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JSON Parser Error : http client failure [closed]

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Im learning the JSON Parser. I follow the androidhive tutorial and copy its code, but sadly, i cannot. It does not display anything and has these type of errors:
11-22 17:27:12.132: E/AndroidRuntime(1938): Caused by: android.os.NetworkOnMainThreadException
Can anyone help me with this problem? Thanks.
JSONPaser
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
MainActivity
import android.view.Menu;
import java.util.ArrayList;
import java.util.HashMap;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
public class MainActivity extends ListActivity{
// url to make request
private static String url = "http://api.androidhive.info/contacts/";
// JSON Node names
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_ADDRESS = "address";
private static final String TAG_GENDER = "gender";
private static final String TAG_PHONE = "phone";
private static final String TAG_PHONE_MOBILE = "mobile";
private static final String TAG_PHONE_HOME = "home";
private static final String TAG_PHONE_OFFICE = "office";
// contacts JSONArray
JSONArray contacts = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList = new ArrayList<HashMap<String, String>>();
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
// Getting Array of Contacts
contacts = json.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for(int i = 0; i < contacts.length(); i++){
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_GENDER);
// Phone number is agin JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
String home = phone.getString(TAG_PHONE_HOME);
String office = phone.getString(TAG_PHONE_OFFICE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_ID, id);
map.put(TAG_NAME, name);
map.put(TAG_EMAIL, email);
map.put(TAG_PHONE_MOBILE, mobile);
// adding HashList to ArrayList
contactList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(this, contactList,
R.layout.list_item,
new String[] { TAG_NAME, TAG_EMAIL, TAG_PHONE_MOBILE }, new int[] {
R.id.name, R.id.email, R.id.mobile });
setListAdapter(adapter);
// selecting single ListView item
ListView lv = getListView();
// Launching new screen on Selecting Single ListItem
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
String cost = ((TextView) view.findViewById(R.id.email)).getText().toString();
String description = ((TextView) view.findViewById(R.id.mobile)).getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_EMAIL, cost);
in.putExtra(TAG_PHONE_MOBILE, description);
startActivity(in);
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
<uses-permission android:name="android.permission.INTERNET" /> is use in Manifest
How can i use AsyncTask or Thread with Handler to solve the error ?? do i need to delete my JSON Parser class ??
things i tried so far:
i switched i target SDK version to fit my emulator but it still
doesn't work
i run the project on my phone (Samsung) and emulator (Genymotion)
it show the same error
i tried to test another method without JSON Array
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;
import android.util.Log;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
public class Main extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
try{ //try1 start
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// this is our TextView element, obtained by id from our XML layout
TextView myListView = (TextView)findViewById(R.id.netResult);
//lets try to connect
try{ //try2 start
//create a new client object
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://ephemeraltech.com/demo/android_tutorial20.php");
//execute the post and get the response object
HttpResponse response = httpclient.execute(httppost);
//get the message from the response
HttpEntity entity = response.getEntity();
//get the content of the message
InputStream webs = entity.getContent();
//convert response to string
try{ //try3 start
BufferedReader reader = new BufferedReader(new InputStreamReader(webs,"utf-8"),8);
//read one line of the response
myListView.setText(reader.readLine());
//slow our inputStream
webs.close();
}//try3 end
catch (Exception e){//catch 3 start
Log.e("log_result", "Error converting result "+e.toString());
}//catch 3 end
} //try2 end
catch (Exception e){//catch 2 start
Log.e("log_connect", "Error in http connection "+e.toString());
}
}//try1 end
catch (Exception e){ //catch 1 start
//this is the lie of code that sends a real error message to the log
Log.e("ERROR", "ERROR IN CODE: "+e.toString());
e.printStackTrace();
}//catch 1 end
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
in this code the LogCat catch my second try and print log_connect, Error in http connection

You have a NetworkOnMainThreadException error.
That means you have directly run your code on onCreate method:
But you can't update your data directly on MainUI thread.
For that you have to use AsyncTask or Thread with Handler or update your UI with runOnUiThread()
You can go with this:
http://www.vogella.com/articles/AndroidBackgroundProcessing/article.html

