How do I get the data from my AsyncTask? My MainActivity is calling the DataCall.getJSON function that triggers the AsyncTask but I am not sure how to get the data back to the original Activity.
MainActivity with call to DataCall that should return a string and save it in state_data
String state_data = DataCall.getJSON(spinnerURL,spinnerContentType);
DataCall:
public class DataCall extends Activity {
private static final String TAG = "MyApp";
private class DownloadWebPageTask extends AsyncTask<String, Void, String> {
protected String doInBackground(String... urls) {
String response = "";
for (String url : urls) {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
try {
HttpResponse execute = client.execute(httpGet);
InputStream content = execute.getEntity().getContent();
BufferedReader buffer = new BufferedReader(
new InputStreamReader(content));
String s = "";
while ((s = buffer.readLine()) != null) {
response += s;
}
} catch (Exception e) {
e.printStackTrace();
}
}
return response;
}
protected void onPostExecute(String result) {
//THIS IS WHERE I NEED TO RETURN MY DATA TO THE MAIN ACTIVITY. (I am guessing)
}
}
public void getJSON(String myUrlString, String contentType) {
DownloadWebPageTask task = new DownloadWebPageTask();
task.execute(new String[] { "http://www.mywebsite.com/" + myUrlString });
}
}
modify your AsyncTask as below:
public class GetData extends AsyncTask<String, Void, String>
{
DataDownloadListener dataDownloadListener;
public GetData()
{
//Constructor may be parametric
}
public void setDataDownloadListener(DataDownloadListener dataDownloadListener) {
this.dataDownloadListener = dataDownloadListener;
}
#Override
protected Object doInBackground(Object... param)
{
// do your task...
return null;
}
#Override
protected void onPostExecute(Object results)
{
if(results != null)
{
dataDownloadListener.dataDownloadedSuccessfully(results);
}
else
dataDownloadListener.dataDownloadFailed();
}
public static interface DataDownloadListener {
void dataDownloadedSuccessfully(Object data);
void dataDownloadFailed();
}
}
and use it in your Activity
GetData getdata = new GetData();
getdata.setDataDownloadListener(new DataDownloadListener()
{
#SuppressWarnings("unchecked")
#Override
public void dataDownloadedSuccessfully(Object data) {
// handler result
}
#Override
public void dataDownloadFailed() {
// handler failure (e.g network not available etc.)
}
});
getdata.execute("");
NOTE: For the people who are reading this.
Please consider this post for the best and perhaps right implementation.
The key for me was to create a class called URLWithParams or something because AsyncTask will allow only 1 type to be sent IN, and I needed both the URL and the params for the HTTP request.
public class URLWithParams {
public String url;
public List<NameValuePair> nameValuePairs;
public URLWithParams()
{
nameValuePairs = new ArrayList<NameValuePair>();
}
}
and then I send it to a JSONClient:
public class JSONClient extends AsyncTask<URLWithParams, Void, String> {
private final static String TAG = "JSONClient";
ProgressDialog progressDialog ;
GetJSONListener getJSONListener;
public JSONClient(GetJSONListener listener){
this.getJSONListener = listener;
}
#Override
protected String doInBackground(URLWithParams... urls) {
return connect(urls[0].url, urls[0].nameValuePairs);
}
public static String connect(String url, List<NameValuePair> pairs)
{
HttpClient httpclient = new DefaultHttpClient();
if(url == null)
{
Log.d(TAG, "want to connect, but url is null");
}
else
{
Log.d(TAG, "starting connect with url " + url);
}
if(pairs == null)
{
Log.d(TAG, "want to connect, though pairs is null");
}
else
{
Log.d(TAG, "starting connect with this many pairs: " + pairs.size());
for(NameValuePair dog : pairs)
{
Log.d(TAG, "example: " + dog.toString());
}
}
// Execute the request
HttpResponse response;
try {
// Prepare a request object
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(pairs));
response = httpclient.execute(httpPost);
// Examine the response status
Log.i(TAG,response.getStatusLine().toString());
BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8"));
String json = reader.readLine();
return json;
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String json ) {
getJSONListener.onRemoteCallComplete(json);
}
public interface GetJSONListener {
public void onRemoteCallComplete(String jsonFromNet);
}
}
Then call it from my main class like this
public class BookCatalog implements GetJSONListener {
private final String TAG = this.getClass().getSimpleName();
private String catalog_url = "URL";
private void getCatalogFromServer() {
URLWithParams mURLWithParams = new URLWithParams();
mURLWithParams.url = catalog_url;
try {
JSONClient asyncPoster = new JSONClient(this);
asyncPoster.execute(mURLWithParams);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
public void onRemoteCallComplete(String jsonBookCatalogList) {
Log.d(TAG, "received json catalog:");
Log.d(TAG, jsonBookCatalogList);
JSONObject bookCatalogResult;
try {
bookCatalogResult = (JSONObject) new JSONTokener(jsonBookCatalogList).nextValue();
JSONArray books = bookCatalogResult.getJSONArray("books");
if(books != null) {
ArrayList<String> newBookOrdering = new ArrayList<String>();
int num_books = books.length();
BookCatalogEntry temp;
DebugLog.d(TAG, "apparently we found " + Integer.toString(num_books) + " books.");
for(int book_id = 0; book_id < num_books; book_id++) {
JSONObject book = books.getJSONObject(book_id);
String title = book.getString("title");
int version = book.getInt("price");
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
Although i disagree creating a new activity for that simple task there is
startActivityForResult()
to get data from another activity.
