I am new to Android and I am trying to make am simple APP the access a server and read a table in a database. I used this example http://www.androidhive.info/2012/05/how-to-connect-android-with-php-mysql/ and tried to make some adaptations.
There has been many errors that I was able to solve searching here, but on this case I haven´t been luck so far.
As suggest, I did some debbuging and the app stops working when to line 108
try{
//Verificando a TAG Sucesso
int sucess = json.getInt(TAG_SUCESSO);
For the varibles, just befor that, json appears as null.
As it seens I am having trouble to get the response from my PHP code (it shows the right array and executed) to the app.
Here is the Logcat error
12-22 11:50:35.609 1273-1293/br.com.agenciaeisberg.qm E/Buffer Error﹕ Error converting result java.lang.NullPointerException: lock == null
12-22 11:50:35.859 1273-1293/br.com.agenciaeisberg.qm E/JSON Parser﹕ Error parsing data org.json.JSONException: End of input at character 0 of
12-22 11:50:35.859 1273-1293/br.com.agenciaeisberg.qm W/dalvikvm﹕ threadid=12: thread exiting with uncaught exception (group=0xb2a24ba8)
12-22 11:50:36.799 1273-1293/br.com.agenciaeisberg.qm E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1
Process: br.com.agenciaeisberg.qm, PID: 1273
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.NullPointerException
at br.com.agenciaeisberg.qm.ListagemHospitaisActivity$LoadListagemHospitais.doInBackground(ListagemHospitaisActivity.java:104)
at br.com.agenciaeisberg.qm.ListagemHospitaisActivity$LoadListagemHospitais.doInBackground(ListagemHospitaisActivity.java:76)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
12-22 11:50:38.039 1273-1273/br.com.agenciaeisberg.qm W/EGL_emulation﹕ eglSurfaceAttrib not implemented
12-22 11:50:39.259 1273-1273/br.com.agenciaeisberg.qm E/WindowManager﹕ android.view.WindowLeaked: Activity br.com.agenciaeisberg.qm.ListagemHospitaisActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{b2ce6d30 V.E..... R......D 0,0-320,96} that was originally added here
at android.view.ViewRootImpl.<init>(ViewRootImpl.java:348)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:248)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
at android.app.Dialog.show(Dialog.java:286)
at br.com.agenciaeisberg.qm.ListagemHospitaisActivity$LoadListagemHospitais.onPreExecute(ListagemHospitaisActivity.java:88)
at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:587)
at android.os.AsyncTask.execute(AsyncTask.java:535)
at br.com.agenciaeisberg.qm.ListagemHospitaisActivity.onCreate(ListagemHospitaisActivity.java:59)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Here is the Activity
package br.com.agenciaeisberg.qm;
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.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 ListagemHospitaisActivity extends ListActivity {
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> ListaHospitais;
//url para lista hospitais
private static String url_lista_hospitais = "http://127.0.0.1/QM/lista_hospitais.php";
//JSON Node names
private static final String TAG_HOSPITAIS = "hospitais";
private static final String TAG_PID = "pid";
private static final String TAG_NOME = "nome";
private static final String TAG_SUCESSO = "sucesso";
//private static final String TAG_LOTACAO = "lotacao";
//private static final String TAG_DATA_LOTACAO = "data_lotacao";
//hospitais JSONARRAY
JSONArray hospitais = null;
@Override
public void onCreate (Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.lista_hospitais);
//Hashmap for ListView
ListaHospitais = new ArrayList<HashMap<String,String>>();
// Carregando hospitais no backgroung
new LoadListagemHospitais().execute();
// Get ListView
//ListView lv = getListView();
//Selecionando um Hospital
//Executa atividade Hospital
//Criar código depois -> pesquisar linhas abaixo
// on seleting single product
// launching Edit Product Screen
}
/**
* Background Async Task para carregar todos os hospitais através de um HTTP Request
*/
class LoadListagemHospitais extends AsyncTask <String, String, String>{
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute(){
super.onPreExecute();
pDialog = new ProgressDialog(ListagemHospitaisActivity.this);
pDialog.setMessage("Aguarde, carregando Hospitais");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* Buscando os hospitais do URL
* */
protected String doInBackground (String... args) {
//Criação dos parâmetros
List<NameValuePair> params = new ArrayList<NameValuePair>();
// Buscando o string JSON do URL
JSONObject json = jParser.makeHttpRequest(url_lista_hospitais,"GET", params);
// Check your log cat for JSON reponse
Log.d("Listagem Hospitais: ", json.toString());
try{
//Verificando a TAG Sucesso
int sucess = json.getInt(TAG_SUCESSO);
if (sucess == 1){
//existe hospital cadastrado
// Buscando Array dos hospitais
hospitais = json.getJSONArray(TAG_HOSPITAIS);
//loop por todos os Hospitais
for (int i = 0; i < hospitais.length(); i++) {
JSONObject c = hospitais.getJSONObject(i);
// Armazenando as variáveis
String id = c.getString(TAG_PID);
String nome = c.getString(TAG_NOME);
// creando novo HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adicionando cada child node ao HashMap . key => value
map.put(TAG_PID, id);
map.put(TAG_NOME, nome);
// adicionando HashList à ArrayList
ListaHospitais.add(map);
}
}else{
// no products found
// Launch Add New product Activity
Intent i = new Intent(getApplicationContext(),
MainActivity.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
}catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// Dismiss a caixa de dialogo depois de buscar todos os items
pDialog.dismiss();
// atualizando UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
ListagemHospitaisActivity.this, ListaHospitais,
R.layout.lista_hospitais, new String[] { TAG_PID,
TAG_NOME},
new int[] { R.id.pid, R.id.nome });
// updating listview
setListAdapter(adapter);
}
});
}
}
}
Here is the JSONParser Class
package br.com.agenciaeisberg.qm;
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;
}
}
Here is the php Code
<?php
/*
* O código a seguir lista todos os hospitais
*/
//array para Resposta JSON
$response = array();
require_once 'geral.inc.php';
// connecting to db
$con = mysqli_connect($hostname, $username, $senha, $banco);
// Listar todos os Hospitais
$result = mysqli_query($con, 'SELECT * FROM hospitais');
$response['hospitais'] = array();
while ($row = mysqli_fetch_array($result)){
//array temporário
$hospital = array ();
$hospital['pid'] = $row['PID'];
$hospital['nome'] = $row['NomeHospital'];
$hospital['lotacao'] = $row['ultima_lotacao'];
$hospital['data_lotacao'] = $row['d_h_ultima_lotacao'];
// Exibe o resultado um a um da array
array_push($response["hospitais"], $hospital);
}
$response["successo"] = 1;
// echoing JSON response
echo json_encode($response);
?>
