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How to form json array in android to send to server?

I have created an Api which is used to add multiple invitations in the database called as sendMultipleInvites.
Now I want to implement this API in android. I am trying to create an AsyncTask to call the api. I have helper class to connect to http server.
I am testing this in postman: my input should be like this:
{
"invitations": [
{
"date" : "12/08/2016",
"invitee_no" : "196756456",
"status" : "1",
"user_name" : "user10"
},
{
"date" : "12/08/2016",
"invitee_no" : "13633469",
"status" : "1",
"user_id" : "user9"
}
]
}
My serverRequest class:
public class ServerRequest {
String api;
JSONObject jsonParams;
public ServerRequest(String api, JSONObject jsonParams) {
this.api = api;
this.jsonParams = jsonParams;
}
public JSONObject sendRequest() {
try {
URL url = new URL(api);
HttpURLConnection con = (HttpURLConnection)url.openConnection();
con.setRequestMethod("POST");
con.setRequestProperty("Content-Type", "application/json");
con.setDoOutput(true);
con.setDoInput(true);
OutputStreamWriter writer = new OutputStreamWriter(con.getOutputStream());
writer.write(jsonParams.toString());
writer.close();
int responseCode = con.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
StringBuilder sb = new StringBuilder();
BufferedReader reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
String line = "";
while ( (line = reader.readLine()) != null ){
sb.append(line);
}
reader.close();
Log.d("ServerResponse", new String(sb));
return new JSONObject(new String(sb));
} else {
throw new UnexpectedServerException("Unexpected server exception with status code : "+responseCode);
}
} catch (MalformedURLException me) {
me.printStackTrace();
return Excpetion2JSON.getJSON(me);
} catch(IOException ioe) {
ioe.printStackTrace();
return Excpetion2JSON.getJSON(ioe);
} catch(UnexpectedServerException ue) {
ue.printStackTrace();
return Excpetion2JSON.getJSON(ue);
} catch (JSONException je) {
je.printStackTrace();
return Excpetion2JSON.getJSON(je);
}
}
public ServerRequest(String api) {
this.api = api;
}
}
This is my asyncTask :
public class SendMultipleInvitesAsyncTask extends AsyncTask<Map<String, String>, Void, JSONObject> {
private Context context;
public SendInviteAsyncTask(Context context) {
this.context = context;
this.progressDialog = new ProgressDialog(context);
}
#Override
protected JSONObject doInBackground(Map<String, String>... params) {
try {
String api = context.getResources().getString(R.string.server_url) + "contactsapi/sendInvite.php";
Map2JSON mjs = new Map2JSON();
JSONObject jsonParams = mjs.getJSON(params[0]);
ServerRequest request = new ServerRequest(api, jsonParams);
return request.sendRequest();
} catch (JSONException je) {
return Excpetion2JSON.getJSON(je);
}
}
#Override
protected void onPostExecute(JSONObject jsonObject) {
super.onPostExecute(jsonObject);
Log.d("ServerResponse", jsonObject.toString());
try {
int result = jsonObject.getInt("status");
String message = jsonObject.getString("message");
if (result == 1) {
//Code for having successful result for register api goes here
} else {
Toast.makeText(context, message, Toast.LENGTH_LONG).show();
}
} catch (JSONException je) {
je.printStackTrace();
Toast.makeText(context, je.getMessage(), Toast.LENGTH_LONG).show();
}
}
}
Edit:
Trying like this it is giving an error when I try to pass an arraylist to the execute method of async task.
AsyncTask:
public class SendInviteAsyncTask extends AsyncTask<ArrayList<Invitation>, Void, JSONObject> {
private ProgressDialog progressDialog;
private Context context;
public SendInviteAsyncTask(Context context) {
this.context = context;
this.progressDialog = new ProgressDialog(context);
}
#Override
protected JSONObject doInBackground(ArrayList<Invitation>... arrayLists) {
try {
String api = context.getResources().getString(R.string.server_url) + "contactsapi/sendInvite.php";
ServerRequest request = new ServerRequest(api, jsonParams);
return request.sendRequest();
} catch (JSONException je) {
return Excpetion2JSON.getJSON(je);
}
}
Activity:
public class SendMultipleInvites extends AppCompatActivity {
private ArrayList<Invitation> invitationArrayList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_send_multiple_invites);
invitationArrayList = new ArrayList<>();
Invitation invitation = new Invitation("3","17/02/2016","55165122","1","user10");
invitationArrayList.add(invitation);
invitation = new Invitation("3","17/02/2016","282751221","1","user10");
invitationArrayList.add(invitation);
new SendMultipleInvitesAsyncTask(SendMultipleInvites.this).execute(invitationArrayList);
}
}
I was using hash map to send key and values. How can I do to send a json array?
How to modify my async Task? How can I send array to an async task? Can anyone help please.. Thank you..