Did you read the stack trace at all?
Caused by: android.os.NetworkOnMainThreadException
If you had even googled with "NetworkOnMainThreadException" you would have got the answer.
In short, the reason is you are performing an HTTP request on the main thread which is a bad practise actually. Android recently has become more restrictive and throws an exception.
What you need is something like this:
new AsyncTask<CustomParamClass, Void, String>() {
#Override
protected String doInBackground(final CustomerParamClass... params) {
//use params to get the data and make an HHTP Request.
}
#Override
protected void onPostExecute(final String params) {
// This is invoked on the main thread. Communicate here.
}
}.execute(<pass some params here>);

More JSON and Android Problems

I'm trying to parse some JSON in my android APP. However I'm getting two errors. First one is "Value of type string cannot be converted to JSON Object" (this error I have gotten rid of by changing a few lines of code, but likely messed something up but I don't know yet cause the app is running). The second error is a null pointer error.
I know there is a lot of code on here about this already by they all use the hive tutorial to jump straight into an array. I've tried editing this code to get my JSON into a ListView but just can't quite get it. I think my problem is that I'm returning a JSONObject in the parser, which is calling my very first object (Identified), then my code immediately jumps into the array, which there isn't one because Identified isn't the array, information is. So how, in code, can I get the object of Identified, and then get the object of information (thereby jumping into the information array with the above code)? I've never done JSON parsing so it's kind of difficult for me. I'm pretty sure this is the problem, I just don't know how to get around it. It's driving me crazy. Everything I can find on JSON/Android uses a JSON that begins with an array, which my code would take care of. I just can't figure out how to do the above: get the second object's array. Any help would be extremely appreciated. I've been racking my brain for days trying different things. The app runs sometimes and doesn't show anything on screen, other times the app just crashes with an error that says String cannot convert JSONObject, and a few times I got null pointer errors. Like I mentioned, I think it's because I'm trying to call the array on "Identified" when I should be calling it on "information". But I can't figure out how to get past Identified and then jump into the information array. I'm sure it's just a few lines of code in the right place, but I don't know where.
The JSON is as follows:
{
"identified": "yes",
"Information":
[
{
"state": "Arkansas",
"type": "landlocked",
"additionalinfo": "{ search: 'online', website: 'http://states.arkansas.com', latitudeandlongitude: '93905, 63550}",
"outdoorfun": "yes",
"cold": "no"
},
{
"state": "chicago",
"type": "windy",
"additionalinfo": "{ search: 'online', website: 'http://states.chicago.com', latitudeandlongitude: '23905, 45355}",
"outdoorfun": "no",
"cold": "yes"
}
]
}
And the main part of the Activity class code is below:
// JSON Node names
private static final String TAG_IDENTIFIED = "id";
private static final String TAG_INFORMATION = "information";
private static final String TAG_STATE = "state";
private static final String TAG_TYPE = "type";
private static final String TAG_ADDITIONALINFO = "additionalinfo";
private static final String TAG_OUTDOORFUN = "outdoorfun";
private static final String TAG_COLD = "cold";
// contacts JSONArray
JSONArray information = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Hashmap for ListView
ArrayList<HashMap<String, String>> stateList = new ArrayList<HashMap<String, String>>();
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try{
for(int i = 0; i < information.length(); i++){
information =json.getJSONArray(TAG_INFORMATION);
JSONObject c = information.getJSONObject(i);
// Storing each json item in variable
String name = c.getString(TAG_STATE);
String type = c.getString(TAG_TYPE);
// Phone number is agin JSON Object
JSONObject additionalinfo = c.getJSONObject(ADDITIONALINFO);
String outdoorfun = c.getString(TAG_OUTDOORFUN);
String cold = c.getString(TAG_COLD);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_NAME, name);
map.put(TAG_TYPE, type);
map.put(TAG_OUTDOORFUN, outdoorfun);
informationList.add(map);
}
}
catch (JSONException e) {
e.printStackTrace();
}
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(this, informationList,
R.layout.list_item,
new String[] {TAG_NAME, TAG_TYPE, TAG_OUTDOORFUN }, new int[] {
R.id.name, R.id.type, R.id.outdoorfun });
setListAdapter(adapter);
// selecting single ListView item
ListView lv = getListView();
// Launching new screen on Selecting Single ListItem
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
String type = ((TextView) view.findViewById(R.id.type)).getText().toString();
String outdoorfun = ((TextView) view.findViewById(R.id.outdoorfun)).getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_TYPE, type);
in.putExtra(TAG_OUTDOORFUN, outdoorfun);
startActivity(in);
}
});
The Parser is here:
herepackage com.androidhive.jsonparsing;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
public class JSONParser extends Activity {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
And the Single List Activity is Here:
package com.androidhive.jsonparsing;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
public class SingleMenuItemActivity extends Activity {
// JSON node keys
private static final String TAG_ID = "id";
private static final String TAG_INFORMATION = "information";
private static final String TAG_STATE = "state";
private static final String TAG_TYPE = "type";
private static final String TAG_ADDITIONALINFO = "additionalinfo";
private static final String TAG_OUTDOORFUN = "outdoorfun";
private static final String TAG_COLD = "cold";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.single_list_item);
// getting intent data
Intent in = getIntent();
// Get JSON values from previous intent
String name = in.getStringExtra(TAG_NAME);
String type = in.getStringExtra(TAG_TYPE);
String outdoorfun = in.getStringExtra(TAG_OUTDOORFUN);
// Displaying all values on the screen
TextView lblName = (TextView) findViewById(R.id.name_label);
TextView lblType = (TextView) findViewById(R.id.type_label);
TextView lblOutdoorfun = (TextView) findViewById(R.id.outdoorfun_label);
lblName.setText(name);
lblType.setText(type);
lblOutdoorfun.setText(outdoorfun);
}
}

