Develop Reference

My android studio app keeps crashing after using a background method to read a json from my fragment

I am making an app using the Kitsu API. Here in this moment I have a fragment that allows me to search different anime using the api to get information such as name, synopsis, etc. After parsing the information I proceed to go back to my main activity to pass it to my new fragment, but it crashes the moment I initialize the method to go back to my main activity. My question is how do I use a fragment to read a JSON with a background class using ASYNCTASK and display it in a new fragment?
I have noticed that it jumps around a lot from my fragment, in an activity different from my main, to a class running in the background, to my main, to my fragment. Below are images of my code. Thank you very much.
Search fragment code, Main Activity search related methods, Search results background tasks, Search Results Fragment. To clarify It stops before I get to the string I labeled crashpoint and doesn't make it to the search results fragment. I felt like it would be handy to have that bit of code in there. Here is the error I get with my code when I run it.

You don't need to create a new fragment after reading JSON. Just to post an simple code that read JSON with async task:
package com.example.compsci_734t;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.util.ArrayList;
import java.util.zip.GZIPInputStream;
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.Activity;
import android.app.ListActivity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class People extends Activity{
ArrayList<String> items = new ArrayList<String>();
static InputStream is = null;
//private static String url = "";
//private static String url = "http:...";
private static String url = "http....";
//URL requestUrl = new URL(url);
JSONArray people = null;
private static final String TAG_COURSES = "Courses";
static JSONObject jObj = null;
static String json = "";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.people);
new MyTasks().execute();
}
private class MyTasks extends AsyncTask<URL, Void, JSONObject> {
#Override
protected JSONObject doInBackground(URL... urls) {
// return loadJSON(url);
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
//HttpPost httpPost = new HttpPost(url);
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();
}
try {
/*BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "UTF-8"), 8);*/
InputStream inputStream = is;
GZIPInputStream input = new GZIPInputStream(inputStream);
InputStreamReader reader = new InputStreamReader(input);
BufferedReader in = new BufferedReader(reader);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = in.readLine()) != null) {
sb.append(line);
//System.out.println(line);
}
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 {
JSONArray people = new JSONArray(json);
//JSONArray people = new JSONArray(json);
for (int i = 0; i < people.length(); i++) {
//System.out.println(courses.getJSONObject(i).toString());
JSONObject p = people.getJSONObject(i);
// Storing each json item in variable
String person_id = p.getString("someString1");
items.add(person_id);
/*Log.v("--", "People: \n" + "\n UPI: " + person_id);*/
}
//jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
protected void onPostExecute(JSONObject json) {
ListView myListView = (ListView)findViewById(R.id.peopleList);
myListView.setAdapter(new ArrayAdapter(getApplicationContext(), android.R.layout.simple_list_item_1, items));
}
}
The sample code was taken from this answer.

Error parsing dataorg.json.JSONException: Value <br of type java.lang.String cannot be converted to JSONObject

i'm trying to make android food order for my thesis and because this error i'm running out of time :(
error on logcat :
Error parsing dataorg.json.JSONException: Value cannot be converted to JSONObject
org.json.JSONException: Value to JSONObject
here's my JSONParser :
package com.makanan.restotradisional;
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.utils.URLEncodedUtils;
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 = "";
public JSONParser() {
}
// fungsi abil json url lewat method HTTP POST atau GET
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params) {
try {
if (method == "POST") {
// jika request method adalah POST
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} else if (method == "GET") {
// jika request method adalah GET
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(params, "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();
}
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 {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data" + e.toString());
e.printStackTrace();
}
return jObj;
}
}
this my PHP & Java : http://www.4shared.com/rar/1lGplX19ba/Java_and_PHP.html
and this is my database on phpmyadmin :http://www.4shared.com/rar/y_UMtL7_ce/rumah_makan.html
please help me

Remove any of the <br> statements or echo statements from your php file except the one that you are using to pass json..
Check the output of your file in browser, remove all the unwanted things other than json..

Please print and check if your string json is in right format as expected by the JSONObject constructor. Per documentation, valid json string to construct JSONObject should be -- A string beginning with { (left brace) and ending with } (right brace).
Please refer this.

Go inside JSONParser and do this so u see in logcat whats comming from php. Probably its a php error.
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
//This line is what u need to add
Log.d("Whats wrong?", json.toString());
Log.e("JSON Parser", "Error parsing data " + e.toString());
}

JSON reads me only objects, no arrays

I'm using Eclipse, for an application where I have to read a JSON file from an URL.
The code I'm using is this one:
http://collegewires.com/android/2012/06/json-parsing-in-android/
Ok, the CLASS which I'm using for reading JSON files is called Parser.java:
package com.cw.json;
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;
public class Parser {
static InputStream is = null;
static JSONObject jsonObject = null;
static String json = "";
// class constructor
public Parser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException exception) {
exception.printStackTrace();
} catch (ClientProtocolException exception) {
exception.printStackTrace();
} catch (IOException exception) {
exception.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sBuilder = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sBuilder.append(line + "\n");
}
is.close();
json = sBuilder.toString();
} catch (Exception exception) {
exception.printStackTrace();
}
// Parsing the string to a JSON object
try {
jsonObject = new JSONObject(json);
} catch (JSONException exception) {
exception.printStackTrace();
}
// JSON String
return jsonObject;
}
}
I was using this code for reading a JSON file which is directly an ARRAY, but the code gives me an error.
My question is: is it possible to read an Array instead always reading an Object??
maybe using another class?