To pass Array to your async Task do this:
SendInviteAsyncTask extends AsyncTask<ArrayList<Sring>, Void, JSONObject>
To make a Json object you can use Gson library

try this
JSONObject obj = new JSONObject();
JSONArray req = new JSONArray();
JSONObject reqObj = new JSONObject()
reqObj.put( "ctrlId", "txt1" );
req.put( reqObj );
reqObj = new JSONObject();
reqObj.put( "ctrlId", "txt2" );
req.put( reqObj );
obj.put( "req", req );

You can really simplify your code by using a few libraries for building json and sending http requests. Here is sample code using Gson for building the json string and Volley for the http request.
I also used this fantastic project for generating the json pojo objects below. It makes really quick work of it.
Invite ivt = new Invite();
ivt.getInvitations().add( new Invitation("3","17/02/2016","55165122","1","user10"));
ivt.getInvitations().add( new Invitation("3","17/02/2016","282751221","1","user10"));
Gson gson = new Gson();
String jsonString = gson.toJson(ivt);
String url = appContext.getResources().getString(R.string.server_url) + "contactsapi/sendInvite.php";
RequestQueue queue = Volley.newRequestQueue(appContext);
StringRequest stringRequest = new StringRequest(Request.Method.POST, url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.d("TAG", "success: " + response);
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
}
});
queue.add(stringRequest);
Invite.java
public class Invite {
#SerializedName("invitations")
#Expose
private List<Invitation> invitations = new ArrayList<Invitation>();
public List<Invitation> getInvitations() {
return invitations;
}
public void setInvitations(List<Invitation> invitations) {
this.invitations = invitations;
}
}
Invitation.java
public class Invitation {
#SerializedName("date")
#Expose
private String date;
#SerializedName("invitee_no")
#Expose
private String inviteeNo;
#SerializedName("status")
#Expose
private String status;
#SerializedName("user_name")
#Expose
private String userName;
#SerializedName("user_id")
#Expose
private String userId;
public Invitation(String d, String one, String two, String three, String four) {
date = d;
inviteeNo = one;
status = two;
userName = three;
userId = four;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
public String getInviteeNo() {
return inviteeNo;
}
public void setInviteeNo(String inviteeNo) {
this.inviteeNo = inviteeNo;
}
public String getStatus() {
return status;
}
public void setStatus(String status) {
this.status = status;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getUserId() {
return userId;
}
public void setUserId(String userId) {
this.userId = userId;
}
}

Access Http response string in the Activity

I have a method name Request() in the onCreate method of the activity.
private void Request() {
new PostDataAsyncTask(textEmail, tValue).execute();
}
Iam passing two strings in it and the async class is as follows:
public class PostDataAsyncTask extends AsyncTask<String, String, String> {
GameActivity game= new GameActivity();
private String data,data1;
public PostDataAsyncTask(String textEmail, String hello) {
data = textEmail;
data1= hello;
}
long date = System.currentTimeMillis();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("MMM MM dd, yyyy h:mm a");
String dateString = simpleDateFormat.format(Long.valueOf(date));
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected String doInBackground(String... strings) {
try {
postText();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String lenghtOfFile) {
}
private void postText(){
try{
String postReceiverUrl = "http://techcube.pk/game/game.php";
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(postReceiverUrl);
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("email", data));
nameValuePairs.add(new BasicNameValuePair("score", data1));
nameValuePairs.add(new BasicNameValuePair("datetime", dateString));
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpClient.execute(httpPost);
HttpEntity resEntity = response.getEntity();
if (resEntity != null) {
String responseStr = EntityUtils.toString(resEntity).trim();
Log.v("SuccesS", "Response: " + responseStr);
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Now what i want is that i want to get the value of responseStr in my MainActivity that is generated when posttext method called.
How to show this responseStr value in the MainActivity?
Remember there is a new class that i made named as PostDataAsyncTask so how to access responseStr from this class and show it in my mainActivity as a Toast or Textview?
Please Help