I think you might want TAG_INFORMATION = "Information" or your JSON to read
"information":
[
Your cases don't match.
I also think you might need to retrieve the information array outside the for loop (that is, json.getJSONArray should probably be outside the for loop.

ProgressDialog in android not shown even with Async Task

Hello # All out there :)
I am having a little problem. I want to show a ProgressDialog when I click on Login but nothing is shown it just does the Task without the ProgressDialog. I am using a AsyncTask and opening the ProgressDialog in that thread but nothing comes up. Here is my Source Code:
It is called like this:
ProgressDialog progress = new ProgressDialog(mainActivity);
progress.setMessage("Sie werden registriert...");
jsonParser = new JSONParser(progress, url_create_user, "POST", params);
And this is the JSONParser Class:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.params.ClientPNames;
import org.apache.http.client.params.CookiePolicy;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.util.Log;
public class JSONParser extends AsyncTask<Context, Void, JSONObject>{
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
String url = "";
String method = "";
List<NameValuePair> parameters;
ProgressDialog prog;
// constructor
public JSONParser(ProgressDialog prog, String url, String method, List<NameValuePair> param) {
this.url = url;
this.method = method;
this.parameters = param;
this.prog = prog;
}
private Handler handler = new Handler() {
#Override
public void handleMessage(Message msg) {
if (msg.what == 0)
{
prog.show();
}
else
{
prog.dismiss();
}
}
};
#Override
protected JSONObject doInBackground(Context... params) {
try {
handler.sendEmptyMessage(0);
// Überprüfen welche Request Methode benutzt werden soll
if(method == "POST"){
DefaultHttpClient httpClient = new DefaultHttpClient();
httpClient.getParams().setParameter(ClientPNames.COOKIE_POLICY,
CookiePolicy.BROWSER_COMPATIBILITY);
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(this.parameters));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}else if(method == "GET"){
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(this.parameters, "utf-8");
url += "?" + paramString;
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
//Stream in ein String umwandeln
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Fehler!", "Fehler mein umwandeln von Stream in String: " + e.toString());
}
// JSON Object parsen
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error beim parsen " + e.toString());
}
handler.sendEmptyMessage(1);
// Das JSONObject zurückgeben
return jObj;
}
}

