How to extract the URL following an HTTPPost in Android - java

I'm scratching my head at this problem that I can't seem to figure out. What I'm trying to do is extract the URL following the HTTPpost. This will allow me to go through the Oauth process.
Currently I'm extracting the whole website into my entity.
For example: The data will be posted to https://mysite.com/login and will redirect after the post to https://mysite.com/dashboard?code=3593085390859082093720
How does one extract the url?
If you need any more information or can direct me in the right direction, all is appreciated! Thank you!
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class LoginActivity extends Activity implements OnClickListener {
Button ok,back,exit;
TextView result;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
// Login button clicked
ok = (Button)findViewById(R.id.submit);
ok.setOnClickListener(this);
result = (TextView)findViewById(R.id.result);
}
public void postLoginData() {
// Create a new HttpClient and Post Header
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("https://mysite.com/login");
try {
// Add user name and password
EditText uname = (EditText)findViewById(R.id.username);
String username = uname.getText().toString();
EditText pword = (EditText)findViewById(R.id.password);
String password = pword.getText().toString();
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("pseudonym_session[unique_id]", username));
nameValuePairs.add(new BasicNameValuePair("pseudonym_session[password]", password));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
Log.w("CANVAS", "Execute HTTP Post Request");
HttpResponse response = httpclient.execute(httppost);
String str = inputStreamToString(response.getEntity().getContent()).toString();
Log.w("CANVAS", str);
ResponseHandler<String> responseHandler = new BasicResponseHandler();
String ResponseBody = httpclient.execute(httppost, responseHandler);
Intent intent = new Intent(getBaseContext(), DashboardActivity.class);
startActivity(intent);
if(str.toString().equalsIgnoreCase("true"))
{
Log.w("CANVAS", "TRUE");
result.setText("Login successful");
}else
{
Log.w("CANVAS", "FALSE");
result.setText(ResponseBody);
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private StringBuilder inputStreamToString(InputStream is) {
String line = "";
StringBuilder total = new StringBuilder();
// Wrap a BufferedReader around the InputStream
BufferedReader rd = new BufferedReader(new InputStreamReader(is));
// Read response until the end
try {
while ((line = rd.readLine()) != null) {
total.append(line);
}
} catch (IOException e) {
e.printStackTrace();
}
// Return full string
return total;
}
#Override
public void onClick(View view) {
if(view == ok){
postLoginData();
}
}
}

if you set a redirect handler, you can get back from the response the location the server's sending you to. here's a snippet of code I was just playing with... (and I should point out, if you DON'T set a redirect handler, you'll just get redirected to the final destination, which might be the login screen itself)
DefaultHttpClient htc = getHttpClient();
htc.setRedirectHandler(new RedirectHandler() {
#Override
public boolean isRedirectRequested(HttpResponse response, HttpContext context)
{
Log.d(TAG, "isRedirectRequested, response: " + response.toString());
return false;
}
#Override
public URI getLocationURI(HttpResponse response, HttpContext context)
throws ProtocolException
{
Log.d(TAG, "getLocationURI, response: " + response.toString());
return null;
}
});
HttpResponse resp = null;
StringBuilder out = new StringBuilder();
try
{
HttpGet get = new HttpGet(spec);
resp = htc.execute(get);
for (Header hdr : resp.getAllHeaders())
Log.d(TAG, "header " + hdr.getName() + " -> " + hdr.getValue());
...
}
catch (Exception e)
{
Log.e(TAG, "Error connecting to " + spec, e);
return null;
}