You can create an interface that you pass into the method in question. For example
public interface INetworkResponse {
void onResponse(String response);
void onError(Exception e);
}
You would then need to create a concrete implementation of the interface. perhaps as a child class inside the activity that calls the AsyncTask.
public class MyActivity extends Activity {
private void Request() {
NetworkResponse response = new NetworkResponse();
new PostDataAsyncTask(textEmail, tValue, response).execute();
}
public class NetworkResponse implements INetworkResponse {
public void onResponse(String response) {
// here is where you would process the response.
}
public void onError(Exception e) {
}
}
}
Then change the async task constructor to include the new interface.
public class PostDataAsyncTask extends AsyncTask<String, String, String> {
GameActivity game= new GameActivity();
private String data,data1;
private INetworkResponse myResponse;
public PostDataAsyncTask(String textEmail, String hello, INetworkResponse response) {
data = textEmail;
data1 = hello;
myResponse = response
}
private void postText() {
// do some work
myResponse.onResponse(myResultString);
}
}

You can create a Handler as an Inner class inside your Activity to send data between your thread and UIthread:
public class YourHandler extends Handler {
public YourHandler() {
super();
}
public synchronized void handleMessage(Message msg) {
String data = (String)msg.obj;
//Manage the data
}
}
Pass this object in the header of PostDataAsyncTask
public PostDataAsyncTask(String textEmail, String hello, YourHandler mYourHandler) {
data = textEmail;
data1= hello;
this.mYourHandler = mYourHandler;
}
and send the data in postText() to the Activity:
if (resEntity != null) {
String responseStr = EntityUtils.toString(resEntity).trim();
msg = Message.obtain();
msg.obj = responseStr;
mYourHandler.sendMessage(msg);
Log.v("SuccesS", "Response: " + responseStr);
}

Get value from gson with index

I am trying to parse huge json using gson library and my main idea is to get one value from each object and save it as String. This the json file i am using. And this is the code i am using to parse the json:
public class PostsActivity extends Activity {
private static final String TAG = "PostsActivity";
private List<Post> posts;
public TextView textss;
public int i;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_posts);
textss = (TextView)findViewById(R.id.texts);
PostFetcher fetcher = new PostFetcher();
fetcher.execute();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.posts, menu);
return true;
}
private void handlePostsList(List<Post> posts) {
this.posts = posts;
runOnUiThread(new Runnable() {
#Override
public void run() {
for(Post post : PostsActivity.this.posts) {
Toast.makeText(PostsActivity.this, post.title + " " + i, Toast.LENGTH_SHORT).show();
}
}
});
}
private void failedLoadingPosts() {
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(PostsActivity.this, "Failed to load Posts. Have a look at LogCat. bls bls bls " , Toast.LENGTH_SHORT).show();
}
});
}
private class PostFetcher extends AsyncTask<Void, Void, String> {
private static final String TAG = "PostFetcher";
public static final String SERVER_URL = "http://kylewbanks.com/rest/posts";
#Override
protected String doInBackground(Void... params) {
try {
//Create an HTTP client
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(SERVER_URL);
//Perform the request and check the status code
HttpResponse response = client.execute(post);
StatusLine statusLine = response.getStatusLine();
if(statusLine.getStatusCode() == 200) {
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();
try {
for ( i = 0; i < 4; i++) {
//Read the server response and attempt to parse it as JSON
Reader reader = new InputStreamReader(content);
GsonBuilder gsonBuilder = new GsonBuilder();
gsonBuilder.setDateFormat("M/d/yy hh:mm a");
Gson gson = gsonBuilder.create();
List<Post> posts = Arrays.asList(gson.fromJson(reader, Post[].class));
content.close();
handlePostsList(posts);
}
} catch (Exception ex) {
Log.e(TAG, "Failed to parse JSON due to: " + ex);
failedLoadingPosts();
}
} else {
Log.e(TAG, "Server responded with status code: " + statusLine.getStatusCode());
failedLoadingPosts();
}
} catch(Exception ex) {
Log.e(TAG, "Failed to send HTTP POST request due to: " + ex);
failedLoadingPosts();
}
return null;
}
}
}
I am still learning and what i understand is that all values are saved in one big list and later these values are displayed as in Toast. What i am trying to do is save a value in String like i would to it with json like this:
JSONArray arr = new JSONArray(result);
JSONObject jObj = arr.getJSONObject(0);
String date = jObj.getString("NeededString");
How can i achieve this by using Gson library?