see the following example code of JSON parser with async task
package com.androidhive.jsonparsing;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
public class AndroidJSONParsingActivity extends ListActivity {
// url to make request
private static String url = "http://api.androidhive.info/contacts/";
// JSON Node names
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_ADDRESS = "address";
private static final String TAG_GENDER = "gender";
private static final String TAG_PHONE = "phone";
private static final String TAG_PHONE_MOBILE = "mobile";
private static final String TAG_PHONE_HOME = "home";
private static final String TAG_PHONE_OFFICE = "office";
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// contacts JSONArray
JSONArray contacts = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new GetEventsTask().execute("");
}
protected class GetEventsTask extends
AsyncTask<String, Integer, ArrayList<HashMap<String, String>>> {
protected ArrayList<HashMap<String, String>> contactList;
private final ProgressDialog dialog = new ProgressDialog(
AndroidJSONParsingActivity.this);
//PreExecute Method
protected void onPreExecute() {
this.dialog.setMessage("Loading, Please Wait..");
this.dialog.setCancelable(false);
this.dialog.show();
}
//doInBackground Method
#Override
protected ArrayList<HashMap<String, String>> doInBackground(
String... params) {
contactList = new ArrayList<HashMap<String, String>>();
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
BufferedReader reader = new BufferedReader(
new InputStreamReader(is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
Log.i("json objects",""+json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
try {
// Getting Array of Contacts
contacts = jObj.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_GENDER);
// Phone number is agin JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
String home = phone.getString(TAG_PHONE_HOME);
String office = phone.getString(TAG_PHONE_OFFICE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_ID, id);
map.put(TAG_NAME, name);
map.put(TAG_EMAIL, email);
map.put(TAG_PHONE_MOBILE, mobile);
// adding HashList to ArrayList
contactList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
return contactList;
}
//onPostExecute Method
protected void onPostExecute(ArrayList<HashMap<String, String>> result) {
ListAdapter adapter = new SimpleAdapter(getApplicationContext(),
contactList, R.layout.list_item, new String[] { TAG_NAME,
TAG_EMAIL, TAG_PHONE_MOBILE }, new int[] {
R.id.name, R.id.email, R.id.mobile });
// selecting single ListView item
ListView lv = getListView();
lv.setAdapter(adapter);
// Launching new screen on Selecting Single ListItem
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
String cost = ((TextView) view.findViewById(R.id.email)).getText().toString();
String description = ((TextView) view.findViewById(R.id.mobile)).getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(),SingleMenuItemActivity.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_EMAIL, cost);
in.putExtra(TAG_PHONE_MOBILE, description);
startActivity(in);
}
});
if (this.dialog.isShowing()) {
this.dialog.dismiss();
}
}
}
}
Let me know your problem is resolved or not?

you can't compare == between 2 string
Use:
method.equals("POST");

I am doing everything in background using doInBackground() where to use onPostExecute()

