOBCARD_MODELNUMBER = "ModelNumber";
final String JOBCARD_COLOR = "Color";
final String JOBCARD_SALEEXECUTIVE = "SaleExecutive";
final String JOBCARD_ORDERSTATUS = "OrderStatus";
final String JOBCARD_SHOWROOMSTATUS = "ShowRoomStatus";
try {
JSONArray jsonArray = new JSONArray(getRawData());
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jobcarditem = jsonArray.optJSONObject(i);
Long JOBCARDID = jobcarditem.getLong(JOBCARD_JOBCARDID);
String STOCKWITHDELIVERY = jobcarditem.getString(JOBCARD_GETSTOCKNUMBER_WITH_DELIVERYTIME);
String CUSTOMERNAME = jobcarditem.getString(JOBCARD_CUSTOMERNAME);
String MODELNUMBER = jobcarditem.getString(JOBCARD_MODELNUMBER);
String COLOR = jobcarditem.getString(JOBCARD_COLOR);
String SALEEXECUTIVE = jobcarditem.getString(JOBCARD_SALEEXECUTIVE);
int ORDERSTATUS = jobcarditem.getInt(JOBCARD_ORDERSTATUS);
int SHOWROOMSTATUS = jobcarditem.getInt(JOBCARD_SHOWROOMSTATUS);
JobCard mJobCard = new JobCard(JOBCARDID, STOCKWITHDELIVERY, CUSTOMERNAME, MODELNUMBER, COLOR, SALEEXECUTIVE, ORDERSTATUS, SHOWROOMSTATUS);
mJobCardList.add(mJobCard);
}
} catch (JSONException jsone) {
jsone.printStackTrace();
Log.e(LOG_TAG, "Error processing json data.");
}
}
public class DownloadJobCardJsonData extends DownloadRawData {
#Override
protected String doInBackground(String... params) {
return super.doInBackground(params[0]);
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
processResult();
mListener.OnDownloadCompleted();
}
}
}
Here is the code that is called on the activity
private JobCardRecyclerViewAdapter mJobCardRecyclerViewAdapter;
private GetJobCardJsonData mGetJobCardJsonData;
SessionManager session;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_job_card_calender);
activateToolbarWithHomeEnabled();
String formattedDate="";
if (session.getCurrentDate() == ""){
Calendar c = Calendar.getInstance();
SimpleDateFormat df = new SimpleDateFormat("MM/dd/yyyy");
formattedDate = df.format(c.getTime());
currentDateTextView.setText(formattedDate);
}else {
formattedDate = session.getCurrentDate();
currentDateTextView.setText(formattedDate);
}
// Fetch data for current date.
mGetJobCardJsonData = new GetJobCardJsonData(formattedDate, session.getDealershipID());
mGetJobCardJsonData.getjobcards();
mGetJobCardJsonData.setOnCarcalDownloadListener(new CarcalDownloadListener() {
#Override
public void OnDownloadCompleted() {
List<JobCard> mJobCards = mGetJobCardJsonData.getJobCardList();
mJobCardRecyclerViewAdapter = new JobCardRecyclerViewAdapter(mJobCards, JobCardCalenderActivity.this);
mRecyclerView.setAdapter(mJobCardRecyclerViewAdapter);
}
});
}
Can anyone help on what i am doing wrong that is freezing the UI. It was working fine before and has started to freeze the UI suddenly.

I was able to fix the issue, the problem was not with Async task but with the layout. I accidently wrapped the recycler view with scroll view. which was causing the UI to freeze. Looks weird that a scroll view caused the whole UI thread to freeze. but here is my solution
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<view
android:id="#+id/jobCardRecyclerView"
class="android.support.v7.widget.RecyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/jobCardHeader"
android:scrollbars="vertical"></view>
</ScrollView>
Changed it to
<view
android:id="#+id/jobCardRecyclerView"
class="android.support.v7.widget.RecyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/jobCardHeader"
android:scrollbars="vertical"></view>
hope it will be helpful for others facing same problem.