Here's what I've tried as you want.
//Read the server response and attempt to parse it as JSON
Reader reader = new InputStreamReader(content);
GsonBuilder gsonBuilder = new GsonBuilder();
gsonBuilder.setDateFormat("M/d/yy hh:mm a");
Gson gson = gsonBuilder.create();
//List<Post> posts = Arrays.asList(gson.fromJson(reader, Post[].class));
JsonArray posts = new JsonParser().parse(reader).getAsJsonArray();
// Get first element at index 0
Post post1 = gson.fromJson(posts.get(0).getAsJsonObject(), Post.class);
Log.d(TAG, "post1 .. " + post1.getTitle());
content.close();
//handlePostsList(posts);
First of all, I create a Gson JsonArray. And assign it by creating a new JsonParser which parses the reader as a JsonArray.
And then you can extract the first element of the posts by getting the element at index 0, and deserializes with respective Object.
I've used set/get for Post object so I get the title as post1.getTitle().
The log says
post1 .. Disabling Google Analytics in Development Using Only
JavaScript

Android GSON processing remote JSON runtime exception

I am attempting to write an Android app which casts JSON input. This is my sample input.
I have the following class to serve as the data container:
public class DATA {
public Long id;
public String title;
public String author;
public String url;
public String date;
public String body;
public DATA() {
// TODO Auto-generated constructor stub
}
#Override
public String toString(){
return "DATA-Oblect: ID=> " + id + "/nTITLE=> " + title;
}
}
Using the following code:
protected void doInBackground(String... url) {
try{
//create an HTTP client
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost("http://kylewbanks.com/rest/posts");//url[0]);
//perform the request and check the status code
HttpResponse response = client.execute(post);
StatusLine statusLine = response.getStatusLine();
if(statusLine.getStatusCode() == 200){
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();
content = entity.getContent();
try{
Reader reader = new InputStreamReader(content);
GsonBuilder gsonBuilder = new GsonBuilder();
gsonBuilder.setDateFormat("M/d/yy hh:mm a");
Gson gson = gsonBuilder.create();
List<DATA> Data = new ArrayList<DATA>();
Data = Arrays.asList(gson.fromJson(reader, DATA[].class));
content.close();
}catch(Exception ex){
Log.e(TAG, "JSON parse failed due to: " + ex);
}
}else{
Log.e(TAG, "Server response code: " + statusLine.getStatusCode());
}
}catch(Exception ex){
Log.e(TAG, "HTTP-Post failed due to: " + ex);
}
}
I get the following exception error:
JSON parse failed due to: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
What am I doing wrong?
Update
The following the the my main activity code:
public class MainActivity extends Activity {
private List<DATA> Data;
public static final String jsonSource = "http://kylewbanks.com/rest/posts";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
// DataRetriever("http://kylewbanks.com/rest/posts");
new DataRetriever(this.getApplicationContext()).execute(jsonSource);
}
/**
* Callback function for handling retrieved data from the
* DATARetrieve class
* #param Data
*/
public void DataListDrop(List<DATA> Data){
this.Data = Data;
Toast.makeText(MainActivity.this, "Testing ... testing!", Toast.LENGTH_SHORT).show();
runOnUiThread(new Runnable() {
#Override
public void run() {
// TODO Auto-generated method stub
for(DATA data : MainActivity.this.Data){
Toast.makeText(MainActivity.this, data.title, Toast.LENGTH_SHORT).show();
}
}
});
}
/**
* Callback function for responding no-data return from the
* DATARetrieve class
*/
private void NoData(){
runOnUiThread(new Runnable() {
#Override
public void run(){
Toast.makeText(MainActivity.this, "No data to process! Checkout LogCat.", Toast.LENGTH_SHORT).show();
}
});
}
}