Try to modify your Parser.java to this, so you gat a Array not a Object. And please buy you a JAVA Book for beginners, so you do learn how to speak JAVA
public JSONArray getJSONFromUrl(String url) {
....
static JSONArray jsonArray = null;
....
// Parsing the string to a JSON Array
try {
jsonArray = new JSONArray(json);
} catch (JSONException exception) {
exception.printStackTrace();
}
return jsonArray;
}

JSONArray error while connecting android to mobile db

I am trying to connect to my online database with android. After following a tutorial I came up with this piece of code:
package com.example.helloandroid;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.*;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
public class HelloAndroid extends Activity {
JSONArray jArray;
String result = null;
InputStream is = null;
StringBuilder sb=null;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
try{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://192.168.1.4/~jasptack/Software%20engineering/connector.php");
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
}catch(Exception e){
Log.e("log_tag", "Error in http connection"+e.toString());
}
//convert response to string
try{
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
sb = new StringBuilder();
sb.append(reader.readLine() + "\n");
String line="0";
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result=sb.toString();
}catch(Exception e){
Log.e("log_tag", "Error converting result "+e.toString());
}
//parse json data
try{
JSONArray jArray = new JSONArray(result);
for(int i=0;i<jArray.length();i++){
JSONObject json_data = jArray.getJSONObject(i);
Log.i("log_tag","x-co: "+json_data.getInt("x-coordinaat")+
", straat: "+json_data.getString("straat")
);
}
}catch(JSONException e){
Log.e("log_tag", "Error parsing data "+e.toString());
}
}
}
When I execute this, I get the following error:
12-04 23:25:07.711: E/log_tag(353): Error parsing data org.json.JSONException: Value
Can anybody help with this? Thanks!

This happens if the JSON string is malformed. Make sure that the String result is a valid JSONArray (Should start with '['). Also, you can try mapping result to a JSONObject instead. If these are fine, one of the elements inside the JSONArray is malformed.

I once tried parsing a JSON String returned by my web service. Here is what I did:
The response I got from the web service was:
{"checkrecord":[{"rollno":"abc2","percentage":40,"attended":12,"missed":34}],"Table1":[]}
In order to parse I did the following:
JSONObject jsonobject = new JSONObject(result);
JSONArray array = jsonobject.getJSONArray("checkrecord");
int max = array.length();
for (int j = 0; j < max; j++)
{
JSONObject obj = array.getJSONObject(j);
JSONArray names = obj.names();
for (int k = 0; k < names.length(); k++)
{
String name = names.getString(k);
String value= obj.getString(name);
}
My JSONObject looks like this:
{"Table1":[],"checkrecord":[{"missed":34,"attended":12,"percentage":40,"rollno":"abc2"}]}
This is what the #500865 was trying to suggest. I just gave a code sample to you. Check your result first and determine whether it is valid. Also check JSONArray result.
If possible post it over here.
Hope it helps
Cheers

HTTPclient POST with problematic web site

I'm trying to retrive some data from a web site.
I wrote a java class which seems to work pretty fine with many sites but it doesn't work with this particular site, which use extensive javascript in the input fomr.
As you can see from the code I specified the input fields taking the name from the HTML source, but maybe this website doesn't accept POST request of this kind?
How can I simulate an user-interaction to retrieve the generated HTML?
package com.transport.urlRetriver;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
public class UrlRetriver {
String stationPoller (String url, ArrayList<NameValuePair> params) {
HttpPost postRequest;
HttpResponse response;
HttpEntity entity;
String result = null;
DefaultHttpClient httpClient = new DefaultHttpClient();
try {
postRequest = new HttpPost(url);
postRequest.setEntity((HttpEntity) new UrlEncodedFormEntity(params));
response = httpClient.execute(postRequest);
entity = response.getEntity();
if(entity != null){
InputStream inputStream = entity.getContent();
result = convertStreamToString(inputStream);
}
} catch (Exception e) {
result = "We had a problem";
} finally {
httpClient.getConnectionManager().shutdown();
}
return result;
}
void ATMtravelPoller () {
ArrayList<NameValuePair> params = new ArrayList<NameValuePair>(2);
String url = "http://www.atm-mi.it/it/Pagine/default.aspx";
params.add(new BasicNameValuePair("ctl00$SPWebPartManager1$g_afa5adbb_5b60_4e50_8da2_212a1d36e49c$txt_address_s", "Viale romagna 1"));
params.add(new BasicNameValuePair("ctl00$SPWebPartManager1$g_afa5adbb_5b60_4e50_8da2_212a1d36e49c$txt_address_e", "Viale Toscana 20"));
params.add(new BasicNameValuePair("sf_method", "POST"));
String result = stationPoller(url, params);
saveToFile(result, "/home/rachele/Documents/atm/out4.html");
}
static void saveToFile(String toFile, String pos){
try{
// Create file
FileWriter fstream = new FileWriter(pos);
BufferedWriter out = new BufferedWriter(fstream);
out.write(toFile);
//Close the output stream
out.close();
}catch (Exception e){//Catch exception if any
System.err.println("Error: " + e.getMessage());
}
}
private static String convertStreamToString(InputStream is) {
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder stringBuilder = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
stringBuilder.append(line + "\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return stringBuilder.toString();
}
}

At my point of view, there could be javascript generated field with dynamic value for preventing automated code to crawl the site. Send concrete site you want to download.