Badreddine Makdoudi Badreddine Makdoudi - 20 days ago 8
Android Question

ListFragment inside a view pager

i have a list in my PostgreSql Data Base that i want it to appear in 1 of my 3 viewPager Fragment,
this is the mainActivity code of my application:

package info.androidhive.tabsswipe;

import info.androidhive.tabsswipe.adapter.TabsPagerAdapter;
import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;

public class MainActivity extends FragmentActivity implements ActionBar.TabListener {

private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
// Tab titles
private String[] tabs = { "Top Rated", "Games", "Movies" };

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

// Initilization
viewPager = (ViewPager) findViewById(R.id.pager);
actionBar = getActionBar();
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

viewPager.setAdapter(mAdapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

// Adding Tabs
for (String tab_name : tabs) {
actionBar.addTab(actionBar.newTab().setText(tab_name)
.setTabListener(this));
}

/**
* on swiping the viewpager make respective tab selected
* */
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

@Override
public void onPageSelected(int position) {
// on changing the page
// make respected tab selected
actionBar.setSelectedNavigationItem(position);
}

@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}

@Override
public void onPageScrollStateChanged(int arg0) {
}
});
}

@Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}

@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// on tab selected
// show respected fragment view
viewPager.setCurrentItem(tab.getPosition());
}

@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}

}


This is the ListFragment code:

package info.androidhive.tabsswipe;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.support.v4.app.ListFragment;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListAdapter;
import android.widget.SimpleAdapter;

public class TopRatedFragment extends ListFragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {

View myFragmentView = inflater.inflate(R.layout.fragment_top_rated,
container, false);

return myFragmentView;

}

@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);

}
ArrayList<HashMap<String, String>> interventionsList;
// Progress Dialog
private ProgressDialog pDialog;
// url to get all interventions list
private static String url_all_interventions = "http://10.0.2.2/Scripts/liste_interventions.php";
// Creating JSON Parser object
JSONParser jParser = new JSONParser();

// interventions JSONArray
JSONArray interventions = null;
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);

this.getListView().setTextFilterEnabled(true);

// Hashmap for ListView
interventionsList = new ArrayList<HashMap<String, String>>();

// Loading interventions in Background Thread
new LoadAllInterventions().execute();
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllInterventions extends AsyncTask<String, String, String> {

/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(getActivity());
pDialog.setMessage("Loading interventions. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}

/**
* getting All interventions from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_interventions, "GET", params);

// Check your log cat for JSON reponse
Log.d("All Interventions: ", json.toString());

try {
// Checking for SUCCESS TAG
int success = json.getInt("success");
Log.d("success" , json.toString());
if (success == 1) {
// interventions found
// Getting Array of interventions
interventions = json.getJSONArray("interventions");

// looping through All interventions
for (int i = 0; i < interventions.length(); i++) {
JSONObject c = interventions.getJSONObject(i);

// Storing each json item in variable
String id = c.getString("id");
String name = c.getString("name");

// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();

// adding each child node to HashMap key => value
map.put("Int_id", id);
map.put("Int_name", name);

// adding HashList to ArrayList
interventionsList.add(map);
}
}
} catch (JSONException e) {e.printStackTrace();}
return null;
}

/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
getActivity(), interventionsList,
R.layout.list_item, new String[] { "Int_id",
"Int_name"},
new int[] { R.id.pid, R.id.name });
// updating listview
setListAdapter(adapter);
Log.e("LIST", "setListAdapter is done");
}
});

}

}
public void runOnUiThread(Runnable runnable) {
// TODO Auto-generated method stub

}

}


This is tha TabsPagerAdapter class's code:

package info.androidhive.tabsswipe.adapter;

import info.androidhive.tabsswipe.GamesFragment;
import info.androidhive.tabsswipe.MoviesFragment;
import info.androidhive.tabsswipe.TopRatedFragment;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;

public class TabsPagerAdapter extends FragmentPagerAdapter {

public TabsPagerAdapter(FragmentManager fm) {
super(fm);
}

@Override
public Fragment getItem(int index) {

switch (index) {
case 0:
// Top Rated fragment activity
return new TopRatedFragment();
case 1:
// Games fragment activity
return new GamesFragment();
case 2:
// Movies fragment activity
return new MoviesFragment();
}

return null;
}

@Override
public int getCount() {
// get item count - equal to number of tabs
return 3;
}

}


This is JSONParser class's code:

package info.androidhive.tabsswipe;

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 = "";

// constructor
public JSONParser() {

}

// function get json from url
// by making HTTP POST or GET mehtod
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params) {

// Making HTTP request
try {

// check for request method
if(method == "POST"){
// request method is 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"){
// request method is 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 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;

}
}


This is ListFragment Layout's code:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#99E7E5" >
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
</RelativeLayout>


and this is the php file that communicate with the postgresql data base:

<?php
$hostname_localhost ='localhost';
$port_localhost =5432;
$database_localhost ='techmobi';
$username_localhost ='openpg';
$password_localhost ='openpgpwd';
$localhost = "host='$hostname_localhost' port='$port_localhost' dbname='$database_localhost' user='$username_localhost' password='$password_localhost'";
$connexion =pg_connect($localhost) or die ("Erreur de connexion ".pg_last_error());
$query_search = "select id,name from crm_helpdesk";
$query_exec = pg_query($query_search) or die(pg_error());


$output = array();
while($rows=pg_fetch_assoc($query_exec))
{
$output[]=$rows;
}
echo json_encode($output);
?>


The the application close after running and that what appears in the logCat:
JSONParser error

Please any helps !!!

Answer

The error at the top of the log files is telling you exactly the problem:

Your JSON string is a JSON Array of two JSON objects. But you are trying to parse it as a JSON Object.

Change this line:

   // try parse the string to a JSON object
    try {
        jObj = new JSONObject(json);

To be this:

   // try parse the string to a JSON array
    try {
        jArr = new JSONArray(json);

Where jArr is declared to be of type JSONArray.

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