Code in FOR loop not executed

I have a ProgressDialog that retrieves in background data from database by executing php script.
I'm using gson Google library. php script is working well when executed from browser:
{"surveys":[{"id_survey":"1","question_survey":"Are you happy with the actual government?","answer_yes":"50","answer_no":"20"}],"success":1}
However, ProgressDialog background treatment is not working well:
#Override
protected Void doInBackground(Void... params) {
String url = "http://192.168.1.4/tn_surveys/get_all_surveys.php";
HttpGet getRequest = new HttpGet(url);
Log.d("GETREQUEST",getRequest.toString());
try {
DefaultHttpClient httpClient = new DefaultHttpClient();
Log.d("URL1",url);
HttpResponse getResponse = httpClient.execute(getRequest);
Log.d("GETRESPONSE",getResponse.toString());
final int statusCode = getResponse.getStatusLine().getStatusCode();
Log.d("STATUSCODE",Integer.toString(statusCode));
Log.d("HTTPSTATUSOK",Integer.toString(HttpStatus.SC_OK));
if (statusCode != HttpStatus.SC_OK) {
Log.w(getClass().getSimpleName(), "Error " + statusCode + " for URL " + url);
return null;
}
HttpEntity getResponseEntity = getResponse.getEntity();
Log.d("RESPONSEENTITY",getResponseEntity.toString());
InputStream httpResponseStream = getResponseEntity.getContent();
Log.d("HTTPRESPONSESTREAM",httpResponseStream.toString());
Reader inputStreamReader = new InputStreamReader(httpResponseStream);
Gson gson = new Gson();
this.response = gson.fromJson(inputStreamReader, Response.class);
}
catch (IOException e) {
getRequest.abort();
Log.w(getClass().getSimpleName(), "Error for URL " + url, e);
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
Log.d("HELLO","HELLO");
StringBuilder builder = new StringBuilder();
Log.d("STRINGBUILDER","STRINGBUILDER");
for (Survey survey : this.response.data) {
String x= survey.getQuestion_survey();
Log.d("QUESTION",x);
builder.append(String.format("<br>ID Survey: <b>%s</b><br> <br>Question: <b>%s</b><br> <br>Answer YES: <b>%s</b><br> <br>Answer NO: <b>%s</b><br><br><br>", survey.getId_survey(), survey.getQuestion_survey(),survey.getAnswer_yes(),survey.getAnswer_no()));
}
Log.d("OUT FOR","OUT");
capitalTextView.setText(Html.fromHtml(builder.toString()));
progressDialog.cancel();
}
HELLO Log is displayed.
STRINGBUILDER Log is displayed.
QUESTION Log is NOT displayed.
OUT FOR Log is displayed.
Survey Class:
public class Survey {
int id_survey;
String question_survey;
int answer_yes;
int answer_no;
public Survey() {
this.id_survey = 0;
this.question_survey = "";
this.answer_yes=0;
this.answer_no=0;
}
public int getId_survey() {
return id_survey;
}
public String getQuestion_survey() {
return question_survey;
}
public int getAnswer_yes() {
return answer_yes;
}
public int getAnswer_no() {
return answer_no;
}
}
Response Class:
public class Response {
ArrayList<Survey> data;
public Response() {
data = new ArrayList<Survey>();
}
}
Any help please concerning WHY the FOR loop is not executed.
Thank you for helping.

Any help please concerning WHY the FOR loop is not executed.
Simply put: data is empty. (So there is nothing for the loop to iterate over...)
Try something like this, from GSON's documentation:
Type listType = new TypeToken<List<String>>() {}.getType();
List<String> target = new LinkedList<String>();
target.add("blah");
Gson gson = new Gson();
String json = gson.toJson(target, listType);
List<String> target2 = gson.fromJson(json, listType);
I haven't used GSON myself, but there are other examples of how to read lists:
Android gson deserialization into list
GSON : custom object deserialization

Your onPostExecute takes in a parameter called result. Your for loop iterates over the elements in an instance variable called response. Are they supposed to be the same?