I am trying to show JSON data into Mapview, but always getting blank map.
I knew that to populate I need to use onPostExecute() in my activity but I am confuse where I need to put onPostExecute() method and what are the lines I need to place in that.
Please someone make these changes, below I have written my code, advance thanks to viewers and readers
JSON Data:-
{
"maps": [
{
"title": "Place One",
"latitude" : "46.483742",
"longitude" : "7.663157",
"country": "Switzerland"
},
{
"title" : "Place Two",
"latitude" : "59.25235",
"longitude" : "18.465536",
"country" : "Sweden"
},
{
"title" : "Place Three",
"latitude" : "56.404182",
"longitude" : "-3.818855",
"country" : "Scotland"
}
]
}
Activity Code:-
mapOverlays = mapView.getOverlays();
drawable = getResources().getDrawable(R.drawable.ic_launcher);
itemizedOverlay = new SimpleItemizedOverlay (drawable, mapView);
itemizedOverlay.setShowClose(false);
itemizedOverlay.setShowDisclosure(true);
itemizedOverlay.setSnapToCenter(false);
class DownloadWebPageTask extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... urls) {
HttpClient client = new DefaultHttpClient();
// Perform a GET request for a JSON list
HttpUriRequest request = new HttpGet("https://dl.***.com/maps.json");
// Get the response that sends back
HttpResponse response = null;
try {
response = client.execute(request);
} catch (ClientProtocolException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// Convert this response into a readable string
String jsonString = null;
try {
jsonString = StreamUtils.convertToString(response.
getEntity().getContent());
} catch (IllegalStateException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// Create a JSON object that we can use from the String
JSONObject json = null;
try {
json = new JSONObject(jsonString);
} catch (JSONException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try{
JSONArray jsonArray = json.getJSONArray("maps");
Log.e("log_tag", "Opening JSON Array ");
for
(int i=0;i < jsonArray.length();i++){
JSONObject jsonObject = jsonArray.getJSONObject(i);
String latitude = jsonObject.getString("latitude");
String longitude = jsonObject.getString("longitude");
String title = jsonObject.getString("title");
String country = jsonObject.getString("country");
double lat = Double.parseDouble(latitude);
double lng = Double.parseDouble(longitude);
Log.e("log_tag", "ADDING GEOPOINT"+title);
point = new GeoPoint(
(int) (lat * 1E6),
(int) (lng * 1E6));
OverlayItem overlayItem = new OverlayItem(point, title,
country);
itemizedOverlay.addOverlay(overlayItem);
}
}catch(JSONException e) {
Log.e("log_tag", "Error parsing data "+e.toString());
}
itemizedOverlay.populateNow();
mapOverlays.add(itemizedOverlay);
if (savedInstanceState == null) {
MapController controller = mapView.getController();
controller.setCenter(point);
controller.setZoom(7);
} else {
// example restoring focused state of overlays
int focused;
focused = savedInstanceState.getInt("focused_1", -1);
if (focused >= 0) {
itemizedOverlay.setFocus
(itemizedOverlay.getItem(focused));
}
}
return jsonString; }
}
}

I understand your problem, the following code is how to get the json data and showing in a listview. It is helpful for you to show when you will write the PostExecute Method. you have to set the overlay items in PostExecute method.
package com.androidhive.jsonparsing;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
public class AndroidJSONParsingActivity extends ListActivity {
// url to make request
private static String url = "http://api.androidhive.info/contacts/";
// JSON Node names
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_ADDRESS = "address";
private static final String TAG_GENDER = "gender";
private static final String TAG_PHONE = "phone";
private static final String TAG_PHONE_MOBILE = "mobile";
private static final String TAG_PHONE_HOME = "home";
private static final String TAG_PHONE_OFFICE = "office";
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// contacts JSONArray
JSONArray contacts = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new GetEventsTask().execute("");
}
protected class GetEventsTask extends
AsyncTask<String, Integer, ArrayList<HashMap<String, String>>> {
protected ArrayList<HashMap<String, String>> contactList;
private final ProgressDialog dialog = new ProgressDialog(
AndroidJSONParsingActivity.this);
//PreExecute Method
protected void onPreExecute() {
this.dialog.setMessage("Loading, Please Wait..");
this.dialog.setCancelable(false);
this.dialog.show();
}
//doInBackground Method
#Override
protected ArrayList<HashMap<String, String>> doInBackground(
String... params) {
contactList = new ArrayList<HashMap<String, String>>();
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
BufferedReader reader = new BufferedReader(
new InputStreamReader(is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
Log.i("json objects",""+json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
try {
// Getting Array of Contacts
contacts = jObj.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_GENDER);
// Phone number is agin JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
String home = phone.getString(TAG_PHONE_HOME);
String office = phone.getString(TAG_PHONE_OFFICE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_ID, id);
map.put(TAG_NAME, name);
map.put(TAG_EMAIL, email);
map.put(TAG_PHONE_MOBILE, mobile);
// adding HashList to ArrayList
contactList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
return contactList;
}
//onPostExecute Method
protected void onPostExecute(ArrayList<HashMap<String, String>> result) {
// selecting single ListView item
ListView lv = getListView();
ListAdapter adapter = new SimpleAdapter(getApplicationContext(),
contactList, R.layout.list_item, new String[] { TAG_NAME,
TAG_EMAIL, TAG_PHONE_MOBILE }, new int[] {
R.id.name, R.id.email, R.id.mobile });
lv.setListAdapter(adapter);
// Launching new screen on Selecting Single ListItem
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name))
.getText().toString();
String cost = ((TextView) view.findViewById(R.id.email))
.getText().toString();
String description = ((TextView) view
.findViewById(R.id.mobile)).getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(),
SingleMenuItemActivity.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_EMAIL, cost);
in.putExtra(TAG_PHONE_MOBILE, description);
startActivity(in);
}
});
//Dismiss the dialog
if (this.dialog.isShowing()) {
this.dialog.dismiss();
}
}
}
}