Check this. You can store your data to the Intent's extras. But still if you have a large amount of data you better off write it to a file get the result from the other activity that is done downloading and then read the file.
Serialize it and then read it. The only way I'm aware of.
Some options:
a) Make your bean implement Serializable interface, you can then pass your bean through Intent.
b) Implement Application interface (you need to make an entry in manifest), Have setter\getter method in your Application class. You can set your bean in Application from AsyncTask and later retrieve from Activity.
Sorry for answering so late, i think by this time you might have solved this problem. when i was searching for something else, i came across your question. I'm pasting a link here which might of some help for others.
Related
Below is my code, lat_val and long_val is not getting updated with received value from JSON response in btnShowLoc(), it is referencing to the default value which is 0,0. I want the global variable to keep updating when ever referenced and updated with JSON response.
public class MainActivity extends Activity {
public static String lat_val = "0";
public static String long_val = "0";
public String readJSONFeed(String urlStr) {
StringBuilder stringBuilder = new StringBuilder();
try {
URL url = new URL(urlStr);
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestProperty("SisApiKey", "4572c3c9-73cb-4958-9649-26c1e8df27e8");
urlConnection.setRequestProperty("SisSmartKey", "d1aebd25-774c-4e8a-b3a5-ee5a603cc603");
InputStream ins = urlConnection.getInputStream();
urlConnection.connect();
int statusCode = urlConnection.getResponseCode();
if (statusCode == 200) {
BufferedReader br = new BufferedReader(new InputStreamReader(ins));
String line;
while ((line = br.readLine()) != null) {
stringBuilder.append(line);
}
ins.close();
} else {
Log.d("JSON", "Failed to download file");
}
} catch (java.net.MalformedURLException e) {
e.printStackTrace();
} catch (java.io.IOException e) {
e.printStackTrace();
} catch (Exception e) {
Log.d("readJSONFeed", e.getLocalizedMessage());
}
return stringBuilder.toString();
}
public class ReadJSONFeedTask extends AsyncTask
<String, Void, String> {
protected String doInBackground(String... url) {
return readJSONFeed(url[0]);
}
protected void onPostExecute(String result) {
try {
JSONObject jsonObject = new JSONObject(result);
//JSONObject flags = new JSONObject(jsonObject.getString("flag"));
JSONObject locationItems = new JSONObject(jsonObject.getString("response"));
//Log.v("Location Details :", locationItems.toString());
String []dev_loc = locationItems.toString().split("[\\s*,\\s*]");
MainActivity.lat_val = dev_loc[0]; //"12.9934136";
MainActivity.long_val = dev_loc[1]; //"80.2464206";
} catch (Exception e) {
Log.d("ReadJSONFeedTask", e.getLocalizedMessage());
}
}
}
public void btnGetDevLoc(View view) {
String sp_val = String.valueOf(spinner1.getSelectedItem());
new ReadJSONFeedTask().execute(
"http://15.153.133.160:21743/sis/sie/api/v1/applications/bb9f05fb-a796-4b75-9db7-c999360ad185/virtualobjects/d77d3905-aa77-41b9-9034-b0052bfde405?secondString=HWE_ASSET_ANDROID"); // + sp_val);
}
public void btnShowLoc(View view) {
//lat_val = "12.9934136";
//long_val = "80.2464206";
Intent in = new Intent(MainActivity.this, MapActivity.class);
Bundle bundle = new Bundle();
bundle.putString("latitude", MainActivity.lat_val);
bundle.putString("longitude", MainActivity.long_val);
in.putExtras(bundle);
startActivity(in);
}
With the few information you have shared, and given that
btnGetDevLoc() and btnShowLoc()are the functions executed when clicked on buttons in the application defined in activity_main.xml
and that
First btnGetDevLoc() is called then btnShowLoc()
the first thing that pops out in my mind is that the AsyncTask has not yet finished updating the String values, when you call btnShowLoc().