Search for a substring in the HttpPost url

Related

null pointer exception error in http POST request JSON object

I am doing android coding and sending a http POST request using httpClient. and it is giving me a null point expception error at the line
httpEntity = httpResponse.getEntity();
i used log cat and found that my code was stopping at the line mentioned above. please help me out with it. thanks in advance.
my code is for the establishment of http client is in the file serviceHandler:
package com.example.manumaheshwari.vigo;
/**
* Created by ManuMaheshwari on 30/06/15.
*/
import android.util.Log;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
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.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;
public class ServiceHandler {
static String response = null;
public final static int GET = 1;
public final static int POST = 2;
StringBuilder sb;
public ServiceHandler() {
}
/**
* Making service call
* #url - url to make request
* #method - http request method
* */
public String makeServiceCall(String url, int method) {
return this.makeServiceCall(url, method, null);
}
/**
* Making service call
* #url - url to make request
* #method - http request method
* #params - http request params
* */
public String makeServiceCall(String url, int method, List<NameValuePair> params) {
try {
// http client
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpEntity httpEntity = null;
HttpResponse httpResponse = null;
// Checking http request method type
if (method == POST) {
HttpPost httpPost = new HttpPost(url);
httpPost.setHeader(HTTP.CONTENT_TYPE, "application/x-www-form-urlencoded ");
if (params != null) {
try {
httpPost.setEntity(new UrlEncodedFormEntity(params, "utf-8"));
}
catch (UnsupportedEncodingException e) {
// writing error to Log
e.printStackTrace();
}
// Making HTTP Request
try {
HttpResponse response = httpClient.execute(httpPost);
// writing response to log
Log.d("Http Response: ", response.toString());
} catch (ClientProtocolException e) {
// writing exception to log
e.printStackTrace();
} catch (IOException e) {
// writing exception to log
e.printStackTrace();
}
}
} else if (method == GET) {
// appending params to url
if (params != null) {
String paramString = URLEncodedUtils.format(params, "utf-8");
url += "?" + paramString;
}
HttpGet httpGet = new HttpGet(url);
httpResponse = httpClient.execute(httpGet);
}
httpEntity = httpResponse.getEntity();
response = EntityUtils.toString(httpEntity);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return response;
}
}
and the code for my main activity is as follows:
package com.example.manumaheshwari.vigo;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
public class MainActivity extends ListActivity {
private ProgressDialog pDialog;
// URL to get pending rides JSON
private static String url = "http://128.199.206.145/vigo/v1/displayalldrivers";
// JSON Node names
private static final String TAG_SOURCE = "source";
private static final String TAG_DESTINATION = "destination";
private static final String TAG_DRIVER_ID = "driver_id";
private static final String TAG_NAME = "name";
// pending rides JSONArray
JSONArray pendingRides = null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> pendingRidesList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pendingRidesList = new ArrayList<HashMap<String, String>>();
ListView lv = getListView();
// Calling async task to get json
new GetRides().execute();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* Async task class to get json by making HTTP call
* */
private class GetRides extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
#Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("contractor_id", "1"));
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.POST, nameValuePairs);
Log.d("Response: " , "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
pendingRides = jsonObj.getJSONArray("driver");
// looping through All Contacts
for (int i = 0; i < pendingRides.length(); i++) {
JSONObject c = pendingRides.getJSONObject(i);
String source = c.getString(TAG_NAME);
String destination = c.getString(TAG_DRIVER_ID);
// tmp hashmap for single contact
HashMap<String, String> pendingRide = new HashMap<String, String>();
// adding each child node to HashMap key => value
pendingRide.put(TAG_NAME, source);
pendingRide.put(TAG_DRIVER_ID, destination);
// adding pending ride to pending ride list
pendingRidesList.add(pendingRide);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
MainActivity.this, pendingRidesList,
R.layout.list_view, new String[] { TAG_SOURCE, TAG_DESTINATION,}, new int[] { R.id.source,R.id.destination});
setListAdapter(adapter);
}
}
}
It seems that httpResponse is null,because in POST method you didn't assign any value to it.So in POST method,change
HttpResponse response = httpClient.execute(httpPost);
// writing response to log
Log.d("Http Response: ", response.toString());
to
httpResponse = httpClient.execute(httpPost);
// writing response to log
Log.d("Http Response: ", httpResponse.toString());