AsyncTask to fetch global game scores from a server

I am new to android and am completely puzzled by AsyncTasks. I need to create a leaderboard which will pull global leaderboard scores from a server.
I have posted below the two methods that were created in the LeaderboardsFragment which are used to access and display the scores - getGlobalScores and readStream.
I am unsure of how to use these in the AsyncTask - mostly how and what parameters to pass to the AsyncTask - most of the tutorials I have been looking at do not deal with 2D arrays. Any hints would be really appreciated, I am really having trouble understanding the literature surrounding this.
package uk.ni.appidemic.whackamole;
import java.io.BufferedReader;
public class LeaderboardsFragment extends Fragment {
AssetStore AS;
private TextView TopScores;
private String[][] global_scores = new String[10][3];
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_leaderboards, container, false);
//Go and get the asset store from the activity
AS = WhackAMoleActivity.getAssetManager();
TopScores = (TextView) rootView.findViewById(R.id.leaderboards);
// Extract and display the top score text view from the preferences
displayLocalScores();
// this method is used to send a highscore to the server (name and score)
// this method may get pulled out to the gameloop as its the only place it should be used in the final game
// but this can be used for testing purposes atm (Server needs to be on)
// sendScoreGlobal("porter", 1001);
//async Get global scores from the server and display them - new thread
new AsyncOperation().execute();
...................
public void getGlobalScores() {
//gets global score in HTML format to be parsed
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
try {
URL url = new URL("http://62........./high_scores");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
readStream(con.getInputStream());
} catch (Exception e) {
e.printStackTrace();
}
}
/gets the data and stores the global scores in a 2d array
//it then displays to screen
public void readStream(InputStream in) {
BufferedReader reader = null;
try {
StringBuilder htmlIn = new StringBuilder();
StringBuilder globalScoreBuilder = new StringBuilder();
htmlIn.append("");
reader = new BufferedReader(new InputStreamReader(in));
String line = "";
while ((line = reader.readLine()) != null) {
htmlIn.append(line);
}
// String to be scanned to find the pattern.
String html = htmlIn.toString();
String regexPattern = "<td align=\"left\" style=\"padding-left:10px;\">(\\d+?)</td>|<td align=\"right\" style=\"padding-right:10px;\">(\\w+?)</td>";
// Create a Pattern object
Pattern patternObject = Pattern.compile(regexPattern);
// Now create matcher object.
Matcher matcherObject = patternObject.matcher(html);
Log.d(getActivity().getResources().getString(R.string.LOG_TAG), "Trying to find regex matches");
TopScores.append("\n");
int nextFreePointer = 0;
int rowCount = 0;
while (matcherObject.find()) {
if (matcherObject.group(1) != null) {
Log.d(getActivity().getResources().getString(R.string.LOG_TAG), "Regex match : " + matcherObject.group(1));
globalScoreBuilder.append(matcherObject.group(1) + " ");
global_scores[rowCount][nextFreePointer] = matcherObject.group(1);
nextFreePointer++;
}
if (matcherObject.group(2) != null) {
Log.d(getActivity().getResources().getString(R.string.LOG_TAG), "Regex match : " + matcherObject.group(2));
globalScoreBuilder.append(matcherObject.group(2) + " ");
global_scores[rowCount][nextFreePointer] = matcherObject.group(2);
nextFreePointer++;
}
if (nextFreePointer > 2) {
nextFreePointer = 0;
rowCount++;
}
globalScoreBuilder.append("\n");
}
StringBuilder sb = new StringBuilder();
String lineSeparator = System.getProperty("line.separator");
for (String[] row : global_scores) {
sb.append(Arrays.toString(row)).append(lineSeparator);
}
String text = sb.toString();
TopScores.append("Global Top 10 Scores\n");
TopScores.append(text);
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
public class AsyncOperation extends AsyncTask<String, Void, Void>{
protected void onPreExecute(){
}//end of onPreExecute
#Override
protected Void doInBackground(Void... values) {
}//doinBackground
protected void onProgressUpdate(Void... values){
}//onProgressUpdate
protected void onPostExecute(Void... result){
}//end of onPostExecute
}//end of AsyncOperation inner class
}//end of Leaderboards class