So, if btnGetDevLoc() and btnShowLoc() are called sequentially, like
... onClick() {
btnGetDevLoc();
btnShowLoc();
}
then it's most likely due to what I said above. Remember that AsyncTask runs asynchronously (as the name says...).
You can test this really small program.
public static double var1 = 0.0;
public static void main(String[] args) {
new Thread(() -> {
var1 = 1.0;
}).start();
System.out.println(var1);
}
It will almost always print 0.0, because the value of var1 is not updated yet when the main thread prints it.
What you should do is place your btnShowLoc() call at the end of onPostExecute(String). This guarantees that your method is called only after you have updated the new values.
I can't Understand, when the btnGetDevLoc() and btnShowLoc() called? Can you post your whole MainActivity?
Edit :
It's seems like you call btnShowLoc() before your AsyncTask finish its proccess.
You can change your code this way to make sure your btnShowLoc() called after your AsyncTask :
public class ReadJSONFeedTask extends AsyncTask
<String, Void, String> {
protected String doInBackground(String... url) {
return readJSONFeed(url[0]);
}
protected void onPostExecute(String result) {
try {
JSONObject jsonObject = new JSONObject(result);
//JSONObject flags = new JSONObject(jsonObject.getString("flag"));
JSONObject locationItems = new JSONObject(jsonObject.getString("response"));
//Log.v("Location Details :", locationItems.toString());
String []dev_loc = locationItems.toString().split("[\\s*,\\s*]");
MainActivity.lat_val = dev_loc[0]; //"12.9934136";
MainActivity.long_val = dev_loc[1]; //"80.2464206";
btnShowLoc(dev_loc[0], dev_loc[1]);
} catch (Exception e) {
Log.d("ReadJSONFeedTask", e.getLocalizedMessage());
}
}
}
public void btnShowLoc(String latitude, String longitude) {
//lat_val = "12.9934136";
//long_val = "80.2464206";
Intent in = new Intent(MainActivity.this, MapActivity.class);
Bundle bundle = new Bundle();
bundle.putString("latitude", latitude);
bundle.putString("longitude", longitude);
in.putExtras(bundle);
startActivity(in);
}
I have this MainActivity which does two HTTP calls and return the JSON object back to the MainActivity class. I have seperately implemented the AsyncTask class and used the AsyncResponse interface to get the JSON object to the MainActivity by using the processFinish function call.
At first I came up with one HTTP call which worked perfectly.
Secondly I wanted to do another HTTP call in the same activity class. So I edit the code to cater the second HTTP call.
When I run the application, only the first HTTP call is working. When I call the second HTTP call it throws an exception saying reference to a null object
Then I checked by logging the onPostExecute method which calls the processFinish function. There I could see the JSON Object. So, that means the second JSON object doesn't get to the processFinish
How do I manage the second HTTP call? Please help me! I am new to Android.