Android - Get HTTP Post Response in other activity

I created two activities one contains some text fields which accepts data. From other activity(Async Task) this data is sent to the server and gets the response from the server.
I am able to log the response but unable to store that response in variable and user in other activities. Is there any way to do that?
Here is one activity,
RegisterDevice.java
package sys.darpan.tracking;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class RegisterDevice extends Activity{
EditText regEmail, regPassword, regImei, regDeviceName, regVehicleNumber;
Button regButton;
AsyncRegisterDevice asd;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.register_device);
regEmail = (EditText)findViewById(R.id.regEmail);
regPassword = (EditText)findViewById(R.id.regPassword);
regVehicleNumber = (EditText)findViewById(R.id.regVehicleNum);
regImei = (EditText)findViewById(R.id.regImei);
regDeviceName = (EditText)findViewById(R.id.regDeviceName);
regButton = (Button)findViewById(R.id.regButton);
regImei.setText("165465416416416");
regDeviceName.setText("GT-I9300");
regButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
registerDevice();
}
});
}
protected void registerDevice(){
asd = new AsyncRegisterDevice();
String email = regEmail.getText().toString();
String password = regPassword.getText().toString();
String imei = regImei.getText().toString();
String deviceName = regDeviceName.getText().toString();
String vehicleNo = regVehicleNumber.getText().toString();
String aobj[] = new String[5];
aobj[0] = email;
aobj[1] = password;
aobj[2] = vehicleNo;
aobj[3] = imei;
aobj[4] = deviceName;
asd.execute(aobj);
}
}
Here is Async Task,
package sys.darpan.tracking;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import org.apache.http.HttpResponse;
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;
import android.os.AsyncTask;
import android.util.Log;
public class AsyncRegisterDevice extends AsyncTask<String, String, String> {
String sb;
String finalResult;
#Override
protected String doInBackground(String... params) {
String email = params[0];
String password = params[1];
String vnumber = params[2];
String imei = params[3];
String deviceName = params[4];
DefaultHttpClient defaulthttpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://logicvibes.com/vts/register-device.php");
ArrayList<BasicNameValuePair> arraylist = new ArrayList<BasicNameValuePair>(5);
arraylist.add(new BasicNameValuePair("email", email));
arraylist.add(new BasicNameValuePair("pass", password));
arraylist.add(new BasicNameValuePair("vno", vnumber));
arraylist.add(new BasicNameValuePair("imei", imei));
arraylist.add(new BasicNameValuePair("dname", deviceName));
try
{
httppost.setEntity(new UrlEncodedFormEntity(arraylist));
httppost.getAllHeaders();
}
catch (UnsupportedEncodingException unsupportedencodingexception)
{
unsupportedencodingexception.printStackTrace();
}
try {
// HttpResponse is an interface just like HttpPost.
//Therefore we can't initialize them
HttpResponse httpResponse = defaulthttpclient.execute(httppost);
// According to the JAVA API, InputStream constructor do nothing.
//So we can't initialize InputStream although it is not an interface
InputStream inputStream = httpResponse.getEntity().getContent();
InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
StringBuilder stringBuilder = new StringBuilder();
String bufferedStrChunk = null;
while((bufferedStrChunk = bufferedReader.readLine()) != null){
stringBuilder.append(bufferedStrChunk);
}
sb = stringBuilder.toString();
Log.d("Custom resp: ", sb);
}
catch(Exception e){
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String sb) {
Log.d("RESULT", "Result : " + sb);//this returns NULL
finalResult = sb;
}
public String getFinalResult() {
return finalResult;
}
}
I searched a lot but no luck, please tell me the proper way to do this.
Solved it by using,
try {
asd.execute(aobj).get();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
The main thread waits until the async task finished processing. (good for short processes)