You should fetch your game score through a WebService class that extentds AsynTask. Below is my class that I am using in order to fetch remote data safely.
CODE:
public class WebServiceRestTask extends AsyncTask<HttpUriRequest, Void, Object> {
private static final String TAG = "WebServiceRestTask";
private AbstractHttpClient mClient;
private WeakReference<WebServiceRestCallback> mCallback;
private int ws_task;
public WebServiceRestTask(int ws_task) {
this(new DefaultHttpClient(), ws_task);
}
public WebServiceRestTask(AbstractHttpClient client, int task_number) {
mClient = client;
this.ws_task = task_number;
}
public interface WebServiceRestCallback {
public void onRequestSuccess(String response);
public void onRequestError(Exception error);
}
public void setResponseCallback(WebServiceRestCallback callback) {
mCallback = new WeakReference<WebServiceRestCallback>(callback);
}
#Override
protected Object doInBackground(HttpUriRequest... params) {
try {
HttpUriRequest request = params[0];
HttpResponse serverResponse = mClient.execute(request);
BasicResponseHandler handler = new BasicResponseHandler();
String response = handler.handleResponse(serverResponse);
return response + ws_task;
} catch (Exception e) {
Log.w(TAG, e);
return e;
}
}
#Override
protected void onPostExecute(Object result) {
if (mCallback != null && mCallback.get() != null) {
if (result instanceof String) {
mCallback.get().onRequestSuccess((String) result);
} else if (result instanceof Exception) {
mCallback.get().onRequestError((Exception) result);
} else {
mCallback.get().onRequestError(
new IOException("Unknown Error Contacting Host"));
}
}
}
}

Not at my workstation but think something like this should work.
public class AsyncOperation extends AsyncTask<String, Void, Void>{
private String[][] global_scores = new String[10][3];
protected void onPreExecute(){
// optionally show loading indicator
TopScores.append("\n");
}//end of onPreExecute
#Override
protected Void doInBackground(Void... values) {
try {
URL url = new URL("http://62........./high_scores");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
readStream(con.getInputStream());
} catch (Exception e) {
e.printStackTrace();
}
}//doinBackground
protected void onProgressUpdate(Void... values){
}//onProgressUpdate
protected void onPostExecute(Void... result){
// optionally hide loading indicator
StringBuilder sb = new StringBuilder();
String lineSeparator = System.getProperty("line.separator");
for (String[] row : global_scores) {
sb.append(Arrays.toString(row)).append(lineSeparator);
}
String text = sb.toString();
TopScores.append("Global Top 10 Scores\n");
TopScores.append(text);
}//end of onPostExecute
private void readStream(InputStream in) {
BufferedReader reader = null;
try {
StringBuilder htmlIn = new StringBuilder();
StringBuilder globalScoreBuilder = new StringBuilder();
htmlIn.append("");
reader = new BufferedReader(new InputStreamReader(in));
String line = "";
while ((line = reader.readLine()) != null) {
htmlIn.append(line);
}
// String to be scanned to find the pattern.
String html = htmlIn.toString();
String regexPattern = "<td align=\"left\" style=\"padding-left:10px;\">(\\d+?)</td>|<td align=\"right\" style=\"padding-right:10px;\">(\\w+?)</td>";
// Create a Pattern object
Pattern patternObject = Pattern.compile(regexPattern);
// Now create matcher object.
Matcher matcherObject = patternObject.matcher(html);
Log.d(getActivity().getResources().getString(R.string.LOG_TAG), "Trying to find regex matches");
int nextFreePointer = 0;
int rowCount = 0;
while (matcherObject.find()) {
if (matcherObject.group(1) != null) {
Log.d(getActivity().getResources().getString(R.string.LOG_TAG), "Regex match : " + matcherObject.group(1));
globalScoreBuilder.append(matcherObject.group(1) + " ");
global_scores[rowCount][nextFreePointer] = matcherObject.group(1);
nextFreePointer++;
}
if (matcherObject.group(2) != null) {
Log.d(getActivity().getResources().getString(R.string.LOG_TAG), "Regex match : " + matcherObject.group(2));
globalScoreBuilder.append(matcherObject.group(2) + " ");
global_scores[rowCount][nextFreePointer] = matcherObject.group(2);
nextFreePointer++;
}
if (nextFreePointer > 2) {
nextFreePointer = 0;
rowCount++;
}
globalScoreBuilder.append("\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}//end of AsyncOperation inner class