Following is my AsyncTask class...
public class ServiceHandler extends AsyncTask<String, Void, JSONObject> {
String startStationID;
String endStationID;
String searchDate;
String startTime;
String endTime;
public ServiceHandler(String startStationID, String endStationID, String searchDate, String startTime, String endTime) {
this.startStationID = startStationID;
this.endStationID = endStationID;
this.searchDate = searchDate;
this.startTime = startTime;
this.endTime = endTime;
}
public interface AsyncResponse {
void processFinish(JSONObject output);
}
public AsyncResponse delegate=null;
public ServiceHandler(AsyncResponse delegate) {
this.delegate = delegate;
}
#Override
protected JSONObject doInBackground(String... params) {
String method = params[0];
JSONObject JSON_Object = null;
if (method.equals("getStations")) {
JSON_Object = Constants.apiCall("http://api.lankagate.gov.lk:8280/railway/1.0/station/getAll?lang=en");
} else if (method.equals("searchTrains")) {
JSON_Object = Constants.apiCall("http://api.lankagate.gov.lk:8280/railway/1.0/train/searchTrain?" +
"startStationID="+this.startStationID+"&" +
"endStationID="+this.endStationID+"&" +
"searchDate="+this.searchDate+"&" +
"startTime="+this.startTime+"&" +
"endTime="+this.endTime+"&" +
"lang=en");
}
return JSON_Object;
}
#Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
#Override
protected void onPostExecute(JSONObject obj) {
try{
Log.d("onPostExecute",obj.toString());
delegate.processFinish(obj);
}catch (Exception e){
Log.e("onPostExecute",e.getMessage());
}
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
}
Following is my processFinish function...
#Override
public void processFinish(JSONObject output) {
Log.d("processFinish",output.toString());
if(!isSearchClicked) {
//Get all the stations...
if (output != null) {
Toast.makeText(MainActivity.this, "Successfully Connected!", Toast.LENGTH_SHORT).show();
try {
JSONObject obj = output.getJSONObject("RESULTS");
output = null;
JSONArray dataArray = obj.getJSONArray("stationList");
for (int i = 0; i < dataArray.length(); i++) {
JSONObject object1 = dataArray.getJSONObject(i);
String stationID = object1.getString("stationID");
String stationName = object1.getString("stationName");
stationNames.add(stationName);
stationIDs.add(stationID);
// stations.put(stationID,stationName);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Toast.makeText(MainActivity.this, " Connection Failed!", Toast.LENGTH_SHORT).show();
}
}else {
//search click action...
if (output != null) {
Toast.makeText(MainActivity.this, "Successfully Searched!", Toast.LENGTH_SHORT).show();
try {
JSONObject obj = output.getJSONObject("RESULTS");
JSONArray directTrains = obj.getJSONArray("directTrains");
// Log.d("array size",String.valueOf(directTrains.length()));
// for (int i = 0; i < directTrains.length(); i++) {
// JSONObject object1 = directTrains.getJSONObject(i);
//
// String stationID = object1.getString("stationID");
// String stationName = object1.getString("stationName");
// Log.d("JArr", stationID + " : " + stationName);
//
// stationNames.add(stationName);
// stationIDs.add(stationID);
//// stations.put(stationID,stationName);
// }
// Log.d("stationNames", stationNames.toString());
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Toast.makeText(MainActivity.this, " Connection Failed!", Toast.LENGTH_SHORT).show();
Log.d("output",output.toString());
}
}
}
Following is my first HTTP call...
ServiceHandler sh = new ServiceHandler(this);
String method = "getStations";
sh.execute(method);
Following is my second HTTP call...
String method = "searchTrains"
ServiceHandler sh = new ServiceHandler(startStationID,endStationID,searchDate,startTime,endTime);
sh.execute(method);
Although I don't understand exactly what your problem is. There are few things I suggest you to do.
Here I go.
Don't use AsyncTask to make your http calls , use an intent services instead.
Use a OkHTTP library for your networking source
On your intent service send local broadcast with LocalBroadcastManager to broadcast your results from the http call.
Register broadcastsReceivers within your activities or fragments that will listen for those broadcasts that comes from the intent service
Why not to use AsyncTask: Because of configuration change - if you rotate your device you will lose that network calls-
Read about intent services here
I was using this in another place as async but I wanted to refactor to make it reusable, how can I reorganize the code in order to work as a consumable class?. It doesn't work if it's not async and the ip of the backend is well defined so it's not that. Any ideas?