Parsing JSON in Android

I am about to work with JSON for the first time. Previously I worked on parsing XML in Android. How is it different with JSON? Suggest me some good tutorials for the same.
Stone

Do you mean JSON? You can parse JSON very easily on Android. You can either use the built-in org.json parser or use a third-party library, such as google-gson, or any other Java JSON library.

You actually mean JSON right? If you're wondering about the JSON structure http://www.json.org/ is a great place to start.
I have never used JSON with android, but Googling give me this looks-promising tutorial http://www.javacodegeeks.com/2011/01/android-json-parsing-gson-tutorial.html

full code which run succesfully..........
package com.example.jsonparsingapp;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ListActivity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
public class AndroidJSONParsingActivity extends ListActivity {
// url to make request
private static String url = "http://api.androidhive.info/contacts/";
// JSON Node names
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_ADDRESS = "address";
private static final String TAG_GENDER = "gender";
private static final String TAG_PHONE = "phone";
private static final String TAG_PHONE_MOBILE = "mobile";
private static final String TAG_PHONE_HOME = "home";
private static final String TAG_PHONE_OFFICE = "office";
JSONObject json;
// contacts JSONArray
JSONArray contacts = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new RetreiveFeedTask().execute("hbhbh");
}
class RetreiveFeedTask extends AsyncTask<String,String,String> {
private Exception exception;
RetreiveFeedTask()
{
}
#Override
protected void onPreExecute( ) {
// TODO Auto-generated method stub
super.onPreExecute();
}
protected String doInBackground(String... urls)
{
try{
System.out.println("in doinbackground");
StringBuilder builder = new StringBuilder();
HttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet("http://api.androidhive.info/contacts/");
try {
HttpResponse response = client.execute(httpGet);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) {
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(content));
String line;
while ((line = reader.readLine()) != null) {
builder.append(line);
}
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
json=new JSONObject(builder.toString());
System.out.println("string issssss"+builder.toString());
System.out.println("in doinbackground end");
}catch(Exception e)
{
e.printStackTrace();
}
return "hi";
}
protected void onPostExecute(String s) {
// TODO: check this.exception
// TODO: do something with the feed
System.out.println("postexecute");
doWork();
}
}
public void doWork()
{
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList = new ArrayList<HashMap<String, String>>();
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
//JSONObject json = jParser.getJSONFromUrl(url);
//System.out.println("json is"+json);
try {
// Getting Array of Contacts
contacts = json.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for(int i = 0; i < contacts.length(); i++){
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_GENDER);
// Phone number is agin JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
String home = phone.getString(TAG_PHONE_HOME);
String office = phone.getString(TAG_PHONE_OFFICE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_ID, id);
map.put(TAG_NAME, name);
map.put(TAG_EMAIL, email);
map.put(TAG_PHONE_MOBILE, mobile);
// adding HashList to ArrayList
contactList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(this, contactList,
R.layout.list_item,
new String[] { TAG_NAME, TAG_EMAIL, TAG_PHONE_MOBILE }, new int[] {
R.id.name, R.id.email, R.id.mobile });
setListAdapter(adapter);
// selecting single ListView item
ListView lv = getListView();
// Launching new screen on Selecting Single ListItem
}
}