Send JSON from Java to PHP through Post

I am doing an Android program that is supposed to send data from the tablet to a PHP Web Service. The code for sending the JSON:
package com.example.shvalidation;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicHeader;
import org.apache.http.protocol.HTTP;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.View;
public class MainMenuScreen extends Activity {
//JSON Variables
JSONParser jsonParser = new JSONParser();
String pid;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_menu_layout);
new TestThread().execute();
}
#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_layout, menu);
return true;
}
public void PlantToDome(View view) {
Intent intent = new Intent(this, SelectLocationScreen.class);
startActivity(intent);
}
//Código del Web Service
public class TestThread extends AsyncTask<Void, Void, Void> {
ProgressDialog dialog;
protected void onPreExecute() {
dialog = ProgressDialog.show(MainMenuScreen.this, "Loading", "Loading data, please wait..");
}
private String convertStreamToString(InputStream is) {
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}
protected Void doInBackground(Void...args0) {
try {
HttpClient client = new DefaultHttpClient();
HttpResponse response;
HttpPost post = new HttpPost("http://192.168.1.101:8080/GetBook.php");
JSONObject holder = new JSONObject();
JSONObject euid = new JSONObject();
euid.put("euid", 1);
holder.accumulate("euids", euid);
euid.put("euid", 2);
holder.accumulate("euids", euid);
post.setHeader("json", holder.toString());
StringEntity se = new StringEntity(holder.toString());
se.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
post.setEntity(se);
response = client.execute(post);
if (response != null) {
InputStream in = response.getEntity().getContent();
String a = convertStreamToString(in);
Log.i("Read from Server", a);
}
} catch (Exception e) {
Log.d("error", e.toString());
}
return null;
}
protected void onPostExecute(Void unused) {
dialog.dismiss();
}
}
}
The PHP Web Service:
<?php
ob_start();
var_dump(json_decode(file_get_contents('php://input')));
$out = ob_get_contents();
ob_end_clean();
$f = fopen('out.txt', 'w+');
fwrite($f, html_entity_decode($out));
fclose($f);
?>
I have tried different methods for getting the JSON, but none of them have worked for me. Maybe the fine people of StackOverflow can help me out with this, as they always have for every other problem that I've had.
From the comments section, it appears you only want the JSON being sent to your PHP script. Normally, you post POST this to PHP, and extract it:
<?php
print_r($_POST);
$json_string = $_POST['message'];
$json = json_decode($json_string);
print_r($json);
?>
And then a small client example:
public static void main(String[] args) {
String json = "{\"message\":\"This is a message\"}";
HttpClient httpClient = new DefaultHttpClient();
try {
HttpPost request = new HttpPost("http://somesite.com/test.php");
StringEntity params =new StringEntity("message=" + json);
request.addHeader("content-type", "application/x-www-form-urlencoded");
request.setEntity(params);
HttpResponse response = httpClient.execute(request);
// handle response here...
System.out.println(org.apache.http.util.EntityUtils.toString(response.getEntity()));
org.apache.http.util.EntityUtils.consume(response.getEntity());
} catch (Exception ex) {
// handle exception here
} finally {
httpClient.getConnectionManager().shutdown();
}
}
The output of this is:
Array
(
[message] => {"message":"This is a message"}
)
stdClass Object
(
[message] => This is a message
)