public class HTTPRequestManager {
public static JSONArray fetchData(){
return null;
}
public static String postData(Context context, String url, String JSONData) {
return null;
}
/* #Override
protected Integer doInBackground(String... strings) {
try {
//1.create client Object
OkHttpClient client = new OkHttpClient();
//2.Define request being sent to server
RequestBody postData = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), JSONData);
Request request = new Request.Builder()
.url(context.getResources().getString(R.string.backend_base_url) + url)
.post(postData)
.build();
//3.Transport the request and wait for response to process next
Response response = client.newCall(request).execute();
String resultData = response.body().string();
if (resultData.equals("OK")) {
} else {
//post failed
return "FAILED";
}
return resultData;
} catch (Exception e) {
Log.d("API_CONNECTION_ERROR", "Couldn't connect to the API");
return "API_CONNECTION_ERROR";
}
}*/
}
I used to have this annonymous class embeeded in another class and it works(it's a get request) but the problem is that it's not reusable in that way:
public class AsyncHttpTask extends AsyncTask<String, Void, Integer> {
URL url = null;
#Override
protected void onPreExecute() {
getActivity().setProgressBarIndeterminateVisibility(true);
}
#Override
protected Integer doInBackground(String... params) {
Integer result = 0;
HttpURLConnection urlConnection;
try {
url = new URL (getResources().getString(R.string.backend_base_url) +
"api/flrcks/user/id/0/latitude/3000/longitude/300/within/9999999999999999999999999");
urlConnection = (HttpURLConnection) url.openConnection();
int statusCode = urlConnection.getResponseCode();
// 200 represents HTTP OK
if (statusCode == 200) {
BufferedReader r = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
StringBuilder response = new StringBuilder();
String line;
while ((line = r.readLine()) != null) {
response.append(line);
}
parseResult(response.toString());
result = 1; // Successful
} else {
result = 0; //"Failed to fetch data!";
}
} catch (Exception e) {
Log.d(TAG, e.getLocalizedMessage());
}
return result; //"Failed to fetch data!";
}
#Override
protected void onPostExecute(Integer result) {
// Download complete. Let us update UI
progressBar.setVisibility(View.GONE);
if (result == 1) {
adapter = new MyRecyclerAdapter_Nearby(getActivity(), feedsList);
mRecyclerView.setAdapter(adapter);
checkAdapterIsEmpty();
} else {
Toast.makeText(getActivity(), "Failed to fetch data!", Toast.LENGTH_SHORT).show();
t.setVisibility(View.VISIBLE);
}
}
private void parseResult(String result) {
try {
JSONObject response = new JSONObject(result);
JSONArray posts = response.getJSONArray("rows");
feedsList = new ArrayList<>();
JSONArray members;
for (int i = 0; i < posts.length(); i++) {
memberList = new ArrayList<>();
final JSONObject post = posts.optJSONObject(i);
members=post.getJSONArray("members");
final FeedItem item = new FeedItem();
//for (int i = 0; i < posts.length(); i++) {
//JSONObject post = posts.optJSONObject(i);
//FeedItem item = new FeedItem();
item.setId(post.optString("id"));
item.setTitle(post.optString("name"));
item.setDescription(post.optString("description"));
item.setPrivacy(post.optString("privacy_mode_description"));
item.setInitial_date(post.optString("initial_date"));
item.setThumbnail(post.optString("thumbnail"));
item.setColor_hex(post.optString("color_hex"));
item.setTag(post.optString("tag"));
item.setDistance(post.optInt("st_distance"));
//item.setThumbnail(post.optString("thumbnail"));
for(int k=0; k <members.length();k++)
{
MemberItem memberItem = new MemberItem();
JSONObject member = members.optJSONObject(k);
memberItem.setName(member.optString("name"));
memberItem.setUsername(member.optString("username"));
memberItem.setProfile_pic(member.optString("profile_pic"));
memberItem.setIs_moderator(member.optBoolean("is_moderator"));
memberItem.setFacebookId(member.optString("facebook_id"));
memberList.add(memberItem);
}
item.setMemberList(memberList);
feedsList.add(item);
}
}
catch (JSONException e) {
e.printStackTrace();
}
}
}
What changes do I need to make to put it in an isolated file to be consumed by the whole app like for example in a file called OkHTTPRequests.class???
