Develop Reference

How to pass a variable from JSONArray

I have code that receives a variable from an external JSON array
import java.io.IOException;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.os.Bundle;
import android.os.StrictMode;
import android.widget.Toast;
public class ListviewActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String json_str = getJsonData();
try{
JSONArray jArray = new JSONArray(json_str);
JSONObject json = null;
json = jArray.getJSONObject(0);
String date=json.getString("data");
Toast.makeText(getBaseContext(), date, Toast.LENGTH_SHORT).show();
} catch ( JSONException e) {
e.printStackTrace();
}
}
private String getJsonData(){
StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
.detectDiskReads()
.detectDiskWrites()
.detectNetwork()
.penaltyLog()
.build());
String str = "";
HttpResponse response;
HttpClient myClient = new DefaultHttpClient();
HttpPost myConnection = new HttpPost("url_php_file_with_JSON");
try {
response = myClient.execute(myConnection);
str = EntityUtils.toString(response.getEntity(), "UTF-8");
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return str;
}
}
//comparison variable (from String date=json.getString("data")) with an other static variable
How to correctly display variable String date = json.getString ( "data") for comparison in other functions?
While it is displayed in the function receiving a variable using Toast.makeText, and I have to work with it in other areas of the java file

You need to make your String a global variable, like follows:
public class ListviewActivity extends Activity {
private String date;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String json_str = getJsonData();
try{
JSONArray jArray = new JSONArray(json_str);
JSONObject json = null;
json = jArray.getJSONObject(0);
date=json.getString("data");
Toast.makeText(getBaseContext(), date, Toast.LENGTH_SHORT).show();
} catch ( JSONException e) {
e.printStackTrace();
}
}
// The rest of your code
}
That way, you can use it freely anywhere in your class.

want to send listview data to another activity in android

package com.example.selflistview;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.StrictMode;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
TextView text;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
connect();
}
private void connect() {
String data;
List<String> r = new ArrayList<String>();
ArrayAdapter<String>adapter=new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1,r);
ListView list=(ListView)findViewById(R.id.listView1);
try {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet("http://localhost/listview.php");
HttpResponse response = client.execute(request);
HttpEntity entity=response.getEntity();
data=EntityUtils.toString(entity);
Log.e("STRING", data);
try {
JSONArray json=new JSONArray(data);
for(int i=0;i<json.length(); i++)
{
JSONObject obj=json.getJSONObject(i);
String name=obj.getString("name");
String year=obj.getString("year");
String age=obj.getString("age");
Log.e("STRING", name);
r.add(name);
//r.add(year);
//r.add(age);
list.setAdapter(adapter);
list.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,long arg3) {
// TODO Auto-generated method stub
//final String item = (String) arg0.getItemAtPosition(arg2);
Toast.makeText(getBaseContext(), "arg2 : "+arg2, Toast.LENGTH_SHORT).show();
Intent view_det = new Intent(getBaseContext(),ViewDetail.class);
view_det.putExtra("position",arg2);
startActivity(view_det);
}
});
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (ClientProtocolException e) {
Log.d("HTTPCLIENT", e.getLocalizedMessage());
} catch (IOException e) {
Log.d("HTTPCLIENT", e.getLocalizedMessage());
}
}
}
I want to send Year, name and age to another activity, i am able to get the positions at intent but not the other values. please help...
I am able to see those values in list., but not able to call at intent section.
Your help will be appreciated..