unable to call method

I'm trying to implement ZXing barcode scanner into my program. After getting the scanned result, I wanted to parse the result to a method named getData() which belong to another Java class. No syntax error on IDE, but mysql.getData(contents) won't call the method no matter what. Please advise.
If I put this code under onCreate, the whole program force closed:
package com.posQR.ip;
import com.posQR.ip.MySQL;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class PosQRActivity extends Activity{
MySQL mysql;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mysql.getData("productID");
Button button = (Button)findViewById(R.id.button1);
button.setOnClickListener(scanListener);
}
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
TextView textView = (TextView)findViewById(R.id.textView1);
if (requestCode == 0) {
if (resultCode == RESULT_OK) {
try {
String contents = intent.getStringExtra("SCAN_RESULT");
Toast.makeText(getApplicationContext(), contents + "from main", Toast.LENGTH_LONG).show();
mysql.getData(contents);
String string = Double.toString(mysql.getPrice());
textView.setText(string);
}
catch (Exception e) {
Toast.makeText(getApplicationContext(), "Please scan on the product's QR Code.", Toast.LENGTH_LONG).show();
}
} else if (resultCode == RESULT_CANCELED) {
// Handle cancel
}
}
}
private OnClickListener scanListener = new OnClickListener() {
public void onClick(View v) {
try{
Intent intent = new Intent("com.google.zxing.client.android.SCAN");
intent.putExtra("SCAN_MODE", "QR_CODE_MODE");
startActivityForResult(intent, 0);
}
catch (Exception e){
Toast.makeText(getApplicationContext(), "error opening scanner.", Toast.LENGTH_SHORT).show();
}
}
};
}
.
package com.posQR.ip;
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.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.content.Context;
import android.net.ParseException;
import android.util.Log;
import android.widget.Toast;
public class MySQL{
double Price;
private Context localContext;
public void getData(String productID) {
InputStream is = null;
String result = "";
Toast.makeText(localContext.getApplicationContext(), productID, Toast.LENGTH_LONG).show();
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("id",productID));
//http post
try{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://dl.dropbox.com/u/11233767/mysqlRequest.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 br = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
} catch (Exception e) {
// TODO: handle exception
Toast.makeText(localContext.getApplicationContext(), "Error converting result.", Toast.LENGTH_LONG).show();
}
//paring data
try{
JSONArray jArray = new JSONArray(result);
JSONObject json_data=null;
json_data = jArray.getJSONObject(0);
Price=json_data.getDouble("price");
}
catch(JSONException e1){
Toast.makeText(localContext.getApplicationContext(), "No City Found" ,Toast.LENGTH_LONG).show();
} catch (ParseException e1) {
e1.printStackTrace();
}
}
public double getPrice(){
return Price;
}
}
There are many problems here, such as:
the mysql variable is null when you use it in onCreate, you must declare it.
The localContext object in MySql is never initialized, which will cause another NullPointerException when you call getData(). You should create a constructor that accepts a Context object for the MySql class, and use that constructor when you're fixing the first problem. Alternatively you could pass a Context object to getData()
the getData() method accesses the network in the main/UI thread, which will cause another Exception. Call this method in a different thread or spin off a new thread within the method itself. You may want to use an AsyncTask

Downloading Tweets via JSON feed code not working

I'm building my first android app - something that will display my tweets in a list.
I managed to get the app working earlier, but the tweets would sometimes take a long time to download, and the app would become unresponsive or crash.
I decided to add a thread to the app so the it wouldn't become unresponsive, but now it doesn't work at all :/
Does anyone know what's wrong? It's only my third day of learning java, and I can't seem to figure out what the problem is here.
Here's the code:
package com.app.first;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
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.JSONObject;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.widget.ArrayAdapter;
public class Twitter extends ListActivity {
public ProgressDialog pd = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
// Show the ProgressDialog on this thread
pd = ProgressDialog.show(this, "Working..", "Downloading Data...",
true, false);
new LoadTwitterFeed().execute();
}
public class LoadTwitterFeed extends AsyncTask<String, Integer, String> {
String tweets[] = new String[9];
public String readTwitterFeed() {
StringBuilder builder = new StringBuilder();
HttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(
"https://api.twitter.com/1/statuses/user_timeline.json?screen_name=jjmpsp&include_rts=false&count=10");
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(ParseJSON.class.toString(), "Failed to download file");
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return builder.toString();
}
#Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
String readTwitterFeed = readTwitterFeed();
try {
JSONArray jsonArray = new JSONArray(readTwitterFeed);
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
tweets[i] = jsonObject.getString("text").toString();
}
} catch (Exception e) {
e.printStackTrace();
}
setListAdapter(new ArrayAdapter<String>(Twitter.this,
android.R.layout.simple_list_item_1, tweets));
return null;
}
#Override
protected void onPostExecute(String result) {
// what to do when the task ends.
pd.hide();
}
}
}
set this code in onPostExecute
setListAdapter(new ArrayAdapter<String>(Twitter.this,
android.R.layout.simple_list_item_1, tweets));

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