Create an interface
public interface OnWebResponseListener {
void onWebResponse(CommonUtilities.services service, String result);
}
create a public enum for identifying service. in my case i created a CommonUtilities java where i declared
public enum services {
LOGIN
}
Your Common File
public class CallAddr extends AsyncTask<String, Void, String> {
CommonUtilities.services service;
OnWebResponseListener onWebResponseListener;
String url;
FormBody.Builder body;
Request request;
OkHttpClient client;
final static String TAG = "CallAddr";
public CallAddr(Map<String, String> data, CommonUtilities.services service, OnWebResponseListener onWebResponseListener, String url) {
this.service = service;
this.onWebResponseListener = onWebResponseListener;
this.url = url;
body = new FormBody.Builder();
for (String key : data.keySet()) {
body.add(key, data.get(key));
}
client = new OkHttpClient();
}
#Override
protected String doInBackground(String... strings) {
String result = "";
request = new Request.Builder().url(url).post(body.build()).build();
try {
Response response = client.newCall(request).execute();
result = response.body().string();
} catch (Exception e) {
Log.e(TAG,Log.getStackTraceString(e));
}
return result;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
if (onWebResponseListener != null) {
onWebResponseListener.onWebResponse(service, s);
}
}
}
I use below code to produce JSON string and parse it in php. I create an instace of this class and call setData method
//#PART1
String s = "{\"Category\":";
List<CategoryModel> pmo = new ArrayList<CategoryModel>();
pmo = CategoryModule.getAllRecords(c);
s += new JSONSerializer().serialize(pmo);
s += ",\"Data\":";
//#PART2
List<DataModel> amo = new ArrayList<DataModel>();
amo = DataModule.getAllRecords(c);
s += new JSONSerializer().serialize(amo);
s += "}";
I decode the result by below code
$categories = json_decode($data)->{'Category'};
$datas = json_decode($data)->{'Data'};
$username = "kkk";
foreach($categories as $category){
$id = $category->{'id'};
$name = $category->{'name'};
$sql = "INSERT INTO category (id,name,username) VALUES ('$id','$name','$username')";
$link->query($sql);
}
foreach($datas as $data){
$id = $data->{'id'};
$text = $data->{'text'};
$date = $data->{'date'};
$sql = "INSERT INTO data (id,text,date,username) VALUES ('$id','$name','$date','$username')";
$link->query($sql);
}
When I just use #PART1 to produce json string in the php code the decoding occurs in success. But when I add #PART2 to JSON string no one of them decodes successfully. I guess the problem can be from java code.
Please guide me
JSON result is http://aiga.ir/webservice/datastore/a.txt
I use this code for sending data
package ir.aiga.apps.network;
public class WebServiceComm extends AsyncTask<String, Void, Void> {
// Required initialization
private String Content;
private String Error = null;
private ProgressDialog Dialog;
private String data ="";
private boolean visible=true;
private InterFace doInPreExecute=new InterFace() {
#Override
public void doSomething() {
// TODO Auto-generated method stub
}
#Override
public void getResult(String output) {
// TODO Auto-generated method stub
}
#Override
public void getJSONArray(JSONArray array) {
// TODO Auto-generated method stub
}
};
private InterFace doInPostExecute=new InterFace() {
#Override
public void doSomething() {
// TODO Auto-generated method stub
}
#Override
public void getResult(String output) {
// TODO Auto-generated method stub
}
#Override
public void getJSONArray(JSONArray array) {
// TODO Auto-generated method stub
}
};
public WebServiceComm(Context context,String title,String text){
try {
data +="&" + URLEncoder.encode("data", "UTF-8") + "=";
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Dialog=new ProgressDialog(context,ProgressDialog.STYLE_SPINNER);
Dialog.setTitle(title);
Dialog.setMessage(text);
}
public WebServiceComm(){
try {
data +="&" + URLEncoder.encode("data", "UTF-8") + "=";
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void setData(String data){
this.data+=data;
}
protected void onPreExecute() {
// NOTE: You can call UI Element here.
if(visible)
Dialog.show();
}
// Call after onPreExecute method
protected Void doInBackground(String... urls) {
/************ Make Post Call To Web Server ***********/
BufferedReader reader=null;
// Send data
try
{
// Defined URL where to send data
URL url = new URL(urls[0]);
// Send POST data request
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
wr.write( data );
wr.flush();
// Get the server response
reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuilder sb = new StringBuilder();
String line = null;
// Read Server Response
while((line = reader.readLine()) != null)
{
// Append server response in string
sb.append(line + "");
}
// Append Server Response To Content String
Content = sb.toString();
}
catch(Exception ex)
{
Error = ex.getMessage();
ex.printStackTrace();
}
finally
{
try
{
reader.close();
}
catch(Exception ex) {
ex.printStackTrace();
}
}
/*****************************************************/
return null;
}
protected void onPostExecute(Void unused) {
// NOTE: You can call UI Element here.