This might help
Public class MainActivity extends Activity {
TextView text;
List<String> r; //define list here
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
connect();
}
private void connect() {
String data;
r = new ArrayList<String>();
try {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet("http://localhost/listview.php");
HttpResponse response = client.execute(request);
HttpEntity entity=response.getEntity();
data=EntityUtils.toString(entity);
Log.e("STRING", data);
try {
JSONArray json=new JSONArray(data);
for(int i=0;i<json.length(); i++)
{
JSONObject obj=json.getJSONObject(i);
String name=obj.getString("name");
String year=obj.getString("year");
String age=obj.getString("age");
Log.e("STRING", name);
r.add(name);
//r.add(year);
//r.add(age);
}
ArrayAdapter<String>adapter=new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1,r);
ListView list=(ListView)findViewById(R.id.listView1);
list.setAdapter(adapter);
list.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,long arg3) {
// TODO Auto-generated method stub
//final String item = (String) arg0.getItemAtPosition(arg2);
Toast.makeText(getBaseContext(), "arg2 : "+arg2, Toast.LENGTH_SHORT).show();
Intent view_det = new Intent(getBaseContext(),ViewDetail.class);
view_det.putExtra("position",arg2);
String name = r.get(arg2);//add this line to get name from the arraylist of that position
JSONObject obj=json.getJSONObject(arg2); //you can get other two values from json object
String year=obj.getString("year");
String age=obj.getString("age");
view_det.putExtra("name",name); //add this
view_det.putExtra("year",year); //add this
view_det.putExtra("age",age); //add this
startActivity(view_det);
}
});
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (ClientProtocolException e) {
Log.d("HTTPCLIENT", e.getLocalizedMessage());
} catch (IOException e) {
Log.d("HTTPCLIENT", e.getLocalizedMessage());
}
}
}

Android-Json parser not able to display data retrieved from back end

I am new to android. I am implementing a project in which I want to get the data from the back end and display on my android screen.
The Json I am trying to call is:-
[{"admin":null,"card_no":"8789","created_at":"2013-04-09T12:55:54Z","deleted":0,"email":"dfds#fgfd.com","entered_by":null,"first_name":"Gajanan","id":8,"last_name":"Bhat","last_updated_by":null,"middle_name":"","mobile":87981,"updated_at":"2013-04-13T05:26:25Z","user_type_id":null},{"admin":{"created_at":"2013-04-10T09:02:00Z","deleted":0,"designation":"Sr software Engineer","email":"admin#qwe.com","first_name":"Chiron","id":1,"last_name":"Synergies","middle_name":"Sr software Engineer","office_phone":"98789765","super_admin":false,"updated_at":"2013-04-10T12:03:04Z","username":"Admin"},"card_no":"66","created_at":"2013-04-08T09:47:15Z","deleted":0,"email":"rajaarun1991","entered_by":1,"first_name":"Arun","id":1,"last_name":"Raja\n","last_updated_by":1,"middle_name":"Nagaraj","mobile":941,"updated_at":"2013-04-08T09:47:15Z","user_type_id":1}]
My JsonParser.java is as follows:-
package com.example.library;
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.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.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
import android.util.Log;
public class JSONParser {
static InputStream is = null;
static JSONArray jarray = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONArray getJSONFromUrl(String url) {
StringBuilder builder = new StringBuilder();
HttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
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);
}
} else {
Log.e("==>", "Failed to download file");
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// try parse the string to a JSON object
try {
jarray = new JSONArray( builder.toString());
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jarray;
}
}
/* public void writeJSON() {
JSONObject object = new JSONObject();
try {
object.put("name", "");
object.put("score", new Integer(200));
object.put("current", new Double(152.32));
object.put("nickname", "Programmer");
} catch (JSONException e) {
e.printStackTrace();
}
System.out.println(object);
}
*/
And my activity.java is as follows:-
package com.example.library;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
public class SecondActivity extends Activity
{
private Context context;
private static String url = "http://192.168.0.100:3000/users.json";
private static final String TAG_ID = "id";
private static final String TAG_FIRST_NAME = "first_name";
private static final String TAG_MIDDLE_NAME = "middle_name";
private static final String TAG_LAST_NAME = "last_name";
// private static final String TAG_POINTS = "experiencePoints";
ArrayList<HashMap<String, String>> jsonlist = new ArrayList<HashMap<String, String>>();
ListView lv ;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new ProgressTask(SecondActivity.this).execute();
}
private class ProgressTask extends AsyncTask<String, Void, Boolean> {
private ProgressDialog dialog;
public ProgressTask(SecondActivity secondActivity) {
Log.i("1", "Called");
context = secondActivity;
dialog = new ProgressDialog(context);
}
/** progress dialog to show user that the backup is processing. */
/** application context. */
private Context context;
protected void onPreExecute() {
this.dialog.setMessage("Progress start");
this.dialog.show();
}
#Override
protected void onPostExecute(final Boolean success) {
if (dialog.isShowing()) {
dialog.dismiss();
}
ListAdapter adapter = new SimpleAdapter(context, jsonlist,
R.layout.list_item, new String[] { TAG_ID, TAG_FIRST_NAME,
TAG_MIDDLE_NAME, TAG_LAST_NAME }, new int[] {
R.id.id, R.id.first_name, R.id.middle_name,
R.id.last_name });
setListAdapter(adapter);
// selecting single ListView item
lv = getListView();
}
private void setListAdapter(ListAdapter adapter) {
// TODO Auto-generated method stub
}
protected Boolean doInBackground(final String... args) {
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONArray json = jParser.getJSONFromUrl(url);
for (int i = 0; i < json.length(); i++) {
try {
JSONObject c = json.getJSONObject(i);
String id = c.getString(TAG_ID);
String first_name = c.getString(TAG_FIRST_NAME);
String middle_name = c.getString(TAG_MIDDLE_NAME);
String last_name = c.getString(TAG_LAST_NAME);
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_ID, id);
map.put(TAG_FIRST_NAME, first_name);
map.put(TAG_MIDDLE_NAME, middle_name);
map.put(TAG_LAST_NAME, last_name);
jsonlist.add(map);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return null;
}
}
public ListView getListView() {
// TODO Auto-generated method stub
return null;
}
}
I am not able to show anything on the emulators for users,whereas I am able to fetch the data from the server
Actually in the project I want to display all the users present in the library.I am accessing the server which is on Ubuntu.
The following message is displayed on the console(Terminal):-
Started GET "/users.json" for 192.168.0.104 at 2013-05-05 22:05:01 -0700
Processing by UsersController#index as JSON
User Load (0.4ms) SELECT "users".* FROM "users" WHERE (users.deleted = 0) ORDER BY users.id DESC
Admin Load (0.3ms) SELECT "admins".* FROM "admins" WHERE "admins"."id" = 1 AND (admins.deleted = 0) ORDER BY admins.id DESC LIMIT 1
Completed 200 OK in 4ms (Views: 2.1ms | ActiveRecord: 0.6ms)
[2013-05-05 22:05:01] WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true
However i am not able to display the data on the android screen/emulator.
Please help me with this.

I missed your setAdapterList()method.
Any error for your json pasers? and can you put your activity which is inherited from SecondActivity?
//modify getListView
public ListView getListView() {
// TODO Auto-generated method stub
listView = (ListView)findViewById(r.your.listview);
return listView;
}
//modify setListAdapter
private void setListAdapter(ListAdapter adapter) {
// TODO Auto-generated method stub
lv.setAdapter(adapter);
}