if (Error != null) {
} else {
// Show Response Json On Screen (activity)
/****************** Start Parse Response JSON Data *************/
JSONObject jsonResponse;
try {
/****** Creates a new JSONObject with name/value mappings from the JSON string. ********/
jsonResponse = new JSONObject(Content);
/***** Returns the value mapped by name if it exists and is a JSONArray. ***/
/******* Returns null otherwise. *******/
JSONArray jsonMainNode = jsonResponse.optJSONArray("Android");
doInPostExecute.getJSONArray(jsonMainNode);
doInPostExecute.doSomething();
if(visible)
Dialog.dismiss();
} catch (Exception e) {
e.printStackTrace();
}
}
}
/**
* #return the doInPreExecute
*/
public InterFace getDoInPreExecute() {
return doInPreExecute;
}
/**
* #param doInPreExecute the doInPreExecute to set
*/
public void setDoInPreExecute(InterFace doInPreExecute) {
this.doInPreExecute = doInPreExecute;
}
/**
* #return the doInPostExecute
*/
public InterFace getDoInPostExecute() {
return doInPostExecute;
}
/**
* #param doInPostExecute the doInPostExecute to set
*/
public void setDoInPostExecute(InterFace doInPostExecute) {
this.doInPostExecute = doInPostExecute;
}
/**
* #return the visible
*/
public boolean isVisible() {
return visible;
}
/**
* #param visible the visible to set
*/
public void setVisible(boolean visible) {
this.visible = visible;
}
}
please try to use this code for sending and receiving JSON with utf-8 encoding:
try {
URL url = new URL("your url");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter writer = new OutputStreamWriter(
conn.getOutputStream(), "UTF-8");
String request = "your json";
writer.write(request);
writer.flush();
System.out.println("Code:" + conn.getResponseCode());
System.out.println("mess:" + conn.getResponseMessage());
String response = "";
BufferedReader reader = new BufferedReader(new InputStreamReader(
conn.getInputStream(), "UTF-8"));
String line;
while ((line = reader.readLine()) != null) {
response += line;
}
System.out.println(new String(response.getBytes(), "UTF8"));
writer.close();
reader.close();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
It's very bad to manually build JSON manually.
Using a JSON Mapper library
public class MyCustomModel {
public List<CategoryModel> Category;
public List<DataModel> Data;
public class CategoryModel{
//code here
}
public class DataModel{
//code here
}
}
Then use it GSON to serialize that object into JSON
MyCustomModel customModel = new MyCustomModel();
//populate object
//......
Gson gson = new Gson();
String json = gson.toJson(customModel);
Using standard library
JSONArray categoryArr = new JSONArray();
List<CategoryModel> categories = CategoryModule.getAllRecords(c);
for (CategoryModel category : categories) {
JSONObject categoryObj = new JSONObject();
categoryObj.put("class", category.getClass());
categoryObj.put("id", category.getId());
categoryObj.put("name", category.getName());
categoryArr.put(categoryObj);
}
Then do the same with the other list then combine both array
JSONObject jObject = new JSONObject();
jObject.put("Category", categoryArr);
jObject.put("Data", dataArr);
Now in my app i try to do http parsing from url, but i didn't carry about threads, before this time...
I have such class and method:
public class TwitterOAuthHelper {
public String httpQueryToApi(String url) {
HttpGet get = new HttpGet(url);
HttpParams params = new BasicHttpParams();
HttpProtocolParams.setUseExpectContinue(params, false);
get.setParams(params);
String response = null;
try {
SharedPreferences settings = context.getSharedPreferences("my_app", 0);
String userKey = settings.getString("user_key", "");
String userSecret = settings.getString("user_secret", "");
consumer.setTokenWithSecret(userKey, userSecret);
consumer.sign(get);
DefaultHttpClient client = new DefaultHttpClient();
response = client.execute(get, new BasicResponseHandler());
} catch (Exception e) {
displayToast("Failed to get data.");
}
return response;
}
}
and now i try to move this logic into asyncTask:
String result;
public String httpQueryToApi(String url) {
new AsyncTask<String,Void,String>(){
#Override
protected String doInBackground(String... params) {
HttpGet get = new HttpGet(String.valueOf(params));
HttpParams param = new BasicHttpParams();
HttpProtocolParams.setUseExpectContinue(param, false);
get.setParams(param);
String response = null;
try {
SharedPreferences settings = context.getSharedPreferences("my_app", 0);
String userKey = settings.getString("user_key", "");
String userSecret = settings.getString("user_secret", "");
consumer.setTokenWithSecret(userKey, userSecret);
consumer.sign(get);
DefaultHttpClient client = new DefaultHttpClient();
response = client.execute(get, new BasicResponseHandler());
} catch (Exception e) {
displayToast("Failed to get data.");
}
result = response;
return response;
}
}.execute(url);
return result;
}
but how can i return my response result value to method?