passing json data to a custom object - android

I'm having trouble with my application. I'm trying to pass json data from my database in a custom class in android, and then display this in a list. When i run my app nothing happens, no errors, no list displayed. if anyone can help i would be very grateful!! :)
All the network stuff is done in async, and im trying to return the an array of objects so i suspect that this could be the problem is here or else when i am converting the string from the httphandler class into a JSONArray.
this is my main activity
package com.example.test1;
import java.util.ArrayList;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.net.ParseException;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class clubpage extends Activity {
class Programme {
public String name;
public String event;
public String price;
}
String clubphp = "http://10.0.2.2/corkgaa/Nemo.php";
String progString;
ArrayList<Programme> Programmedata = new ArrayList<Programme>();
ListView clublistview = (ListView)findViewById(R.id.listview1);
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.clubpage);
new Dbhandler().execute(clubphp);
ArrayAdapter<Programme> adapter = new ArrayAdapter<Programme>(this,
android.R.layout.simple_list_item_1, Programmedata);
clublistview.setAdapter(adapter);
}
public class Dbhandler extends AsyncTask<String, Void, ArrayList<Programme>> {
protected ArrayList<Programme> doInBackground(String... arg0) {
ArrayList<Programme> arraydata = new ArrayList<Programme>();
progString = httphandler.HttpGetExec(clubphp);
try{
JSONArray jArray = new JSONArray(progString);
JSONObject json_data=null;
for(int i=0;i<jArray.length();i++){
json_data = jArray.getJSONObject(i);
Programme Progresult = new Programme();
Progresult.name = json_data.getString("Name");
Progresult.event = json_data.getString("Event");
Progresult.price = json_data.getString("Price");
arraydata.add(Progresult);
}
}
catch(JSONException e1){
}
catch (ParseException e1) {
e1.printStackTrace();
}
return arraydata;
}
#Override
protected void onPostExecute(ArrayList<Programme> result) {
Programmedata = result;
}
}
#Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
}
}
httphandler class here:
package com.example.test1;
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;
import android.util.Log;
public class httphandler {
//Main Dev setup
public static String HttpGetExec (String URI) {
// TODO Auto-generated method stub
String result = "no response";
InputStream is = null;
StringBuilder sb = null;
//http post
try{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://10.0.2.2/corkgaa/Nemo.php");
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());
}
return result;
//aa=new ArrayAdapter<String>(clubpage.this, R.layout.listrow, R.id.title, result);
//ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,R.layout.listrow, R.id.title, result);
//listview.setAdapter(aa);
}
}

Move this line to your onCreate after setContentView
clublistview = (ListView)findViewById(R.id.listview1);
And move the following lines to onPostExecute in your async task:
ArrayAdapter<Programme> adapter = new ArrayAdapter<Programme>(this,
android.R.layout.simple_list_item_1, Programmedata);
clublistview.setAdapter(adapter);
While your async task is executing, consider showing some kind of progress indicator.

Not getting the output

I'm trying to get the data from the database for which I created a php file. It returns the name as the reply to the call. the website it Ensignweb
the program code goes like this.
The php file is like this
<?php
$connect = mysql_connect("localhost","databasename","password");
mysql_select_db("ews_app");
$query = mysql_query("select name from comment");
if(!empty($query)){
if(mysql_num_rows($query)>0){
WHILE($row=mysql_fetch_array($query)):
$comment = array();
$comment["name"] = $row['name'];
echo "$comment<br>";
echo json_encode($comment);
echo "<br>";
endwhile;
}
}
?>
The java code goes like this:
import java.io.IOException;
import java.io.Reader;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
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.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.Menu;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
TextView httpStuff;
HttpClient client;
JSONObject json;
final static String URL = "http://www.ensignweb.com/sandbox/app/comment11.php";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
httpStuff = (TextView) findViewById(R.id.data);
client = new DefaultHttpClient();
new Read().execute("name");
}
public JSONObject lastTweet() throws ClientProtocolException,IOException,JSONException{
StringBuilder url = new StringBuilder(URL);
HttpGet get = new HttpGet(url.toString());
HttpResponse r = client.execute(get);
int status = r.getStatusLine().getStatusCode();//return 200 if execution is success
if(status==200){
HttpEntity e = r.getEntity();
String data = EntityUtils.toString(e);
JSONArray timeline = new JSONArray(data);
JSONObject last = timeline.getJSONObject(0);
return last;
}else{
Toast.makeText(MainActivity.this, "error", Toast.LENGTH_LONG);
return null;
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
public class Read extends AsyncTask<String, Integer, String>{
#Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
try {
json = lastTweet();
return json.toString();
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
httpStuff.setText(result);
}
}
}
But It is not displaying the json reply. I'm stucked in it from past few days.
Please help me out of it. I really need it.