what is the best practice of doing that?
dd below method to asynctask body (below doInBackground method):
#Override
protected void onPostExecute(String result) {
// result is your returned value from doInBackground
// now we are in main ui thread
}
If you want a callback to antoher method it should be interface
public interface ResultInterface {
public void resultFromHttp(String result);
}
then your method
public String httpQueryToApi(String url, final ResultInterface ri){
//as bove
#Override
protected void onPostExecute(String result) {
if(ri!=null)
ri.resultFromHttp(result);
}
}
implement ResultInterface in your Activity/Fragment/whatever is calling httpQueryToApi, pass this as second param (ri interface)
You can't since the Task will be executed in another thread.
However you could use a callback to get the result.
Take a look at: https://stackoverflow.com/a/19520293/4299154.
Initially your function returned a string which you then further processed. Fine.
But you can not use threading like that. You can not return result from the function, because it has not been set yet (well you can but it will return null). The correct way of doing this is
public void httpQueryToApi(String url) {
new AsyncTask<String,Void,String>(){
#Override
protected String doInBackground(String... params) {
HttpGet get = new HttpGet(String.valueOf(params));
HttpParams param = new BasicHttpParams();
HttpProtocolParams.setUseExpectContinue(param, false);
get.setParams(param);
String response = null;
try {
SharedPreferences settings = context.getSharedPreferences("my_app", 0);
String userKey = settings.getString("user_key", "");
String userSecret = settings.getString("user_secret", "");
consumer.setTokenWithSecret(userKey, userSecret);
consumer.sign(get);
DefaultHttpClient client = new DefaultHttpClient();
response = client.execute(get, new BasicResponseHandler());
} catch (Exception e) {
displayToast("Failed to get data.");
}
return response;
}
#Override
protected void onPostExecute(String s) {
//here s is the response string, do what ever you want
super.onPostExecute(s);
}
}.execute(url);
}
You will have to shift your further processing logic to onPostExecute, no other way :)
If you want do dig a little deeper look into Future<>
1) Create separate class for you Async (not anonymous).
2) Create interface class.
public interface AsyncResponse {
void onProcessFinish(String output);
}
3) In your Async class, you need to declare it (interface : AsyncResponse):
public class MyAsyncTask extends AsyncTask<String,Void,String>(){
public AsyncResponse listener = null;
public MyAsyncTask(AsyncResponse l) {
this.listener = l;
}
{...}
#Override
protected String doInBackground(String... params) {
HttpGet get = new HttpGet(String.valueOf(params));
HttpParams param = new BasicHttpParams();
HttpProtocolParams.setUseExpectContinue(param, false);
get.setParams(param);
String response = null;
try {
SharedPreferences settings = context.getSharedPreferences("my_app", 0);
String userKey = settings.getString("user_key", "");
String userSecret = settings.getString("user_secret", "");
consumer.setTokenWithSecret(userKey, userSecret);
consumer.sign(get);
DefaultHttpClient client = new DefaultHttpClient();
response = client.execute(get, new BasicResponseHandler());
} catch (Exception e) {
displayToast("Failed to get data.");
}
result = response;
return response;
}
#Override
protected void onPostExecute(String result) {
listener.onProcessFinish(result);
}
}
4) In your class (where you call AssyncClass, for example in your Activity) you need to implements interface you created earlier AsyncResponse.
public class MainActivity implements AsyncResponse{
{...}
void onProcessFinish(String output){
//this you will received result fired from async class of onPostExecute(result) method.
}
}
6) now you can call in MainActivity:
new MyAsyncTask(this).execute("your_url");